Hayden Roberts: Playing Hide and Seek with Sonar, July 16, 2019

NOAA Teacher at Sea

Hayden Roberts

Aboard NOAA Ship Oregon II

July 8-19, 2019


Mission: Leg III of SEAMAP Summer Groundfish Survey
Geographic Area of Cruise: Gulf of Mexico
Date: July 16, 2019

Weather Data from the Bridge
Latitude: 28.51° N
Longitude: 84.40° W
Wave Height: 1 foot
Wind Speed: 6 knots
Wind Direction: 115
Visibility: 10 nm
Air Temperature: 30.8°C
Barometric Pressure: 1021 mb
Sky: Clear


Science Log

In my previous blog, I mentioned the challenges of doing survey work on the eastern side of the Gulf near Florida. I also mentioned the use of a probe to scan the sea floor in advance of trawling for fish samples. That probe is called the EdgeTech 4125 Side Scan Sonar. Since it plays a major role in the scientific research we have completed, I wanted to focus on it a bit more in this blog. Using a scanner such as this for a groundfish survey in the Gulf by NOAA is not typical. This system was added as a precaution in advance of trawling due to the uneven nature of the Gulf floor off the Florida Coast, which is not as much of a problem the further west one goes in the Gulf. Scanners such as these have been useful on other NOAA and marine conservation research cruises especially working to map and assess reefs in the Gulf.

deploying side scan
Preparing to put the side scan over board.

Having seen the side scanner used at a dozen different research stations on this cruise, I wanted to learn more about capabilities of this scientific instrument. From the manufacturer’s information, I have learned that it was designed for search and recovery and shallow water surveys. The side scanner provides higher resolution imagery. While the imagining sent to our computer monitors have been mostly sand and rock, one researcher in our crew said he has seen tanks, washing machines, and other junk clearly on the monitors during other research cruises.

This means that the side scanner provides fast survey results, but the accuracy of the results becomes the challenge. While EdgeTech praises the accuracy of its own technology, we have learned that accurate readings of data on the monitor can be more taxing. Certainly, the side scanner is great for defining large items or structures on the sea floor, but in areas where the contour of the floor is more subtle, picking out distinctions on the monitor can be harder to discern. On some scans, we have found the surface of the sea floor to be generally sandy and suitable for trawling, but then on another scan with similar data results, chunks of coral and rock have impeded our trawls and damaged the net.

Side scan readout
Sample scan from monitor in the computer lab. The light areas are sandy bottom. The dark is either seaweed or other plant material or rocks. The challenge is telling the difference.


Did You Know?

In 1906, American naval architect Lewis Nixon invented the first sonar-like listening device to detect icebergs. During World War I, a need to detect submarines increased interest in sonar. French physicist Paul Langévin constructed the first sonar set to detect submarines in 1915. Today, sonar has evolved into more sophisticated forms of digital imaging multibeam technology and side scan sonar (see https://oceanexplorer.noaa.gov/explorations/lewis_clark01/background/seafloormapping/seafloormapping.html for more information).


Personal Log

When I first arrived aboard Oregon II, the new environment was striking. I have never spent a significant amount of time on a trawling vessel or a research ship. Looking around, I took many pictures of the various features with an eye on the architectural elements of the ship. One of the most common fixtures throughout the vessel are posted signs. Lamented signs and stickers can be found all over the ship. At first, I was amused at the volume and redundancy, but then I realized that this ship is a communal space. Throughout the year, various individuals work and dwell on this vessel. The signs serve to direct and try to create consistency in the overall operation of the ship and the experience people have aboard it. Some call the ship “home” for extended periods of time such as most of the operational crew. Others, mostly those who are part of the science party, use the vessel for weeks at a time intermittently. Before I was allowed join the science party, I was required to complete an orientation. That orientation aligns with policies of NOAA and the expectation aboard Oregon II of its crew. From the training, I primarily learned that the most important policy is safety, which interestingly is emblazoned on the front of the ship just below the bridge.

Safety First!
Safety First!

The signs seem to be reflective of past experiences on the ship. Signs are not only reminders of important policies and protocols, but also remembrances of challenges confronted during past cruises. Like the additional equipment that has been added to Oregon II since its commission in 1967, the added signs illustrate the history the vessel has endured through hundreds of excursions.

Oregon II 1967
Bureau of Commercial Fisheries Ship Oregon II (1967), which was later transferred to NOAA when the administration was formed in 1970.
Oregon II 2017
NOAA Ship Oregon II in 2017 on its 50th Anniversary.

Examples of that history is latent in the location and wording of signs. Posted across from me in the computer lab are three instructional signs: “Do not mark or alter hard hats,” “Keep clear of sightglass do not secure gear to sightglass” (a sightglass is an oil gauge), and “(Notice) scientist are to clear freezers out after every survey.”

signs collage
A collage of four signs around NOAA Ship Oregon II
more signs
Another collage of four signs around NOAA Ship Oregon II
even more signs
Another collage of signs around NOAA Ship Oregon II

Author and journalist Daniel Pink talks about the importance of signs in our daily lives. His most recent work has focused on the emotional intelligence associated with signs. Emotional intelligence refers to the way we handle interpersonal relationships judiciously and empathetically. He is all about the way signs are crafted and displayed, but signs should also be thought of in relation to how informative and symbolic they can be within the environment we exist. While the information is usually direct, the symbolism comes from the way we interpret the overall context of the signs in relation to or role they play in that environment.

Lona Hall: Land and Sea, June 12, 2019

NOAA Teacher at Sea

Lona Hall

Aboard NOAA Ship Rainier

June 3 – 14, 2019

Mission: Kodiak Island Hydrographic Survey

Geographic Area of Cruise: Kodiak Island, Alaska

Date: June 12, 2019

Time:  1541 hours

Location: Saltery Cove, Kodiak Island

Weather from the Bridge:

Latitude: 57°29.1009’ N

Longitude: 152°44.0031’ W

Wind Speed: 9.0 knots

Wind Direction: N (10 degrees)

Air Temperature: 12.78° Celsius

Water Temperature: 8.89° Celsius

Lona in immersion suit
All dressed up (in an immersion suit) and no place to go

Science and Technology Log

You may be wondering what role technology plays in a hydrographic survey.  I have already written about how modern survey operations rely on the use of multibeam sonar.  What I have not described, and am still coming to understand myself, is how complex the processing of sonar data is, involving different types of hardware and software.  

For example, when the sonar transducer sends out a pulse, most of the sound leaves and eventually comes back to the boat at an angle.  When sound or light waves move at an angle from one substance into another, or through a substance with varying density, they bend. You have probably observed this before and not realized it.  A plastic drinking straw in a glass of water will appear broken through the glass. That is because the light waves traveling from the straw to your eye bend as they travel.

Refraction in a glass of water
Refraction in a glass of water

The bending of a wave is called refraction. Sound waves refract, too, and this refraction can cause some issues with our survey data. Thanks to technology, there are ways to solve this problem. The sonar itself uses the sound velocity profile from our CTD casts in real time to adjust the data as we collect it. Later on during post processing, some of the data may need to be corrected again, using the CTD cast profiles most appropriate for that area at that general time. Corrections that would be difficult and time-consuming if done by hand are simplified with the use of technology.

Another interesting project in which I’ve been privileged to participate this week was setting up a base station at Shark Point in Ugak Bay.  You have most likely heard of the Global Positioning System, and you may know that GPS works by identifying your location on Earth’s surface relative to the known locations of satellites in orbit.  (For a great, kid-friendly explanation of GPS, I encourage students to check out this website.)  But what happens if the satellites aren’t quite where we think they are?  That’s where a base station, or ground station, becomes useful. Base stations, like the temporary one that we installed at Shark Point, are designed to improve the precision of positioning data, including the data used in the ship’s daily survey operations.

power source for the base station
Setting up the power source for the base station

Setting up the Base Station involved several steps.  First, a crew of six people were carried on RA-7, the ship’s small skiff, to the safest sandy area near Shark Point. It was a wet and windy trip over on the boat, but that was only the beginning! Then, we carried the gear we needed, including two tripods, two antennae (one FreeWave antenna to connect with the ship and a Trimble GPS antenna), a few flexible solar panels, two car batteries, a computer, and tools, through the brush and brambles and up as close to the benchmark as we could reasonably get.  A benchmark is a physical marker (in this case, a small bronze disk) installed in a location with a known elevation above mean sea level. For more information about the different kinds of survey markers, click here.

Base station installers
Base station installers: damp, but not discouraged

Next we laid out a tarp, set up the antennae on their tripods, and hooked them up to their temporary power source.  After ensuring that both antennae could communicate, one with the ship and the other with the satellites, we met back up with the boat to return to the ship.  The base station that we set up will be retrieved in about a week, once it has served its purpose.


Career Focus – Commanding Officer (CO), NOAA Corps

CO Ben Evans at dinner
CO Ben Evans enjoying dinner with the other NOAA Corps officers

Meet Ben Evans.  As the Commanding Officer of NOAA Ship Rainier, he is the leader, responsible for everything that takes place on board the ship as well as on the survey launches. Evans’ first responsibility is to the safety of the ship and its crew, ensuring that people are taking the appropriate steps to reduce the risks associated with working at sea.  He also spends a good deal of his time teaching younger members of the crew, strategizing with the other officers the technical details of the mission, and interpreting survey data for presentation to the regional office.

Evans grew up in upstate New York on Lake Ontario.  He knew that he wanted to work with water, but was unsure of what direction that might take him.  At Williams College he majored in Physics and then continued his education at Woods Hole Oceanographic Institution, completing their 3-year Engineering Degree Program.  While at WHOI, he learned about the NOAA Commissioned Officers Corps, and decided to apply.  After four months of training, he received his first assignment as a Junior Officer aboard NOAA Ship Rude surveying the waters of the Northeast and Mid-Atlantic.  Nearly two decades later, he is the Commanding Officer of his own ship in the fleet.

When asked what his favorite part of the job is, Evans smiled to himself and took a moment to reply.  He then described the fulfillment that comes with knowing that he is a small piece of an extensive, ongoing project–a hydrographic tradition that began back in 1807 with the United States Survey of the Coast.  He enjoys working with the young crew members of the ship, sharing in their successes and watching them grow so that together they may carry that tradition on into the future.

Danielle Koushel, NOAA Corps Junior Officer
Danielle Koushel, NOAA Corps Junior Officer, tracks our location on the chart


Personal Log

For my last post, I would like to talk about some of the amazing marine life that I have seen on this trip.  Seals, sea lions, and sea otters have shown themselves, sometimes in surprising places like the shipyard back in Seward.  Humpback whales escorted us almost daily on the way to and from our small boat survey near Ugak Bay. One day, bald eagles held a meeting on the beach of Ugak Island, four of them standing in a circle on the sand, as two others flew overhead, perhaps flying out for coffee.  Even the kelp, as dull as it might seem to some of my readers, undulated mysteriously at the surface of the water, reminding me of alien trees in a science fiction story.

Shark Point
Looking out over Shark Point from the base station

Stepping up onto dry land beneath Shark Point, we were dreading (yet also hoping for) an encounter with the great Kodiak brown bear. Instead of bears, we saw a surprising number of spring flowers, dotting the slopes in clumps of blue, purple, and pink. I am sensitive to the smells of a new place, and the heady aroma of green things mixed with the salty ocean spray made our cold, wet trek a pleasure for me.  


Word of the Day

Davit – a crane-like device used to move boats and other equipment on a ship


Speaking of Refraction…

Rainbow
Rainbows are caused by the refraction of light through the lower atmosphere

Thank you to NOAA Ship Rainier, the Teacher at Sea Program, and all of the other people who made this adventure possible.  This was an experience that I will never forget, and I cannot wait to share it with my students back in Georgia!

Jill Bartolotta: Sounds of the Deep, June 5, 2019

NOAA Teacher at Sea

Jill Bartolotta

Aboard NOAA Ship Okeanos Explorer

May 30 – June 14, 2019

Mission:  Mapping/Exploring the U.S. Southeastern Continental Margin and Blake Plateau

Geographic Area of Cruise: U.S. Southeastern Continental Margin, Blake Plateau

Date: June 5, 2019

Weather Data:

Latitude: 29°01.5’ N

Longitude: 079°16.0’ W

Wave Height: 2 feet

Wind Speed: 10 knots

Wind Direction: 128

Visibility: 10 nm

Air Temperature: 27.7°C

Barometric Pressure: 1021.3

Sky: few

Science and Technology Log

What is sonar?

Sonar is the use of sound to describe the marine environment. Sonar can be compared to satellites that use light to provide information about Earth, but instead of light, sound is used. It is used to develop nautical charts, detect hazards under the water, find shipwrecks, learn about characteristics of the water column such as biomass, and map the ocean floor. There are two types of sonar, active and passive. Active sonar is sonar that sends out its own sound wave. The sonar sends a sound wave (ping) out into the water and then waits for the sound to return. The return sound signal is called an echo. By assessing the time, angle, and strength of the return sound wave or echo one can learn many details about the marine environment. Passive sonar does not actively send out a sound ping, but rather listens for the sound from other objects or organisms in the water. These objects may be other vessels and these organisms may be whales or marine ecosystems such as coral reefs.

Sound waves move through the water at different speeds. These speeds are known as frequencies and the unit of measurement for sound is a hertz (Hz). Lower frequencies (example 18 kHz) are able to go farther down because they move slower and have more power behind them. It is like when a car goes down your street, pumping the bass (always seems to happen when I am trying to sleep) and you can hear it for a long time. That is because it is a low frequency and has longer wave lengths. Higher frequencies (example 200 kHz) move faster, but have less power. The sound waves should reach the bottom, an object, or biomass in the water column, but there may be no return or echo. High frequency sound waves are closer together. High frequencies give you a good image of what is happening near the surface of the water column and low frequencies give you a good idea of what is happening near, on, or under the ocean floor.

Type of Sonar on Okeanos Explorer

There are many types of sonar and other equipment aboard Okeanos Explorer for use during mapping operations. All have different capabilities and purposes. Together they provide a complete sound image of what is happening below us.

Kongsberg EM302 Multibeam Sonar

Multibeam sonar sends sound out into the water in a fan pattern below the hull (bottom) of the ship. It is able to map broad areas of the water column and seafloor from depths of 10 meters to 7,000 meters. Only the deepest trenches are out of its reach. It is the most appropriate sonar system to map seafloor features such as canyons and seamounts. The fan like beam it emits is 3-5.5x the water depth with a max swath range of 8 km. However, when you get to its depths below 5,000 meters the quality of the sound return is poor so scientists keep the swath range narrower to provide a higher quality of data return. The widest swath area scientists can use while maintaining quality is a depth of 3,300-5,000 meters. The user interface uses a color gradient to show you seafloor features (red=shallow and purple=deep).

Swath ranges for the multibeam sona
Swath ranges for the multibeam sonar at various depths. The y-axis shows the water depth in meters and the x-axis shows the swath width in meters. Photo credit: SST Charlie Wilkins, NOAA Ship Okeanos Explorer
Multibeam Sonar information
Some of the information that is collected using the multibeam sonar with labels describing their purpose. Photo Credit: NOAA OER

Backscatter

Backscatter uses the same pings from the multibeam. People use backscatter to model or predict physical or biological properties and composition of the sea floor. The coloring typically is in grayscale. A stronger echo looks brighter in the image. A weaker echo looks darker in the image. It gives you a birds-eye view of seafloor characteristics such as substrate density and seafloor features.

Backscatter and Bathymetry
Top image is backscatter showing you a birds-eye view of the ocean floor. The bottom image shows you what it looks like when backscatter is overlaid over the bathymetry layer. You are able to see intensity of the sound return, but floor features are more noticeable. Photo credit: NOAA OER

XBT

An Expendable Bathy-Thermograph (XBT) provides you with information on the temperature gradients within the water. When the temperature profile is applied to a salinity profile (taken from World Ocean Atlas) you are able to determine sound velocity or the rate at which the sound waves can travel through the water. When sound moves through water it does not move in a straight line. Its path is affected by density which is determined by water type (freshwater or saltwater) and temperature. Freshwater is less dense than saltwater and cold water is denser than warm water. The XBT information accounts for sound refraction (bending) through various water densities. When near shore XBTs are launched more frequently because the freshwater inputs from land alter density of the water and temperatures in the water column are more varied. XBTs are launched less frequently when farther from shore since freshwater inputs are reduced or nonexistent and the water column temperature is more stable. However, ocean currents such as the Gulf Stream (affecting us on this cruise) can affect density as well. The Gulf Stream brings warm water from the Gulf of Mexico around the tip of Florida and along the eastern coast of the United States. Therefore, one must also take into account which ocean currents are present in the region when determining the launch schedule of XBTs.

Loading the XBT Launcher
Senior Survey Technician Charlie Wilkins and Explorer in Training, Jahnelle Howe, loading the XBT launcher. XBTs are launched off the stern of the ship.
XBT Capture
Sound speed or velocity is determined by the density of the water, which is determined by temperature and salinity. Focus on the blue line in each graph. The first graph takes the information from the temperature and salinity graphs to determine sound speed. If we look at the first graph, we see that sound speed slows with depth. Sound speed slows because according to the second graph the temperature is colder making the water denser, thus affecting sound speed. Salinity does not vary much according to the third graph so its effect on density is most likely limited. Photo credit: NOAA OER

Simrad EK60 and EK80 Split-beam Sonar

Split-beam sonar sends out sound in single beam of sound (not a fan like the multibeam). Each transducer sends out its own frequency (example 18 kHz, 38 kHz, 70 KHz, 120 kHz, and 200 kHz). Some frequencies are run at the same time during mapping operations. Mapping operations typically do not use the 38 kHz frequency since it interferes with the multibeam sonar. Data collected with the use of the EK60 or EK80 provides information about the water column such as gaseous seeps, schools of fish, and other types of dense organism communities such as zooplankton. If you remember my “did you know” from the second blog, I discussed how sonar can be used to show the vertical diurnal migration of organisms. Well the EK60 or EK80 is the equipment that allows us to see these biological water column communities and their movements.

Water column information
Water column information collected with the EK60 or EK80 split beam sonar. If you look at the first row you can see, in the image to the left, the blue dots are at the top and in the second image the blue dots are moving back down into the water column as the sun rises. The process of organisms’ movement in the water column at night to feed is known as vertical diurnal migration. Photo Credit: NOAA OER

Knudsen 3260 Sub-bottom Profiler

The purpose of using a sub-bottom profiler is to learn more about the layers (up to 80 meters) below the ocean floor. It works in conjunction with the sonar mapping the ocean floor to provide more information about the bottom substrate, such as sediment type and topography features. Sub-bottom data is used by geologists to better understand the top layers of the ocean floor. A very low frequency is used (3.5 kHz) because it needs to penetrate the ocean sediment. It will give you a cross section of the sea floor so floor features can be detected.

Cross section of the ocean seafloor
Cross section of the ocean seafloor shows you substrate characteristics. Photo Credit: NOAA OER

Telepresence

Telepresence aboard the ship allows the science team to get mapping products and raw data to land on a daily basis. The science team can also live feed data collection to shore in real time. By allowing a land based shore team to see the data in real time you are adding another system of checks and balances. It is one more set of eyes to make sure the data being collected looks correct and there are no issues. It also allows a more collaborative approach to mapping, since you are able to involve a worldwide audience in the mission. Public viewers can tune in as well.  Support for the technology needed to allow telepresence capabilities comes in partnership with the Global Foundation of Ocean Exploration (GFOE). With GFOE’s help, the protocols, high-speed satellite networks, Internet services, web and social media interfaces, and many other tools are accessible when out to sea. The NOAA Office of Exploration and Research (OER) provides the experts needed to develop, maintain, and operate the telepresence systems while at sea, but also at shore through the Exploration Command Centers (ECCs) and the University of Rhode Island’s Inner Space Center.

Live interaction
Live interaction with Okeanos Explorer, Inner Space Center at URI/GSO, and a group of high school students. Photo credit: NOAA OER

All in all, the equipment aboard Okeanos Explorer is impressive in its abilities to provide the science team with a high quality and accurate depiction of the ocean floor and water column. The science team aboard is able to interpret the data, clean out unwanted data points, store massive data files on computers, and send it back to land daily, all while rocking away at sea. Very impressive and very cool!

Personal Log

I learned all about memes today. Apparently they are very popular on the ship. So popular, we are even in the middle of a meme contest. For those of you unfamiliar to memes like I was, a meme is a funny picture with a clever caption that makes you laugh or relates to something in your life. After my tutorial in meme making, we had a great time out on the bow of the ship playing corn hole and hanging out. The night was beautiful. The humidity subsided and there was a great breeze. After the sun set, I watched the stars come out and then went inside to learn more about the mapping process. I am starting to get a better understanding of what the science team is doing. You know the how and the why of it all. After I couldn’t keep my eyes open any longer, I made my nightly venture out onto the bow to look from some bioluminescence, the glittering of zooplankton in the night. A magical site. I will leave you wondering how the ocean glitters until one of my future blogs when I describe the process of bioluminescence.

Corn hole
General Vessel Assistant Sidney Dunn (left) and General Vessel Assistant Christian Lebron (right) playing corn hole on the bow at sunset.

Did You Know?

The SOFAR (Sound Fixing and Ranging) channel occurs in the world’s oceans between depths of 800 to 1000 meters in the water column. Because of the density and pressure around this channel, sound waves travel for an extended distance. It is thought that fin whales travel to this channel to communicate with other fin whales many kilometers away.

Jill Bartolotta: All Aboard, Shipping Out, May 30, 2019

NOAA Teacher at Sea

Jill Bartolotta

Aboard NOAA Ship Okeanos Explorer

May 30 – June 14, 2019

 

Mission:  Mapping/Exploring the U.S. Southeastern Continental Margin and Blake Plateau

Geographic Area of Cruise: U.S. Southeastern Continental Margin, Blake Plateau

Date: May 30, 2019

Weather Data:

Latitude: 24° 47.7 ‘N
Longitude: 080° 20.2’W
Wave Height: 2-3 feet
Wind Speed: 10 knots
Wind Direction: 114
Visibility: 10 nm
Air Temperature: 28.2°C
Barometric Pressure: 1013.5 mb
Sky: Few clouds

 

Science Log

Today we depart Key West. The days in port have been spent readying equipment, training mission crew, and exploring the beauty that is Key West. We say our final goodbyes to terra firma and head out to sea.

Ship sign board showing departure date
Departure time!
NOAA Ship Okeanos Explorer
Home for the next two weeks.

The ship we are aboard, NOAA Ship Okeanos Explorer, is managed by NOAA’s Office of Marine and Aviation Operations. The NOAA Commissioned Officer Corps commands and operates the ship in combination with wage mariners. Equipment on board is managed by NOAA’s Office of Exploration and Research (OER) in collaboration with the Global Foundation for Ocean Exploration.

If you visit OER’s website, you will see in their mission that they are the “only federal organization dedicated to ocean exploration. By using unique capabilities in terms of personnel, technology, infrastructure, and exploration missions, OER is reducing unknowns in deep-ocean areas and providing high-value environmental intelligence needed by NOAA and the nation to address both current and emerging science and management needs.” The purpose of OER is to explore the ocean, collect data, and make this data publicly available for research, education, ocean management, resource management, and decision-making purposes.

One of OER’s priorities is to map the US Exclusive Economic Zone (EEZ) at depths of 200 meters or greater. This is some deep stuff. The EEZ distance from shore is dependent on a variety of factors such as proximity to territorial waters of other countries and the continental shelf. If you want to learn more about how EEZs are established visit the United Nations Oceans and the Law of the Sea Website https://www.un.org/en/sections/issues-depth/oceans-and-law-sea/. Within the EEZ a country has exclusive rights to various activities such as fishing, drilling, ocean exploration, conservation, and resource management.

Map of U.S. Exclusive Economic Zone
Exclusive Economic Zone (EEZ) for the United States. We are mapping in the Southeast Region (lime green). Photo Credit: NOAA

We are currently en route to our mapping area so we can map previously unmapped areas. The mapping that will occur on this mission will be used to help inform dive locations for the ROV (Remotely Operated Vehicle) mission that will take place after our mission. Mapping allows us to understand sea floor characteristics and learn more about deep sea ecosystems that can be later explored with an ROV. An ecosystem of interest for this mapping mission is deep sea coral habitat. The area where we will be mapping is thought to be the largest deep sea coral habitat in US waters and it is largely unmapped. As data is collected, it is cleaned (more on this at a later time) of noise (unwanted data points). Products such as multi-beam geospatial layers are made available to end users on land roughly 24 hours after data is collected. End users could include other researchers, educators, ocean policy and management decision-makers, and more specifically those who will be joining the ROV mission happening in two weeks.

If you want to follow Okeanos Explorer and her crew on our mission, see the live feed available through this link https://oceanexplorer.noaa.gov/livestreams/welcome.html.

Personal Log

We have just left port. The dolphins are jumping, the sea is the most perfect turquoise blue, and the wind blows on our sun-kissed faces. I have left port many times on my various trips, but today was magical. I think what makes this departure from port so magical is the journey that lies ahead. I am nervous and excited all at the same time. It is slowly settling in that I am able to participate in this once in a lifetime experience. Never in my wildest dreams did I think I would be aboard an ocean exploration vessel. Wow! Just Wow!

View of Key West from shore
Fondest farewell Key West.

So far everything is good. Dabbled pretty hard in the seasickness world today. I tried to get on my computer too early and it went down swell from there. However, some wind on my face, ginger soup, and bubbly water made everything better. Many people have told me it is important to embark on a task to get my mind off feeling unwell. I have taken this to heart and have been meeting all the wonderful people on the ship, learning more about them and their role on the ship. In the coming two weeks, I plan on learning about every facet that it takes to operate an exploration mission. From what makes the ship move forward to the detailed intricacies of mapping the sea floor to those who make it all possible.

I hope I will be able to share my experience with you so it feels like you are with me on the ship. Using words and pictures I will try to make you feel as if you are aboard with all of us. I will do my best to show you the blue hues we encountered today and explain what it is like to be out to sea with land many miles away. But I still encourage you all to try it for yourself. Words and images will only give you half the story. You need to feel the rest firsthand.

Blue water out of Key West
Bluest of blues. Words and images fail me here. The blue hues we saw today are the most spectacular colors I have ever seen.

Sunset is upon the horizon so I leave you for now. Stay tuned for more about our grand adventure.

Sun sets over the ocean
First sunset at sea

Did You Know?

You can use sonar to learn more about the organisms living in the water column. For example, sonar has the ability to show you the migration of zooplankton and their predators to the surface at night and back down when the sun rises. This phenomenon is called vertical diurnal migration.

Ship Words

Different terms are used to describe items, locations, or parts of the ship. As I learn new words I would like to share my new vocabulary with all of you. If there is a ship term you want to know more about let me know and I will find out!

Port: Left side of ship

Starboard: Right side of ship

Bow: Front of ship

Stern: Back of ship

Mess Deck: Where we eat

Head: Restroom

Scuttlebutt: Water fountain (and gossip)

Bulkhead: Walls

Overhead: Ceilings

Deck: Floor

Rack: Bed

Aft: Towards the back of the ship

Forward: Towards the front of the ship

Animals Seen Today

One dolphin

Hundreds of flying fish

Dozens of various seabirds

David Tourtellot: A Musical Perspective of Sonar, July 24, 2018

NOAA Teacher at Sea

David Tourtellot

Aboard NOAA Ship Thomas Jefferson

July 9-26, 2018

Mission:  Hydrographic Survey – Approaches to Houston

Geographic Area of Cruise: Gulf of Mexico

Date: July 24th, 2018

Weather Data from the Bridge

Latitude: 29°09.1270’N

Longitude: 093°46.5544’W

Visibility: 5 Nautical Miles

Sky Condition: 8/8

Wind: Direction: 70.1°, Speed: 13.3 knots

Temperature:

Seawater: 29.24°C

Air: Dry bulb:26.9°C          Wet bulb: 24.7°C

 

Science and Technology Log

Coming to NOAA Ship Thomas Jefferson, I was eager to learn all I could about sonar. I am amazed that we have the ability to explore the ocean floor using sound.

uncharted wreck
An uncharted wreck discovered by NOAA Ship Thomas Jefferson

Over the course of my previous blog entries, I have described the tools and processes used to survey using sonar. This time, I am going to try to frame the sounds that the sonars are using in a musical context, in the hope that doing so will help students (and myself) better understand the underlying concepts.

Note – many aspects of music are not standardized. For the purpose of this blog post, all musical tuning will be in equal temperament, at A=440. When I reference the range of a piano, I will be referencing a standard 88-key instrument. Many of the sonar frequencies do not correspond exactly to an in-tune pitch, so they have been written to the nearest pitch, with a comment regarding if the true frequency is higher or lower than the one written.

In sonar and in music, when considering soundwaves it is important to know their frequency, a measure of how many waves occur over the course of a set period of time. Frequency is measured in a unit called Hertz (abbreviated as Hz), which measures how many soundwaves occur in one second. One Hertz is equal to one soundwave per second. For example, if you heard a sound with a frequency of 100Hz, your ears would be detecting 100 soundwaves every second. Musicians also are concerned with frequency, but will use another name for it: pitch. These words are synonymous – sounds that are higher in pitch are higher in frequency, and sounds that are lower in pitch are lower in frequency.

Below are the eight octaves of the note A that are found on a piano, each labeled with their frequency. The notes’ frequencies have an exponential relationship – as you move from low to high by octave, each note has a frequency that is double that of its predecessor.

Piano As with frequencies
The frequency of each A on a piano

The highest note on a piano, C, has a frequency of 4186.01Hz

Highest Note on a piano
The frequency of the highest note on a piano

Average, healthy young humans hear sounds ranging from 20Hz to 20,000Hz. All sounds outside of that range are inaudible to people, but otherwise no different from sounds that fall within the human range of hearing. The highest note we would be able to hear would be an E♭, at a frequency of 19,912.16Hz (a frequency of exactly 20,000Hz would fall in between E♭ and E♮, though would be closer to E♭). If put on a musical staff, it would look like this:

High Eb 19kHz
The frequency of the highest note in the human range of hearing

The hull of NOAA Ship Thomas Jefferson is equipped with several sonar transmitters and receivers, which can operate at a wide variety of frequencies.

TJ Sonar
The hull of NOAA Ship Thomas Jefferson, with several sonars. Note that the projectors that transmit lower frequencies are larger than the ones that transmit higher frequencies. This is similar to musical instruments – instruments that make lower sounds, like the tuba or the double bass, are larger than instruments that make higher sounds, like the trumpet or the violin

Higher frequencies provide higher resolution returns for the sonar, but they dissipate more quickly as they travel through water than lower frequencies do. Surveyors assess the depth of the water they are surveying, and choose the frequency that will give them the best return based on their conditions. Most of the sonar frequencies are too high for humans to hear. The ship’s multi-beam echo sounder has a variable frequency range of 200,000Hz-400,000Hz, though as I’ve been on board they’ve been scanning with it at 300,000Hz. Likewise, the multi-beam sonars on the launches have also been running at 300,000Hz. The ship has a sub-bottom profiler, which is a sonar used for surveying beneath the seafloor. It operates at a frequency of 12,000Hz, and has the distinction of being the only sonar on the ship that is audible to humans, however, we have not had a need to use it during my time aboard the Thomas Jefferson.

The ship’s side scan towfish (which I described in my previous blog entry) operates at 455,000Hz.

Here, we can see what those frequencies would look like if they were to be put on a musical staff.

Assorted Sonars and reference pitches
The frequencies of sonar, with reference pitches

Altering the frequency isn’t the only way to affect the quality of the reading which the sonar is getting. Surveyors can also change the pulse of the sonar. The pulse is the duration of the ping. To think about it in musical terms, changing the pulse would be akin to switching from playing quarter notes to playing half notes, while keeping the tempo and pitch the same. Different sonar pulses yield different readings. Shorter pulses provide higher resolution, but like higher frequency pings, dissipate faster in water, whereas longer pulses provide lower resolution, but can reach greater depths.

Personal Log

Mariners have a reputation for being a rather superstitious bunch, so I decided to ask around to see if that held true for the crew of the Thomas Jefferson. Overall, I found that most didn’t strictly adhere to any, but they were happy to share some of their favorites.

Everyone I spoke to told me that it is considered bad luck to leave port on a Friday, though the Commanding Officer, CDR Chris van Westendorp, assured me that you could counteract that bad luck by making three 360° turns to the left as soon as the ship is able. Many on the crew are also avid fishermen, and told me that bringing bananas aboard would lead to a bad catch, and one went so far as to be mistrustful of yellow lighters as well.

Certain tattoos are said to bring good luck – I was told that sailors often have a chicken and a pig tattooed on their feet. According to custom, those animals were often stored in wooden crates that would float if a ship went down, and having them tattooed onto you would afford you the same benefit. When asked if he was superstitious one of our helmsmen Jim proudly showed me a tattoo he has of a dolphin. He explained that having a sea creature tattooed on your body would prevent drowning. “It works!” he said with a grin, “I’ve never drowned!”

Several maritime superstitions deal with foul weather. Umbrellas are said to cause bad weather, as is split pea soup. Whistling while on the bridge is said to “whistle in the winds.” While not a superstition per se, many crew members told me variations of the same meteorological mantra: Red sky at night, sailor’s delight. Red sky in the morning, sailors take warning.

One of the NOAA Corps Officers aboard, ENS Garrison Grant, knew several old superstitions related to shipbuilding. When laying the keel (the first piece of the ship to be put into place), shipbuilders would scatter evergreen boughs and tie red ribbons around it to ward off witches. Historically, having women aboard was considered bad luck, though, conversely it was said that if they showed their bare breasts to a storm, it would subside. This is why several ancient ships had topless women carved into the masthead. Legend has it that in order to assure that a ship would float, when it was ready to be launched for the first time, virgins would be tied to the rails that guided the ship from the ship yard into the water. The weight of the ship would crush them, and their blood would act as a lubricant, allowing the ship to slide into the water for the first time. Yikes! Thankfully, as society became more civilized, this practice evolved into the custom of breaking a bottle of champagne against a ship’s bow!

Did you know? Musical instruments play an important role in ship safety! In accordance with maritime law, ships will use auditory cues to make other vessels aware of their presence in heavy fog. For large ships, this includes the ringing of a gong at regular intervals.

Latest Highlight: During this week’s fire drill, I got to try the fire hose. It was very powerful and a lot of fun!

David Tourtellot during a fire drill
David Tourtellot during a fire drill

David Tourtellot: The Speed of Sound, July 15, 2018

NOAA Teacher at Sea

David Tourtellot

Aboard NOAA Ship Thomas Jefferson

July 9-26, 2018

Mission:  Hydrographic Survey – Approaches to Houston

Geographic Area of Cruise: Gulf of Mexico

Date: July 15th, 2018

Weather Data from the Bridge

Latitude: 28° 49.4115’N

Longitude: 93° 37.4893’W

Visibility: 10+ Nautical Miles

Sky Condition: 4/8

Wind: Direction: 240°, Speed: 7 knots

Temperature:

Seawater: 31.7°C

Air: Dry bulb:31.5°C          Wet bulb: 27.5°C

 

Science and Technology Log

 

NOAA Ship Thomas Jefferson is well underway in its mission of surveying the seafloor. The primary tool that the ship (as well as its 2 Hydrographic Survey Launches) is using to accomplish this task is sonar. Sonar was originally an acronym for SOund Navigation And Ranging. If you are familiar with echolocation – the system that some animals (such as bats and dolphins) use to navigate their surroundings – then you already have a basic understanding of how sonar works. The sonar transmits a short sound (called a ping) that will travel down, away from the ship, until it hits the seafloor. At this point, it will reflect off of the sea floor, and echo back up to the ship, where it is detected by the sonar’s receiver. The crew aboard are then able to calculate the depth of the water.

To make the necessary calculations, there are 3 variables at play: the time that it takes for the ping to travel; the distance that the ping travels; and the velocity, or the speed, at which the ping moves through the water. If we know two of those variables, it is easy to calculate the third.

When using sonar to determine the depth of the water, distance is the unknown variable – that’s what we’re ultimately trying to figure out. To do so, we need to know the other two variables. Time is an easy variable for the sonar to measure. The sonar has a transmitter, which generates the ping, and a receiver, which hears it. These two components communicate with one another to give us an accurate measure of time. The third variable, velocity, is a bit trickier.

In saltwater, sound travels approximately 1500 meters per second. However, that rate can vary slightly based on water conditions such as temperature and salinity (how salty the water is). In order for sonar to get as accurate a reading as possible, it needs to calculate the precise speed of sound for the particular water it is in at the moment. The sonar is able to do that by using a component called a sound velocity sensor, known colloquially as a singaround.

Sonar 1 Singaround
The sonar on the hull of one of the Hydrographic Survey Launches. The orange rectangles are the projector (or, the transmitter) and the receiver, and the component in the green circle is the singaround

A singaround looks like a bar with a nub on each end. One nub is a projector, and the other is a reflector. The projector broadcasts a ping that travels parallel to the hull of the ship, bounces off of the reflector, and returns to the projector. We use that information to calculate velocity. The calculation uses the same 3 variables as above (time, distance, and velocity), but this time, distance isn’t the unknown variable anymore – we know exactly how far the ping has traveled, because we know how far the projector and reflector are from one another. The singaround electronically measures how long it takes for the ping to travel, and since we now know two of the variables (distance and time) we can calculate the third (velocity) for our particular water conditions at the face of the sonar.

Sound travels roughly 4 times faster in water than it does in air (this is because water is denser than air). To ensure that the sonar gets an accurate reading, it is important that air bubbles don’t get in the way. The boat’s hull (bottom) has a triangular metal plate directly in front of the sonar, which routes air bubbles around to the side of the sonar.

Sonar 2
The hull of one of the Hydrographic Survey Launches.

 

Personal Log

Each day, the ship’s CO (Commanding Officer) publishes a POD, or Plan Of the Day. This is full of important information – it tells us what the ship will be doing; if/when we will deploy the launch boats, and who will be on them; what time meals will be; and the expected weather conditions. Below is an example from Friday, July 13th.

Plan of the Day
NOAA Ship Thomas Jefferson Plan of the Day for Friday, July 13, 2018

On Friday, I had the opportunity to go out on one of the Hydrographic Survey Launches. Because of their smaller size, the launch boats are great for surveying difficult to maneuver areas. For instance, we spent most of the day surveying an area near an oil rig, and were able to get much closer than the Thomas Jefferson could.

Mike Below Deck
Survey Tech Mike Hewlett collecting and analyzing survey data aboard a launch boat

Oil Rig and Boat
An oil rig and a supply vessel

I’ve been very impressed by how multi-talented everyone on the ship seems to be. In addition to analyzing data, the ship’s survey techs can also be found handling lines as the survey boats are launched and recovered, and do a lot of troubleshooting of the hardware and software they’re using. The coxswains (people who drive small boats) double as engineers, fixing issues on the launch vessels when away from the ship. I’m surrounded by some very gifted people!

Fixing the AC
Coxswain Francine Grains and Survey Tech Brennan Walters fixing the air conditioner on one of the launch boats that had stopped working unexpectedly. They had it up and running in no time

Did you know?: As president, Thomas Jefferson ordered the first survey of the coastline of the United States. Because of this, NOAA Ship Thomas Jefferson is named for him. 

Latest Highlight: While surveying, we spotted a water spout in the distance. A water spout is a tornado that forms over water. Luckily, we were a safe distance away. It was an amazing sight to see!

 

Brandy Hill: What Lies Beneath the Surface, July 1, 2018

NOAA Teacher at Sea

Brandy Hill

Aboard NOAA ship Thomas Jefferson

June 25, 2018 –  July 6, 2018

 

Mission: Hydrographic Survey- Approaches to Houston

Geographic Area of Cruise: Gulf of Mexico

Date: July 1, 2018

 

Weather Data from the Bridge

Latitude: 29° 10.1’ N

Longitude: 093° 54.5’ W

Visibility: 10+ NM

Sky Condition: 3/8

Wind: 16 kts

Temperature:

Sea Water: 29.4° C

Air: 27° C

 

Science and Technology Log

At this point I have been able to understand more of the sonar technology taking place during the survey aboard the Thomas Jefferson. The ship uses two types of sonar: multibeam and side scan. Both work together transmitting and receiving sound pulses to and from the ocean floor. This provides a multispectral analysis.

Julia Wallace, a physical scientist, works at the sonar acquisition station. This requires a large amount of multitasking as she communicates with the bridge (ship steering deck), watches the safety cameras, and makes sure both sonar devices are working correctly.
Julia Wallace, a physical scientist, works at the sonar acquisition station. This requires a large amount of multitasking as she communicates with the bridge (ship steering deck), watches the safety cameras, and makes sure both sonar devices are working correctly.

Multibeam sonar is located underneath the hull of the ship. Multibeam is used to detect bathymetry (the depth of the ocean floor). Multibeam backscatter (reflected wave energy) gives a reading of the surface intensity. For example, a strong signal would mean a harder surface like rock or pipeline. With multibeam sonar, you can also adjust the sound wave frequency. For example, high frequency (primarily used during this survey in the Gulf of Mexico) is used for shallower waters allowing for higher resolution images. Images from multibeam have a color gradient to allow for clear vision of contours and depth differences. One way surveyors aboard the TJ may use backscatter images is to determine areas where bottom sampling might be applicable.

A NOAA ship using mulitbeam sonar. (Courtesy of NOAA)
A NOAA ship using mulitbeam sonar. (Courtesy of NOAA)

Bathymetry acquired using multibeam echosounder layered over a nautical chart.  Blue and green wave lengths penetrate further in water, so the coloring corresponds to this observation. This poster is from a previous Thomas Jefferson hydrographic survey near Savannah, Georgia. (Prepared by CHST Allison Stone)
Bathymetry acquired using multibeam echosounder layered over a nautical chart.  Blue and green wave lengths penetrate further in water, so the coloring corresponds to this observation. This poster is from a previous Thomas Jefferson hydrographic survey near Savannah, Georgia. (Prepared by CHST Allison Stone)

3D bathymetry imagery from the Okeanos Explorer. (NOAA)
3D bathymetry imagery from the Okeanos Explorer. (NOAA)

A close-up view of multibeam data. The third window down shows multibeam backscatter.
A close-up view of multibeam data. The third window down shows multibeam backscatter.

The side scan sonar is used alongside multibeam to provide black and white scans of images. Like multibeam backscatter, side scan measures the intensity of the sound returning from the sea floor. For example, a side scan return with high intensity could indicate a difference in material like pipeline or a wreck. A low intensity value could mean that the side scan sonar waves have reached a muddy substrate. Julia used the analogy of a tennis ball being bounced against a wall of different materials. For example, the tennis ball hitting a concrete wall would bounce back with higher intensity than one being bounced against a soft wall. Side scan sonar is very effective at detecting features that protrude off the sea floor, and for shallow water surveys, typically can see farther and cover a greater area the sea floor than multibeam echosounders alone.

The side scan sonar sensor is located on a torpedo-shaped “towfish” and pulled behind the boat. When viewing side scan images, surveyors typically look for the acoustic shadow cast by a feature protruding off the sea floor. By measuring the length of the acoustic shadow, hydrographers can determine whether the feature requires additional investigation. For example, the outline of a shipwreck, bicycle, or pipeline. However, it can also detect mammals like dolphins or schools of fish.

Diagram of side scan sonar. (Courtesy of thunder bay 2001, Institute for Exploration, NOAA-OER)
Diagram of side scan sonar. (Courtesy of thunder bay 2001, Institute for Exploration, NOAA-OER)

The Thomas Jefferson sidescan sonar on deck.
The Thomas Jefferson sidescan sonar on deck.

In the early morning, the sidescan sonar picked up the image of an incorrectly charted shipwreck. Height is estimated using the "shadow" of the wreck.
In the early morning, the sidescan sonar picked up the image of an incorrectly charted shipwreck. Height is estimated using the “shadow” of the wreck.

Sidescan sonar imagery layered on a nautical chart. It is important to remember that sidescan data does not account for depth, it is a measure of differences in sea floor substrate.
Sidescan sonar imagery layered on a nautical chart. It is important to remember that sidescan data does not account for depth, it is a measure of differences in sea floor substrate.

Look closely and you can see arc lines in the sidescan imagery. Lt. Anthony Klemm explains that these arcs are from ships dragging anchor and stirring up the sea floor.
Look closely and you can see arc lines in the sidescan imagery. Lt. Anthony Klemm explains that these arcs are from ships dragging anchor and stirring up the sea floor.

While this is happening, surveyors are also towing a MVP or Moving Vessel Profiler to capture information about the water column. This is important because multiple factors in the water column need to be corrected in order for accurate sonar calculations. For example, the speed of sound in salt water is roughly 1500 m/s but may change while the ship is traveling over different parts of the sea floor or passing through a thermocline (steep temperature gradient) or halocline (steep salinity gradient). The MVP is similar to the CTD used on the launch boat (see previous post), but the MVP allows the ship to continue moving at about 10 knots (average survey speed), while the CTD must be cast when the ship is stationary.

Information from the Moving Vessel Profiler. From left to right, the MVP tracks sound speed, temperature, and salinity in relation to depth.
Information from the Moving Vessel Profiler. From left to right, the MVP tracks sound speed, temperature, and salinity in relation to depth.

For more information on multispectral analysis and sonar, see these resources:

https://oceanexplorer.noaa.gov/explorations/09bermuda/background/multibeam/multibeam.html

https://oceanservice.noaa.gov/education/seafloor-mapping/how_sidescansonar.html

Personal Log

One of my goals in the classroom is to teach students to be comfortable making and learning from mistakes. Making mistakes in math and science is common and welcome because they lead to great discussion and future change. Often, my sixth graders get discouraged or so caught up in failure that they become paralyzed in making further attempts. While aboard the Thomas Jefferson, I have witnessed several aspects not go according to plan. I think these experiences are important to share because they provide real-life examples of professionals coming together, learning from mistakes, and moving forward.

Around 4:00 am, the towfish side scan sonar became entangled with the MVP. This was a horrendous disaster. The crew spent about 16 hours contemplating the issue and collecting data using the multibeam only, which is less than ideal.  One of XO LCDR McGovern’s many roles aboard the ship is to serve as the investigator. She reviewed tapes of the early morning, talked with the crew, and later held a debrief with all involved. When something like this happens, the ship must write a clear incident report to send to shore. There were many questions about why and how this happened as well how to best proceed. In the end, the towfish and MVP were untangled with no damage present to the sensor. Within the same day, both were cast out and back in use.

I find this to be an astounding example of perseverance and teamwork. Despite being disappointed and upset that a critical tool for collecting accurate data was in dire shape, the crew came up with a plan of action and executed. Part of the engineering and scientific processes include evaluation and redesign. Elements of the sea and a center drift of the side scan lead to a documented new plan and refiguring the process so that this is unlikely to happen again.

Lt. Charles Wisotzsky's sketch of the complications with launching both the sidescan sonar (which tends to centerline) and MVP towfish with a current coming from port side.
Lt. Charles Wisotzsky’s sketch of the complications with launching both the sidescan sonar (which tends to centerline) and MVP towfish with a current coming from port side.

This camera image captures the entanglement of the sidescan sonar and MVP.
This camera image captures the entanglement of the sidescan sonar and MVP.

Peaks

+Saw a tuna eat a flying fish

Flying Fish. (www.ocean.si.edu)
Flying Fish. (www.ocean.si.edu)

+There is a large sense of purpose on the ship. Despite complex sleep schedules to enable 24 hour operations with a smaller crew, people are generally happy and working hard.

+ There seems to be an unlimited supply of ice cream in the ice cream freezer. Junior Officer, ENS Garrison Grant introduced me to a new desert- vanilla ice cream, a scoop of crunchy peanut butter, and chocolate syrup. I also found the rainbow sprinkles.

David Amidon: Science @ Sea, June 8, 2017

NOAA Teacher at Sea

David Amidon

Aboard NOAA Ship Reuben Lasker

June 2 – 13, 2017

Mission: Pelagic Juvenile Rockfish Recruitment and Ecosystem Assessment Survey

Geographic Area of Cruise: Pacific Ocean off the California Coast

Date: June 8, 2017

 

 

 

Science and Technology Log

The main scientific research being completed on the Reuben Lasker during this voyage is the Pelagic Juvenile Rockfish Recruitment and Ecosystem Assessment Survey and it drives the overall research on the ship during this voyage. Rockfish are an important commercial fishery for the West Coast. Maintaining healthy populations are critical to maintaining the fish as a sustainable resource. The samples harvested by the crew play an important role in establishing fishery regulations. However, there is more happening than simply counting rockfish here on the ship.

How does it work? Let me try to explain it a bit.

 

First, the ship will transfer to a specific location at sea they call a “Station.”

IMG_1590
Collection stations off the California Coast that the Reuben Lasker trawls annually.

For a half hour prior to arrival, a science crew member will have been observing for Marine Mammals from the bridge area. When the station is reached, a new observer from the science crew will take over the watch outside on the deck. The fishermen on the boat crew will then unwind the net and launch it behind the boat. It must be monitored from the deck in order to ensure it is located 30 m below the surface. Once everything is set, then the ship trawls with the net at approximately 2 knots. Everything must be consistent from station to station, year to year in order to follow the standardized methods and allow the data recorded to be comparable. After the 15 minutes, then the crew pulls the net in and collects the sample from the net. This process is potentially dangerous, so safety is a priority. Science crew members can not go on the deck as they have not received the proper training.

 

 

Timelapse video of the fishermen bringing in a catch. 6/7/17 (No sound)

 

Once the sample is hauled in, the science personnel decide which method will be used to establish a representative sample. They pull out a sample that would most likely represent the whole catch in a smaller volume. Then we sort the catch by species. After completing the representative samples, they will eventually stop taking counts of the more abundant organisms, like krill. They will measure the volume of those creatures collected and extrapolate the total population collected by counting a smaller representative sample. Finally, we counted out all of the less abundant organisms, such as squid, lanternfish and, of course, rockfish. After the sample is collected and separated, Chief Scientist Sakuma collects all of the rockfish and prepares them for future investigations on shore.  

 

 

A selection of species caught off the coast of San Clemente. These include Market Squid, Anchovies, Red Crab, King-of-Salmon (the long ribbonfish), and Butterfish, among others.

NOAA has used this platform as an opportunity. Having a ship like the Reuben Lasker, and the David Starr Jordan before that, collecting the samples as it does, creates a resource for furtAher investigations. During the trawls we have catalogued many other species. Some of the species we analyzed include Sanddab, Salp, Pyrosoma, Market Squid, Pacific Hake, Octopus, Blue Lanternfish, California Headlightfish and Blacktip Squid, among others. By plotting the biodiversity and comparing the levels we recorded with the historic values from the stations, we gain information about the overall health of the ecosystem.

What happens to the organisms we collect? Not all of the catch is dumped overboard. Often, we are placing select organisms in bags as specimens that will be delivered to various labs up and down the coast.

IMG_1519
Collecting subsets for classification

This is a tremendous resource for researchers, as there is really no way for many of these groups to retrieve samples on their own. Rachel Zuercher joined the crew during this survey in part to collect samples to aid in her research for her PhD.

Along with the general species analysis, the team specifically analyzes the abundance of specific krill species. Krill forms the base of the marine ecosystems in the pelagic zone. They are a major food source for many species, from fish to whales. However, different krill species are favored by different consumers. Therefore, an extension of the Ecosystem Assessment involves determining the abundance of specific krill species. Thomas Adams has been responsible for further analyzing the krill collected. He counts out the representative sample and use microscopes to identify the species collected based on their physical characteristics.  

Additionally, at most stations a Conductivity, Temperature and Depth cast (CTD) is conducted. Basically, bottles are sent overboard and are opened at a specified depth.

IMG_1589
The apparatus for collecting water during CTD casts

Then they are collected and the contents are analyzed. Often these happen during the day prior to the Night Shift taking over, with final analysis taking place after the cruise is complete. This data is then connected with the catch numbers to further the analysis. Ken Baltz, an oceanographer on the ship, uses this information to determine the production of the phytoplankton based on the amounts of chlorophyll detected at depth. This is an important part of the food web and by adding in this component, it makes the picture below the surface clearer.

 

 

img_1488.jpg
NOAA Corps’ Ryan Belcher completing the CTD collection for a station.

Finally, there are two more scientific investigations running as we cruise the open seas during the daylight hours. Michael Pierce is a birdwatcher from the Farallon Institute for Advanced Ecosystem Research who is conducting a transect survey of Seabirds and Marine Mammals. He is based on the Flying Bridge and catalogs any birds or marine mammals that pass within 300 meters of the ship’s bow. Although difficult, this study attempts to create a standardized method for data collection of this nature. As he explained, birds are more perceptive than we are – what looks like open ocean really varies in terms of temperature, salinity and diversity below the surface. Therefore, birds tend to favor certain areas over others. These are also important components of the food web as they represent upper level predators that are not collected in the trawl net. Also, on the bottom of the ship transducers are installed that are able to gather information through the EK60 Echosounder. This sonar can accurately identify krill populations and schools of fish underwater. Again, adding the data collected from these surveys help create a much more complete understanding of the food web we are analyzing out on the open sea.

 

IMG_1591
Sonar data from the EK60

Personal Log

 

Sunday, June 4

The waves were very active all day. Boy am I glad I’m wearing the patch. There was so much wind and the waves were so high, there was a question if we were even going to send the net out. High wind and waves obviously add an element of concern, especially for the safety of the boat crew working the net.

I spent some of the day up on the Bridge- the section of the boat with all of the navigation equipment. The Executive Officer (XO) gave me an impromptu lesson about using the map for navigation. They have state-of-the-art navigation equipment, but they also run a backup completed by hand and using a compass and straightedge just like you would in math class. Of note – the Dungeness Crab season is wrapping up and many fishermen leave traps in the water to catch them. When the boat is passing through one of these areas, someone will act like a spotter so the boat can avoid getting tangled up. When I was looking with him, we saw some whale plumes in the distance.

We did launch the net twice Sunday night, collecting a TON of krill each time. In the first batch, we also caught some squid and other small prey species. The second trawl was very surprising. Despite cutting it down to a 5 minute trawl, we caught about the same amount of krill. We also caught more squid and a lot of young salmon who were probably feeding on the krill.  

IMG_1493
That is a ton of krill!

 

Monday, June 5

I am getting used to the hours now – and do not feel as guilty sleeping past 2PM considering we are up past 6 in the morning. It will make for a tricky transition back to “the real world” when I go home to NY!

During the day, spent some time just talking with the science folks and learning about the various tasks being completed. I also spent some time up on the Flying Bridge as they said they had seen some Mola, or Giant Ocean Sunfish (although I did not see them). I did have a chance to make a few videos to send to my son Aiden’s 3rd grade teacher back in NY. It did not work out as well as I had hoped, but considering we are out in the middle of the ocean, I really can’t complain about spotty wi-fi.

Once we started the night shift, we really had a good night. We completed work at 5 stations – which takes a lot of time. We saw a LOT of biodiversity last night – easily doubling if not tripling  our juvenile rockfish count. We also saw a huge variety of other juvenile fish and invertebrates over the course of the night. We finally wrapped up at 6:30 AM, what a night!

Tuesday, June 6th

We found out today that we will need to dock the ship prematurely. There is a mechanical issue that needs attention. We are en route straight through to San Diego, so no fishing tonight. However, our timing will not allow us to reach port during the day, so we will get a chance to sample the southernmost stations Wednesday night. Thus is life at sea. The science crew is staying on schedule as we, hopefully, will be back on the water this weekend.

Wednesday, June 7th

After a day travelling to San Diego, we stopped at the stations near San Clemente to collect samples. Being much farther south than before, we saw some new species – red crabs, sardines and A LOT of anchovies. Closer to shore, these counts dropped significantly and krill showed up in numbers not seen in the deeper trawl. Again, I am amazed by the differences we see in only a short distance.

 

More from our anchovy haul- the bucket contains the entire catch from our second trawl, the tray shows how we analyzed a subset. Also on the tray you find Red Crab, Salps, Mexican Lanternfish and Krill.

 

Cecelia Carroll: Visit with the NOAA Corps Officers, May 10, 2017                   

NOAA Teacher at Sea

Cecelia Carroll

Aboard NOAA Ship Henry B. Bigelow

May 2 – 13, 2017 

Mission: Spring Bottom Trawl

Geographic Area: Northeastern Atlantic

Date: May 10, 2017

Latitude: 42 54.920N
Longitude:  069 42.690
Heading:  295.1 degrees
Speed:  12.2 KT
Conditions: Clear

Science and Technology

I am on the day schedule which is from noon to midnight.  Between stations tonight is a long steam so I took the opportunity with this down time to visit the bridge where the ship is commanded.  The NOAA Corps officers supplied a brief history of the corp and showed me several of the instrument panels which showed the mapping of the ocean floor.

“The National Oceanic and Atmospheric Administration Commissioned Officer Corps, known informally as the NOAA Corps, is one of seven federal uniformed services of the United States, and operates under the National Oceanic  and Atmospheric Administration, a scientific agency within the Office of Commerce.

“The NOAA Corps is part of NOAA’s Office of Marine and Aviation Operations (OMAO) and traces its roots to the former U.S. Coast and Geodetic Survey, which dates back to 1807 and President Thomas Jefferson.”(1)

During the Civil War, many surveyors of the US Coast and Geodetic Survey stayed on as surveyors to either join with the Union Army where they were enlisted into the Army, or with the Union Navy, where they remained as civilians, in which case they could be executed as spies if captured. With the approach of World War I, President Woodrow Wilson, to avoid the situation where surveyors working with the armed forces might be captured as spies, established the U.S. Coast and Geodetic Survey Corps.

During WWI and World War II, the Corps abandoned their peacetime activities to support the war effort with their technical skills.  In 1965 the Survey Corps was transferred to the United States Environmental Science Services Administration and in 1979, (ESSA) and in 1970 the ESSA was redesignated as the National Oceanic and Atmospheric Administration and so became the NOAA Corps.

“Corps officers operate NOAA’s ships, fly aircraft, manage research projects, conduct diving operations, and serve in staff positions throughout NOAA.” (1)

“The combination of commissioned service with scientific and operational expertise allows the NOAA Corps to provide a unique and indispensable service to the nation. NOAA Corps officers enable NOAA to fulfill mission requirements, meet changing environmental concerns, take advantage of emerging technologies, and serve as environmental first responders.” (1)

There are presently 321 officers, 16 ships, and 10 aircraft.


We are steaming on a course that has been previously mapped which should allow us to drop the net in a safe area when we reach the next station.

The ship’s sonar is “painting” the ocean floor’s depth.  The dark blue is the deepest depth.

The path of the ship is highlighted.  The circles are the stations to drop the nets for a sample of the fish at that location.

This monitor shows the depth mapped against time.

This monitor also showing the depth.

A view inside the bridge at dusk.

The full moon rising behind the ship ( and a bit of cloud )

What can you do ?

  • When I asked “What can I tell my students who have an interest in NOAA ?”

If you have an interest in climate, weather, oceans, and coasts you might begin with investigating a Cooperative Observer Program, NOAA’s National Weather Service.

“More than 8,700 volunteers take observations on farms, in urban and suburban areas, National Parks, seashores, and mountaintops. The data are truly representative of where people live, work and play”.(2)

Did you know:

The NOAA Corps celebrates it 100 Year Anniversary this May 22, 2017!

Cute catch:

  1. Bobtail Squid

This bobtail squid displays beautiful colors!  (3 cm)

View from the flying bridge.

On the flying deck!


Bibliography

1. https://www.omao.noaa.gov/learn/noaa-corps/about

2. http://www.nws.noaa.gov/os/coop/what-is-coop.html

3.   http://www.history.noaa.gov/legacy/corps_roots.html

Kimberly Scantlebury: The Night Shift, May 10, 2017

NOAA Teacher at Sea

Kimberly Scantlebury

Aboard NOAA Ship Pisces

May 1-May 12, 2017

Mission: SEAMAP Reef Fish Survey

Geographic Area of Cruise: Gulf of Mexico

Date: May 10, 2017

Weather Data from the Bridge

Time: 15:36

Latitude: 2804.2177  N, Longitude: 9042.0070 W

Wind Speed: 10.2 knots, Barometric Pressure: 1016.8 hPa

Air Temperature: 26.1 C, Water Temperature: 24.89 C

Salinity: 36.49 PSU, Conditions: Some cloud, light wind, 2-4 foot waves

Science and Technology Log

Research vessels do not just work during the day. It is a 24/7 operation. Tonight I checked in with the night shift to learn more about the sonar mapping that has been done in the dark ever since I boarded NOAA Ship Pisces.

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Algebra I level math in action!

The first thing I noticed entering the dry lab was a pad of paper with math all over it. Todd, the survey technician I interviewed earlier, had noticed the the picture the ship’s sonar was producing had a curved mustache-like error in the image. Details like temperature need to be taken into account because water has different properties in different conditions that affect how sound waves and light waves move through it. He used the SOH-CAH-TOA law to find the speed of sound where the face of the transducer head was orientated. He found a six meter difference between the laser angle and what the computer was calculating. Simple trigonometry on a pad of paper was able to check what an advanced computer system was not.

NOAA Ship Pisces is also equipped with an advanced multibeam sonar. (Sonar stands for SOund NAvigation and Ranging.) In fact, there are only eight like it in the world. One of Todd’s goals before he retires from NOAA is to tweak it and write about it so other people know more about operating it. Since they are so few and you need to go to them, there are fewer publications about it.

Another mapping device is the side scan sonar. It is towed behind the vessel and creates a 300 meter picture with a 50 meter blind spot in the center, which is what is underneath the device. Hydrographic vessels have more sonars to compensate for this blind spot. The purpose of the mapping is to identify new habitat areas, therefore expanding the sampling universe of the SEAMAP Reef Fish Surveys.

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Up on the bridge looks much different. The lights are off and monitors are covered with red film to not ruin the crew’s night vision. Everything is black or red, with a little green coming from the radar displays. This is to see boats trying to cross too close in front of NOAA Ship Pisces or boats with their lights off. Lieutenant Noblitt and Ensign Brendel are manning the ship.

Ensign Brendel noted to me that, “We have all of this fancy equipment, but the most important equipment are these here binoculars.” They are always keeping a lookout. The technology on board is built for redundancy. There are two of most everything and the ship’s location is also marked on paper charts in case the modern equipment has problems.

There are international rules on the water, just like the rules of the road. The difference is there are no signs out here and it is even less likely you know who is following them. Each boat or ship has a series of lights that color codes who they are or what they are doing. Since NOAA Ship Pisces is restricted in maneuverability at night due to mapping, they have the right of way in most cases. It is also true that it takes longer for larger vessels to get out of the way of a smaller vessel, especially in those instances that the smaller one tries to pass a little too close. This did happen the night before. It reminds me of lifeguarding. It is mostly watching, punctuated with moments of serious activity where training on how to remain calm, collected, and smart is key.

Personal Log

It has been a privilege seeing and touching many species I have not witnessed before. Adding to the list of caught species is bonito (Sarda sarda) and red porgy (Pagrus pagrus). I always think it is funny when the genus and species is the same name. We have also seen Atlantic spotted dolphins (Stenella frontalis) jumping around. There are 21 species of marine mammals indigenous to the Gulf of Mexico, most in deep water off of the continental shelf. I also learned that there are no seals down here.

One of the neatest experiences this trip was interacting with a sharksucker (Echeneis naucrates). It has a pad that looks like a shoe’s sole that grips to create a suction that sticks them to their species of choice. The one we caught prefers hosts like sharks, turtles…and sometimes science teachers.

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Did You Know?

Fishing boats use colored lights to indicate what kind of fishing they are doing, as the old proverb goes red over white fishing at night, green over white trawling tonight. Vessels also use international maritime signal flags for communication during the day.

Mark Wolfgang: If a Fish Laughs in the Ocean and No One is There to Hear it, Does it Really Make a Sound? April 21, 2017

NOAA Teacher at Sea

Mark Wolfgang

Aboard NOAA Ship Reuben Lasker

April 11 – April 22, 2017

 

Mission: Spring Coastal Pelagic Species (Anchovy/Sardine) Survey

Geographic Area of Cruise: Pacific Ocean

Date: April 21, 2017

Weather Data from the Bridge:

Lat: 38o 2.4’N        Long: 123o 6.2’W
Air Temperature: 13.9oC (57oF)
Water Temperature: 12.9oC (55oF)
Wind speed: 12 knots (13.8 mph)
Barometer:   1014.97 mbar
Conditions:  Clear skies and the seas are pretty smooth

Scientific and Technology Log:

DSC00196
The Acoustics room on the Reuben Lasker

Today, I decided to learn more about the other key research part of the Coastal Pelagic Survey.  As the trawling is happening at night and the egg and larval collections during the day, acousticians are listening to what is below us.  Using this information, research scientists can assess the population of coastal pelagic species (CPS).  The acoustics room is full of stacks of computers, servers, monitors and organized wires.  NOAA researchers collect enormous amounts of data as we move down the 80 mile transects across the Pacific Ocean.  On this leg, we have not found many large schools of sardines or anchovies, but the data from acoustic-sampling did lead us to some jack mackerel.  I am going to try to explain some of the technology they use on the Reuben Lasker.reuben-lasker-acoustic-sampling

Simrad EK60 and EK80:  These are two sonar systems that use multiple frequencies to listen to the ocean right below the ship.  In the diagram, it is seen in green.  The EK80 is newer and is being tested on the Reuben Lasker.  It collects enormous amounts of data and acousticians are looking at how best to use that data.

Simrad ME70: This multibeam sonar (seen in orange in the diagram) listens to the water below and around the ship.  It would almost look like a fan.  This does not only tell us what is below, but what is beside the ship as well.

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The Simrad ME70

Simrad SX90: This is a long-range sonar (shown in gray) that looks at the surface for a good distance around the ship.  When I was there, they were analyzing 450 meter radius around the ship.  This is where the UAS would come in to use.  If a school of sardines or anchovies are seen on this sonar, they could possibly deploy the drone to fly over the school and take photographs.  Researchers could then analyze those photographs and collect appropriate data.  Researchers can also potentially use this system to see how the ship moving through the water effects the behavior of the school.

DSC00190
The Simrad SX90

Simrad MS70:   The MS70 is a multibeam sonar that also analyzes the water off the side of the ship.  It almost fills in the imaging gap left by the ME70.

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The Simrad MS70

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K-SYNC

All of these sonars are linked together by a program called K-SYNC.  This program makes sure that the sonars don’t “ping” at the same time and cause interference with all of the systems.  The Reuben Lasker also a very quiet propulsion system to limit the interference of the sound of the ship moving through the water.  The ship also has 3 hydrophones that can be used to listen to marine mammals.

Together these five sonar systems give the Reuben Lasker an incredible view of what is in the water under and around the ship.  This informs the trawls at night and together gives a good picture of the CPS in the waters of coastal California.

Personal Log:

So what do we do during the time we are not working?  The ship is full of movies, an exercise room, and snacks are available all day.  I have been able to read a couple books, watch a few movies with the science team, work on my blog and talk to crewmembers, and even watch some TV (including seeing the Penguins play a couple hockey games).  When you are on shift, there will be some downtime and then a bunch of activity as the net is pulled in.  I have also tried to soak in the clean ocean air and take moments just to enjoy the experience.  My Teacher At Sea voyage has been enjoyable, but I am looking forward to arriving back in San Francisco on April 22nd and flying home that night to be with my family.

Did you know?

Sonar, an acronym for SOund Navigation And Ranging, is a technique that uses sound to navigate, communicate, or detect objects on or under the surface of the water.  American naval architect, Lewis Nixon, invented the first sonar-like device in 1906.  Because of the demands of WWI, Paul Langevin constructed the first sonar set to detect submarines in 1915.

 

Denise Harrington: Tenacity – May 7, 2016

NOAA Teacher at Sea
Denise Harrington
Aboard NOAA Ship Pisces (In Port)
May 04, 2016 – May 17, 2016

Mission: SEAMAP Reef Fish Survey

Geographical Area of Cruise: Gulf of Mexico

Date: Saturday, May 7, 2016

Tenacity helps NOAA manage our seafood supply.

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Tenacity, otherwise known as perseverance or stamina, is a required skill at the National Oceanic and Atmospheric Administration (NOAA). Aboard NOAA Ship Pisces, we are all anxious to head out to collect data about the type and abundance of reef fish along the continental shelf and shelf edge of the Gulf of Mexico.  However, things don’t always go as planned. Much like the animals we study, scientists must rapidly adapt to their changing circumstances. Instead of waiting for a problem to be solved, fisheries biologists of all ages and experience work in the lab, using the newest, most sophisticated technology in the world to meet our demand for seafood.

As I ate dinner tonight in the mess (the area where the crew eats), I stared at the Pisces’ motto on the tablecloth, “patience and tenacity.”

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The Pisces is a “quiet” ship; it uses generators to supply power to an electric motor that turns the ship’s propeller. The ship’s motor (or a mysteriously related part) is not working properly, and without a motor, we will not sail. This change of plans provides other opportunities for me, and you, to learn about many fascinating projects developing in the lab. Sound science begins right here at the Southeast Fisheries Science Center Laboratory in Pascagoula, Mississippi.

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Kevin Rademacher, a fishery biologist in the Reef Fish Unit, meets me at the lab where he works when he isn’t at sea. As he introduces me to other biologists working in the protected species, plankton, and long line units, I begin to appreciate the great biodiversity of species in the Gulf of Mexico. I get a glimpse of the methods biologists use to conduct research in the field, and in the lab.

While it looks like a regular old office building on the outside, the center of the building is filled with labs where fish are taken to be discovered.  Mark Grace, a fisheries biologist in the lab, made one such discovery of a rare species of pocket shark on a survey in the gulf. The only other specimen of a pocket shark was found coast of Peru in 1979. Mark’s discovery raises more questions in my mind than answers.

When I met Mark, he explained that capability of technology to gather data has outpaced our ability to process it. “Twenty years ago, we used a pencil and a clipboard. Think about the 1980s when they started computerizing data points compared to the present time… maybe in the future when scientists look back on the use of computers in science, it will be considered to be as important as Galileo looking at the stars” he said. It’s important because as Mark also explains,  “This correspondence is a good example.  We can send text, website links, images, etc…and now its a matter of digital records that will carry in to the future.”

How do fishery biologists find fish?

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Charlie McVea, a retired NOAA marine biologist, and his trusty assistant Scout, pictured above, learned they may need more sophisticated equipment to locate fish.

Earth has one big connected ocean that covers the many features beneath it. Looking below the surface to the ocean floor, we find a fascinating combination of continental shelves, canyons, reefs, and even tiny bumps that make unique homes for all of the living creatures that live there.  Brandi Noble, one of 30-40 fishery biologists in the lab, uses very complicated sonar (sound) equipment to find “fish hot spots,” the kinds of places fish like to go for food, shelter and safety from predators. Fisheries sonar sends pulses of sound, or pings, into the water.  Fishery biologists are looking for a varied echo sound that indicates they’ve found rocky bottoms, ledges, and reefs that snapper and grouper inhabit.

The sonar can also survey fish in a non-invasive way. Most fish have a swim bladder, or a gas filled chamber, which reflects sonar’s sound waves.  A bigger fish will create a returning echo of greater strength. This way, fisheries biologists can identify and count fish without hurting them.

sonar fish
The circular image shows a three-dimensional map NOAA scientists created from the sonar data they collected about the seafloor and a school of fish.

Ship Pisces uses a scientific methods to survey, determining relative abundance and types of fish in each area. They establish blocks of habitat along the continental shelf to survey and then randomly sample sites that they will survey with video cameras, CTD (measures temperature, salinity, and dissolved oxygen in the water), and fishing. Back in the lab, they spend hours, weeks, and years, analyzing the data they collect at sea. During the 2012 SEAMAP Reef Fish Survey, the most common reef fish caught were 179 red snapper (Lutjanus campechanus), 22 vermillion snapper (Rhomboplites aurorubens), and 10 red porgy (Pagrus pagrus).  Comparing the 2012 data with survey results from 2016 and other years will help policy makers develop fishing regulations to protect the stock of these and other tasty fish.

How do fishery biologists manage all the information they collect during a survey?

Scientists migrate between offices and labs, supporting each other as they identify fish and marine mammals from previous research expeditions.

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Kevin Rademacher, at work in the lab.

Our mission, the SEAMAP Reef Fish Survey has been broken into four parts or legs.  The goal is to survey some of the most popular commercially harvested fish in the Gulf of Mexico.  Kevin Rademacher is the Field Party Chief for Leg 1 and Leg 3 of the survey.

Last week, he showed me collections of frozen fish, beetle infested fish, and fish on video. At one point the telephone rang, it was Andrew Paul Felts, another biologist down the hall. “Is it staying in one spot?” Kevin asks. “I bet it’s Chromis. They hang over a spot all the time.”

We head a couple doors down and enter a dark room.  Behind the blue glow of the screen sits Paul, working in the dark, like the deep water inhabitants of the video he watches. Paul observes the physical characteristics of a fish: size, shape, fins, color.  He also watches its behavior. Does it swim in a school or alone?  Does it stay in one spot or move around a lot?  He looks at its habitat, such as a rocky or sandy bottom, and its range, or place on the map.

As you watch the video below, observe how each fish looks, its habitat, and its behavior.

To learn about fisheries, biologists use the same strategies students at South Prairie Elementary use.   Paul is using his “eagle eyes,” or practiced skills of observation, as he identifies and counts fish on the screen.   All the scientists read, re-read and then “read the book a third time” like a “trying lion” to make sense out of their observations.  Finally, Paul calls Kevin, the “wise owl,” to make sure he isn’t making a mistake when he identifies a questionable fish. paul screen

Using Latin terminology such as “Chromis” or “Homo” allows scientists to use the same names for organisms. This makes it easier for scientists worldwide, who speak different languages, to communicate clearly with each other as they classify the living things they study.

I appreciate how each member of the NOAA staff, on land and at sea, look at each situation as a springboard to more challenging inquiry.  They share with each other and with us what they have learned about the diversity of life in the ocean, and how humans are linked to the ocean.  With the knowledge we gain from their hard work and tenacity, we can make better choices to protect our food supply and support the diversity of life on Earth.

 

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Spined Pygmy Shark Jaw (Squaliolus laticaudus)

Personal Log

Crew members tell me that every day at sea is a Monday.  In port, they are able to spend time with family and their communities.  I have been able to learn a bit about Pascagoula, kayak with locals, and see many new birds like the least tern, swallow tailed kite, eastern bluebird and clapper rail.  Can you guess what I ate for dinner last night?P1050747

 

 

 

 

Nichia Huxtable: Time to Make a Map, May 8, 2016

Sunset XBT deployment off Shimada

NOAA Teacher at Sea

Nichia Huxtable

Aboard NOAA Ship Bell M. Shimada

April 28 – May 9, 2016

Mission: Mapping CINMS
Geographical area of cruise: Channel Islands, California
Date: May 8, 2016
Weather Data from the Bridge:

Science and Technology Log

Seafloor in CINMS
Seafloor in the CINMS

In previous posts, I’ve discussed the ME70 multibeam sonar on board Shimada. You’d think that I’ve told you all there is to know about the wondrous data this piece of equipment provides, but oh, no, dear readers, I’ve merely scraped the surface of that proverbial iceberg. In this post, I will explain how the raw data from the ME70 is used to create important seafloor maps. Heck, I’ll even throw in a shipwreck! Everyone loves shipwrecks.

Nichia Huxtable, Diana Watters, ME70, and EK60; aboard Shimada
Nichia Huxtable, Diana Watters, ME70, and EK60; aboard Shimada

Back to the multibeam. As you may remember, the ME70 uses many beams of sonar to capture a 60 degree image of the water column. It collects A LOT of data, one survey line at a time. Lots of data are good, right? Well, if you want to map the bottom of the ocean, you don’t need ALL the data collected by the ME70, you just need some of it. Take, for example, fish. You don’t want big balls of fish obscuring your view of the seafloor, you just want the seafloor! Leave the schools of fish for Fabio.

Kayla Johnson aboard NOAA Ship Bell M. Shimada
Mapping maven Kayla Johnson

The person you need to make your seafloor map is Kayla Johnson. First, she sends the raw data to a program called MatLab. This nifty software separates the bottom data from all the other stuff in the water column and packages it in something called a .gsf file. Next, this .gsf file goes to this huge processing program called CARIS HIPS, where it is converted into an something called HDCS data.

You’d think that all you’d need to make an accurate seafloor map would be data from the multibeam, but it is actually much more complicated than that (of course you knew that! just look at how long this blog post is). Think about it: while you’re running your survey lines and collecting data, the ocean and, therefore, the ship are MOVING. The ship is heaving, rolling, and pitching, it’s travelling in different directions depending on the survey line, the tides are coming in and out, the temperature and salinity of the water varies, etc. etc. All of these variables affect the data collected by the ME70 and, hence, must be accounted for in the CARIS software. Remember how I said it was HUGE? This is why.

Cross-section of the topography found in the CINMS
Cross-section of the topography found in the CINMS

Everyone still with me? Ok, let’s continue processing this data so that Kayla can make our beautiful map. Next up, she’s going to have to load data into CARIS from the POS. POSMV (POSition of Marine Vehicles) is a software interface used on the ship that collects real-time data on where we are in relation to the water (heave, pitch, and roll).  She’s also going to load into CARIS the local tide information, since the ship will be closer to the seafloor at low tide than at high. Not including tidal change is a good way to get a messed-up map! Once the POSMV and tide files are loaded into CARIS, they are applied to the survey line.

Completed map around San Miguel Island
Completed map around San Miguel Island

Next, Kayla has to compute the TPU (Total Propagated Uncertainty). I could spend the next four paragraphs explaining what it is and how it’s computed, but I really don’t feel like writing it and you probably wouldn’t want to read it. Let’s just say that nothing in life is 100% certain, so the TPU accounts for those little uncertainties.

Since the data was collected using multiple beams at a wide angle, there will be beams returning bad data, especially at the edges of the collection zone. Sometime a bad data point could be a fish, but most often bad data happens when there is an abrupt change in seafloor elevation and the beams can’t find the bottom. So, Kayla will need to manually clean out these bad data points in order to get a clean picture of the seafloor.

Almost done! Last, Kayla makes the surface. All the data points are gridded to a certain resolution based on depth (lots of explanation skipped here…you’re welcome), with the end result being a pretty, pretty picture of the bottom of the seafloor. Phew, we made it! These seafloor maps are incredibly important and have numerous applications, including fisheries management, nautical charting, and searching for missing airplanes and shipwrecks (see! I told you there would be a shipwreck!). I’ll be getting into the importance of this mapping cruise to the Channel Islands Marine Sanctuary in my final post, so stay tuned.

Endnote: A word about XBTs                                                                                                      

Deploying an XBT off Shimada
Deploying an XBT off Shimada

 Before all your data are processed, you need to know how fast the sound waves are travelling through the water. When sound is moving through water, changes in temperature and salinity can bend the wave, altering your data. An XBT is an expendable bathythermograph that is sent overboard every four hours. It transmits temperature and salinity readings throughout its quick trip to the ocean bottom, allowing the computer to make data adjustments, as needed.

 

 

Did You Know?
Hey, you’ve made it to the bottom of this post! If you are interested in seafloor mapping, have I got an institute of higher learning for you. The College of Charleston has a program called BEAMS, which trains future ocean surveyors and includes a course called Bathymetric Mappings. Three of the hip young scientists on board have taken this course and it seems to be pretty amazing. If you love sailing the high seas AND data processing, you might want to check it out.

Emily Whalen: Station 381–Cashes Ledge, May 1, 2015

NOAA Teacher at Sea
Emily Whalen
Aboard NOAA Ship Henry B. Bigelow
April 27 – May 10, 2015

Mission: Spring Bottom Trawl Survey, Leg IV
Geographical Area of Cruise: Gulf of Maine

Date: May 1, 2015

Weather Data from the Bridge:
Winds:  Light and variable
Seas: 1-2ft
Air Temperature:   6.2○ C
Water Temperature:  5.8○ C

Science and Technology Log:

Earlier today I had planned to write about all of the safety features on board the Bigelow and explain how safe they make me feel while I am on board.  However, that was before our first sampling station turned out to be a monster haul!  For most stations I have done so far, it takes about an hour from the time that the net comes back on board to the time that we are cleaning up the wetlab.  At station 381, it took us one minute shy of three hours! So explaining the EEBD and the EPIRB will have to wait so that I can describe the awesome sampling we did at station 381, Cashes Ledge.

This is a screen that shows the boats track around the Gulf of Maine.  The colored lines represent the sea floor as determined by the Olex multibeam.  This information will be stored year after year until we have a complete picture of the sea floor in this area!
This is a screen that shows the boats track around the Gulf of Maine. The colored lines represent the sea floor as determined by the Olex multibeam. This information will be stored year after year until we have a complete picture of the sea floor in this area!

Before I get to describing the actual catch, I want to give you an idea of all of the work that has to be done in the acoustics lab and on the bridge long before the net even gets into the water.

The bridge is the highest enclosed deck on the boat, and it is where the officers work to navigate the ship.  To this end, it is full of nautical charts, screens that give information about the ship’s location and speed, the engine, generators, other ships, radios for communication, weather data and other technical equipment.  After arriving at the latitude and longitude of each sampling station, the officer’s attention turns to the screen that displays information from the Olex Realtime Bathymetry Program, which collects data using a ME70 multibeam sonar device attached to bottom of the hull of the ship .

Traditionally, one of the biggest challenges in trawling has been getting the net caught on the bottom of the ocean.  This is often called getting ‘hung’ and it can happen when the net snags on a big rock, sunken debris, or anything else resting on the sea floor.  The consequences can range from losing a few minutes time working the net free, to tearing or even losing the net. The Olex data is extremely useful because it can essentially paint a picture of the sea floor to ensure that the net doesn’t encounter any obstacles.  Upon arrival at a site, the boat will cruise looking for a clear path that is about a mile long and 300 yards wide.  Only after finding a suitable spot will the net go into the water.

Check out this view of the seafloor.  On the upper half of the screen, there is a dark blue channel that goes between two brightly colored ridges.  That's where we dragged the net and caught all of the fish!
Check out this view of the seafloor. On the upper half of the screen, there is a dark blue channel that goes between two brightly colored ridges. We trawled right between the ridges and caught a lot of really big fish!

The ME70 Multibeam uses sound waves to determine the depth of the ocean at specific points.  It is similar to a simpler, single stream sonar in that it shoots a wave of sound down to the seafloor, waits for it to bounce back up to the ship and then calculates the distance the wave traveled based on the time and the speed of sound through the water, which depends on temperature.  The advantage to using the multibeam is that it shoots out 200 beams of sound at once instead of just one.  This means that with each ‘ping’, or burst of sound energy, we know the depth at many points under the ship instead of just one.  Considering that the multibeam pings at a rate of 2 Hertz to 0.5 Herts, which is once every 0.5 seconds to 2 seconds, that’s a lot of information about the sea floor contour!

This is what the nautical chart for Cashes Ledge looks like. The numbers represent depth in fathoms.  The light blue lines are contour lines.  The places where they are close together represent steep cliffs.  The red line represents the Bigelow’s track. You can see where we trawled as a short jag between the L and the E in the word Ledge

The stations that we sample are randomly selected by a computer program that was written by one of the scientists in the Northeast Fisheries Science Center, who happens to be on board this trip.  Just by chance, station number 381 was on Cashes Ledge, which is an underwater geographical feature that includes jagged cliffs and underwater mountains.  The area has been fished very little because all of the bottom features present many hazards for trawl nets.  In fact, it is currently a protected area, which means the commercial fishing isn’t allowed there.  As a research vessel, we have permission to sample there because we are working to collect data that will provide useful information for stock assessments.

My watch came on duty at noon, at which time the Bigelow was scouting out the bottom and looking for a spot to sample within 1 nautical mile of the latitude and longitude of station 381.  Shortly before 1pm, the CTD dropped and then the net went in the water.  By 1:30, the net was coming back on board the ship, and there was a buzz going around about how big the catch was predicted to be.  As it turns out, the catch was huge!  Once on board, the net empties into the checker, which is usually plenty big enough to hold everything.  This time though, it was overflowing with big, beautiful cod, pollock and haddock.  You can see that one of the deck crew is using a shovel to fill the orange baskets with fish so that they can be taken into the lab and sorted!

You can see the crew working to handling all of the fish we caught at Cashes Ledge.  How many different kinds of fish can you see?
You can see the crew working to handling all of the fish we caught at Cashes Ledge. How many different kinds of fish can you see? Photo by fellow volunteer Joe Warren

 

At this point, I was standing at the conveyor belt, grabbing slippery fish as quickly as I could and sorting them into baskets.  Big haddock, little haddock, big cod, little cod, pollock, pollock, pollock.  As fast as I could sort, the fish kept coming!  Every basket in the lab was full and everyone was working at top speed to process fish so that we could empty the baskets and fill them up with more fish!  One of the things that was interesting to notice was the variation within each species.  When you see pictures of fish, or just a few fish at a time, they don’t look that different.  But looking at so many all at once, I really saw how some have brighter colors, or fatter bodies or bigger spots.  But only for a moment, because the fish just kept coming and coming and coming!

Finally, the fish were sorted and I headed to my station, where TK, the cutter that I have been working with, had already started processing some of the huge pollock that we had caught.  I helped him maneuver them up onto the lengthing board so that he could measure them and take samples, and we fell into a fish-measuring groove that lasted for two hours.  Grab a fish, take the length, print a label and put it on an envelope, slip the otolith into the envelope, examine the stomach contents, repeat.

Cod, pollock and haddock in baskets
Cod, pollock and haddock in baskets waiting to get counted and measured. Photo by Watch Chief Adam Poquette.

Some of you have asked about the fish that we have seen and so here is a list of the species that we saw at just this one site:

  • Pollock
  • Haddock
  • Atlantic wolffish
  • Cod
  • Goosefish
  • Herring
  • Mackerel
  • Alewife
  • Acadian redfish
  • Alligator fish
  • White hake
  • Red hake
  • American plaice
  • Little skate
  • American lobster
  • Sea raven
  • Thorny skate
  • Red deepsea crab

 

 

 

 

I think it’s human nature to try to draw conclusions about what we see and do.  If all we knew about the state of our fish populations was based on the data from this one catch, then we might conclude that there are tons of healthy fish stocks in the sea.  However, I know that this is just one small data point in a literal sea of data points and it cannot be considered independently of the others.  Just because this is data that I was able to see, touch and smell doesn’t give it any more validity than other data that I can only see as a point on a map or numbers on a screen.  Eventually, every measurement and sample will be compiled into reports, and it’s that big picture over a long period of time that will really allow give us a better understanding of the state of affairs in the ocean.

Sunset from the deck of the Henry B. Bigelow
Sunset from the deck of the Henry B. Bigelow

Personal Log

Lunges are a bit more challenging on the rocking deck of a ship!
Lunges are a bit more challenging on the rocking deck of a ship!

It seems like time is passing faster and faster on board the Bigelow.  I have been getting up each morning and doing a Hero’s Journey workout up on the flying bridge.  One of my shipmates let me borrow a book that is about all of the people who have died trying to climb Mount Washington.  Today I did laundry, and to quote Olaf, putting on my warm and clean sweatshirt fresh out of the dryer was like a warm hug!  I am getting to know the crew and learning how they all ended up here, working on a NOAA ship.  It’s tough to believe but a week from today, I will be wrapping up and getting ready to go back to school!

Theresa Paulsen: Mission Accomplished, April 2, 2015

NOAA Teacher at Sea
Theresa Paulsen
Aboard NOAA Ship Okeanos Explorer
March 16-April 3rd

Mission: Caribbean Exploration (mapping)
Geographical Area of Cruise: Puerto Rico Trench
Date: April 2, 2015

Weather Data from the Bridge: Partly Cloudy, 26 C, Wind speed 12 knots, Wave height 1-2ft, Swells 2-4ft.

Science and Technology Log:

What are the mappers up to?

After we completed our two priority areas of the cruise, the mappers have been using Knudson subbottom sonar to profile the bottom of the trench. Meme Lobecker, the expedition coordinator sends that data directly to the United States Geological Survey (USGS) for processing. They returned some interesting findings.

The subbottom sonar sends a loud “chirp” to the bottom. It penetrates the ocean floor. Different sediment layers reflect the sound differently so the variation and thickness of the layers can be observed. The chirp penetration depth varies with the sediments. Soft sediments can be penetrated more easily. In the picture below, provided by USGS, you can see hard intrusions with layers of sediments filling in spaces between.

image
The intrusions are basement relief, likely uplifting deformation ridges created by the subduction of the North American Plate. The subduction is now oblique, with the North American and Caribbean plates mostly sliding past each other now – sort of like the San Andreas Fault – but there is still some subduction happening. Subbottom Image and caption courtesy of USGS.

How does the bathymetry look?

In the last two days, I have been really enjoying the incredible details in the bathymetry data the multibeam sonar has gathered. We mapped over 15,000 square miles on our voyage! Using computer software we can now look at the ocean floor beneath us. I tried my hand at using Fledermaus software to make fly-over movies of the area we surveyed (or should I say swim-over movies). Check them out:

I also examined some of the backscatter data. In backscatter images soft surfaces are darker, meaning the signal return is weaker, and the hard surfaces are whiter due to stronger returns. One of the interns, Chelsea Wegner, studied the bathymetry and backscatter data for possible habitats for corals. She looked for steep slopes in the bathymetry and hard surfaces with the backscatter, since corals prefer those conditions.

Intern poster project
Intern Poster Project by Chelsea Wegner

Chelsea Wegner Poster (pdf)

On the next leg, the robotic vehicle on the ship will be used to examine some of the areas we were with high-definition cameras. You can watch the live stream here. You can also see some of the images and footage from past explorations here.
This is a short video from the 2012 expedition to the Gulf of Mexico to tempt you into tuning in for more.

Personal Log:

The people on this vessel have been blessed with adventurous spirits and exciting careers. Throughout the cruise, I heard about and then came to fully understand the difficulty of being away from family when they need us.

I would like to dedicate this last blog to my father, Tom Wichman. He passed away this morning at 80 years of age after battling more than his share of medical issues.  As I rode the ship in today I felt him beside me. Together we watched the pelicans and the boobies fly by. I am very glad I was able to take him on a “virtual” adventure to the Caribbean. He loved the pictures and the blog. I thank the NOAA Teacher at Sea program for helping me make him proud one last time.

My parents
My Parents, Tom and Kate Wichman

“To know how to wonder is the first step of the mind toward discovery” – L. Pasteur. These words decorate my classroom wall but are epitomized by the work that the NOAA Okeanos Explorer and the Office of Exploration and Research (OER) do each day.

Thank you to the Meme, the CO, XO, the science team, and the entire crew aboard the Okeanos for teaching me as much as you did and for helping me get home when I needed to be with family. I wish you all the best as you continue to explore our vast oceans! My students and I will be watching and learning from you!

I would also like to thank all of the people who followed this blog. Your support and interest proves that you too are curious by nature. Life is much more interesting if you hold on to that sense of wonder, isn’t it?

Answers to My Previous Questions of the Day Polls:

1.  Bathymetry is the study of ocean depths and submarine topography.

2. The deepest zone in the ocean is called the hadal zone, after Hades the Greek God of the underworld.

3.  It takes the vessel 19 hours and 10 minutes to make enough water for 46 people each using 50 gallons per day if each of the two distillers makes 1 gallon per minute.

4.  NOAA line offices include:

  • National Environmental Satellite, Data, and Information Service
  • National Marine Fisheries Service
  • National Ocean Service
  • National Weather Service
  • Office of Marine & Aviation Operations
  • Office of Oceanic and Atmospheric Research

5. The pressure on the a diver at 332.35m is 485 pounds per square inch!

6.  The deepest part of the Puerto Rico Trench is known as the Milwaukee Deep.

Thank you for participating!  I hope you learned something new!

Sarah Raskin: Teacher at Sea Day 4, March 16, 2015

NOAA Teacher at Sea

Sarah Raskin

Aboard NOAA Ship Bell M. Shimada

March 13-18, 2015


Mission: Channel Islands Deep-Sea Coral Study

Geographic Area: Channel Islands, California

Date: March 16, 2015

Day 4: Monday 3/16/15

The visiting sonar technician left this afternoon on NOAA’s Shark Cat boat after working diligently to fix the ship’s sonar system throughout the past few days.  As of now, the ME 70 sonar is up and running.  This equals exciting news for the sonar team that has been waiting patiently to begin their projects.  The Shimada actually has two sonar machines; one works with a single beam, while the other, the ME 70 has multiple beams that can cover a much greater amount of territory in the same amount of time.

Shark Cat boat
The Shark Cat alongside the Shimada

How does sonar work?

Sonar technology is a way for us to create images of what is below the surface of the ocean.  The sonar system, which is attached to the bottom of the ship, sends out an acoustic signal towards the ocean floor and then measures how long it takes for the sound to bounce back to the boat. By measuring this, the sonar creates a picture of the depth of the ocean floor in that area.  

Mike and Will
Mike and Will look at data generated from the sonar system

A secondary measurement that is also occurring when the sonar machine is running is called backscatter.  Backscatter measures the intensity, or loudness, of the sound as it echoes back to the ship.  The softer the sound when it reflected back means the softer the type of surface it is bouncing off of, such as sand.  The louder and more severe the sound is equates to a harder surface floor, such as rocky ledges.  As Andy explained to me, think about bouncing a ping-pong ball on a carpet vs. hardwood floor.  The ping-pong ball will have a much stronger bounce off of a hard surface v. a softer one.  Will also explained that based on the backscatter sound we can determine fine details such as whether the sand is fine or coarse.

Simrad ME70
Simrad ME70, Scientific multibeam echo sounder

Both of these sonar features create an image of what the ocean floor looks like, its physical features, habitat types and any potential hazards that may exist below the surface.  This is critical for creating nautical charts and it is also important for the navigation of the ROV, so it doesn’t stumble upon any unexpected obstacles while traveling underwater. 

Shimada seamount
An example of an image created by the sonar system

Another feature that sonar is used for on this ship is to measure fish abundance.  The sound waves travel down and bounce off of the fishes’ swim bladders.  Swim bladders are gas filled bladders found in many fish that helps them stay buoyant.  Using this method, scientists could use sonar to gauge fish populations, instead of catching fish to see what is out there.

An example of an image created by the sonar system
Scientists looking at sonar screens

So far in the trip, Laura Kracker and her team (Mike Annis, Will Sautter and Erin Weller) have been using the working sonar to map fish populations in the area.  Tonight, however, they will use the ME 70 for a test run to map out areas of the Channel Islands National Marine Sanctuary that have never been mapped before!  This data could be used to create brand new nautical maps, to help scientists have a better idea of what the hidden part of our sanctuary looks like and to determine which regions might be best habitats for fish or coral.   Tomorrow, the ROV team will send the ROV to the sites that were mapped the previous night to check out features that were discovered on the seafloor and to explore the newly mapped regions. 

sonar team
The sonar team hard at work (from left Mike, Will, Laura, Erin)

Life at Sea

When setting out on this journey, students asked me what life would be like living on a ship.  I spoke with several of the crew members on the ship about what it is like to be out at sea for days at a time.   So here is an image of what it has been like so far, from the perspective of some of the crew and from my own experiences:

NOAA Ship Bell M. Shimada
The Bell M. Shimada by the Channel Islands

The Bell M. Shimada is an enormous ship, over 200 feet in length.  I have been here for four days now and still have not explored the entire place!  The ship is approx. six stories tall, though on the ship they refer to the different levels as decks, not stories.  The Shimada is run from a platform on the third deck, known as the bridge.  The steering of the ship takes place from the bridge and there is always an assigned lookout person, whose job is to look out the windows to see what is going on around the ship.  The bridge is also equipped with radars that can detect boat traffic or other obstacles.  

A lot of communication goes back and forth between the scientists in the ROV command room and the bridge.  The bridge must ensure that the ship stays steady and follows the ROV during its dive.  If the ship moves too much it can yank the ROV around or the cables from the ROV could get caught or damaged under the ship.  

The Bridge
The Bridge
Andy and CO
Andy shows our Commanding Officer how to operate the ROV

The areas where we sleep on the ship are called staterooms.  Almost all of them consist of bunk beds and have a toilet and shower area.  I am rooming with Erin, one of the scientists working on the sonar mapping project.  Erin and her team work during the night after the ROV runs, so typically she is going to bed shortly before I wake up for the day.  We have both been working hard to stay quiet enough to let each other catch up on our sleep!

stateroom
One of the staterooms

The Shimada has many features that I was not expecting on a ship, such as an exercise room equipped with treadmills and weights.  We even have Internet access here!  Another unexpected feature is the lounge/ theater room that is across the hall from my stateroom.  It has plush reclining chairs, a huge flat screen TV, and all the DVDs you could ever hope to watch, including the newest movies. 

When talking with the crew about what they love most about their jobs, many of them referred to how being part of a NOAA boat allows them incredible travel opportunities.  One person I spoke with has been to 52 different countries throughout his career with NOAA!  Another benefit of a maritime career such as this is that NOAA pays for part of your education.  It requires special schooling and credentials to be able to be an engineer or commanding officer on a ship, and NOAA helps offset those costs.  One of the biggest challenges of the job, however, is being away from family and friends for such long periods of time.  Some of the crew explained to me that they may be out at sea for 30 days at a time, sometimes even longer.

            One great perk to life aboard is the food.  Two chefs prepare all of the meals on the Shimada for us.  Similar to our lunch time at school, the meals are served at the same time each day in what is called the mess hall.  If you oversleep and miss breakfast, not too worry; there is cereal and other snacks available around the clock.  They serve breakfast, lunch and dinner on the ship, and we have even had the treat of fresh salads and homemade desserts! 

stewards
2C Boyd and CS Phillips preparing delicious meals

The ship stays running smoothly thanks to the help of the engineers and crew members.  They work behind the scenes around the clock to keep the ship afloat.

Chief Engineer
Our Chief Engineer
ET and SF
Our Electronics Tech and SF Alves

My absolute favorite location on the ship is called the flying bridge.  It has 3 tall chairs that look out over the ocean and an almost 360 degree view of the sea.  The chairs have been used on previous excursions for scientists to sit and count marine mammals as part of their survey.  It is a great place to watch the sunset from.

view from flying bridge
The view from the flying bridge
sunset
An epic sunset over the Islands

Lauren Wilmoth: “Wreckish looking rock?” October 15, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Wednesday, October 15th, 2014

Weather Data from the Bridge
Air Temperature: 4.4 °C
Wind Speed: 5 knots
Latitude: 57°56.9′ N
Longitude: 153°05.8′ W

Science and Technology Log

Thank you all for the comments you all have made.  It helps me decide what direction to go in for my next post.  One question asked, “How long does it take to map a certain area of sea floor?”  That answer, as I responded, is that it depends on a number of factors including, but not limited to, how deep the water is and how flat the floor is in that area.

To make things easier, the crew uses an Excel spreadsheet with mathematical equations already built-in to determine the approximate amount of time it will take to complete an area.  That answer is a bit abstract though.  I wanted an answer that I could wrap my head around.  The area that we are currently surveying is approximately 25 sq nautical miles, and it will take an estimated 10 days to complete the surveying of this area not including a couple of days for setting up tidal stations.  To put this in perspective, Jefferson City, TN is approximately 4.077 sq nautical miles.  So the area we are currently surveying is more than 6 times bigger than Jefferson City!  We can do a little math to determine it would take about 2 days to survey an area the size of Jefferson City, TN assuming the features are similar to those of the area we are currently surveying.

Try to do the math yourself!  Were you able to figure out how I got 2 or 3 days?

Since we’re talking numbers, Rainier surveyed an area one half the size of Puerto Rico in 2012 and 2013!  We can also look at linear miles.  Linear miles is the distance they traveled while surveying.  It takes into account  all of the lines the ship has completed.  In 2012 and 2013, Rainier surveyed the same amount of linear nautical miles that it would take to go from Newport, Oregon to the South Pole Station and back!

Area we are currently surveying.
Area we are currently surveying (outlined in red) with some depth data we have collected.

Casting a CTD (Conductivity, Temperature, and Depth) gauge.
Casting a CTD (Conductivity, Temperature, and Depth) gauge.

Monday, I went on a launch to collect sonar data.  This is my first time to collect sonar data since I started this journey.  Before we could get started, we had to cast a CTD (Conductivity, Temperature and Depth) instrument.  Sound travels a different velocities in water depending on the salinity, temperature, and pressure (depth), so this instrument is slowly cast down from the boat and measures all of these aspects on its way to the ocean floor.  Sound travels faster when there is higher salinity, temperature, and pressure.  These factors can vary greatly from place to place and season to season.

Imagine how it might be different in the summertime versus the winter.  In the summertime, the snow will be melting from the mountains and glaciers causing a increase in the amount of freshwater.  Freshwater is less dense than saltwater, so it mainly stays on top.  Also, that glacial runoff is often much colder than the water lower in the water column.  Knowing all of this, where do you think sound will travel faster in the summertime?  In the top layer of water or a lower layer of water?  Now you understand why it is so important to cast a CTD to make sure that our sonar data is accurate.  To learn more about how sound travels in water, click here.

TeacheratSea 033 (5)
I’m driving the boat.

After casting our CTD, we spent the day running the sonar up and down and up and down the areas that needed to be surveyed.  Again, this is a little like mowing the lawn.  At one point, I was on bow watch.  On bow watch, you sit at the front of the boat and look out for hazards.  Since this area hasn’t been surveyed since before 1939, it is possible that there could be hazards that are not charted.  Also, I worked down in the cabin of the boat with the data acquisition/sonar tuning. Some important things to do below deck including communicating the plan of attack with the coxswain (boat driver), activating the sonar, and adjusting the sonar for the correct depth.  I helped adjust the range of the sonar which basically tells the sonar how long to listen.  If you are in deeper water, you want the sonar to listen longer, because it takes more time for the ping to come back.  I also adjusted the power which controls how loud the sound ping is.  Again, if you are surveying a deeper area, you might want your ping to be a little louder.

Eli working the sonar equipment.
Eli working the sonar equipment.

Tuesday, I helped Survey Tech Christie Rieser and Physical Scientist Fernando Ortiz with night processing.  When the launches come back after acquiring sonar data, someone has to make all that data make sense and apply it to the charts, so we can determine what needs to be completed the following day.  Making sense of the data is what night processing is all about.  First, we converted the raw data into a form that the program for charting (CARIS) can understand.  The computer does the converting, but we have to tell it to do so.  Then, we apply all of the correctors that I spoke about in a previous blog in the following order: POS/MV (Position and Orientation Systems for Marine Vessels) corrector, Tides corrector, and CTD (Conductivity, Temperature, and Depth) corrector.  POS/MV corrects for the rocking of the boat.  For the tides corrector, we use predicted tides for now, and once all the data is collected from our tidal stations, we will add that in as well.  Finally, the CTD corrects for the change in sound velocity due to differences in the water as I discussed above.

After applying all of the correctors, we have the computer use an algorithm (basically a complicated formula) to determine, based on the data, where the sea floor is.  Basically, when you are collecting sonar data there is always going to be some noise (random data that is meaningless) due to reflection, refraction, kelp, fish, and even the sound from the boat.  The algorithm is usually able to recognize this noise and doesn’t include it when calculating the location of the seafloor.  The last step is manually cleaning the data.  This is where you hide the noise, so you can get a better view of the ocean floor.  Also, when you are cleaning, you are double checking the algorithm in a way, because some things that are easy for a human to distinguish as noise may have thrown off the algorithm a bit, so you can manually correct for that. Cleaning the data took the longest amount of time.  It took a couple of hours.  While processing the data, we did notice a possible ship wreck, but the data we have isn’t detailed enough to say whether it’s a shipwreck or a rock.  Senior Tech Jackson noted in the acquisition log that it was “A wreckish looking rock or a rockish looking wreck.”  We are going to have the launches go over that area several more times today to get a more clear picture of is going on at that spot.

H12662_DN195_2804 This is an example of noisy data. In this case, the noise was so great that the algorithm thought the seafloor went down 100 extra meters. Manually cleaning the data can adjust for this so our end product is accurate. The actual seafloor in this case is the relatively straight line at about 100 meters depth.
This is an example of noisy data. In this case, the noise was so great that the algorithm thought the seafloor went down 100 extra meters. Manually cleaning the data can adjust for this so our end product is accurate. The actual seafloor in this case is the relatively straight line at about 100 meters depth.

Personal Log 

Monday was the most spectacular day for wildlife viewing!  First, I saw a bald eagle.  Then, I saw more sea otters.  The most amazing experience of my trip so far happened next.  Orcas were swimming all around us.  They breached (came up for air) less than 6 feet from the boat.  They were so beautiful!  I got some good pictures, too!  As if that wasn’t good enough, we also saw another type of whale from far away.  I could see the blow (spray) from the whale and a dorsal fin, but I am not sure if it is was a Humpback Whale or a Fin Whale.  Too cool!

Bald Eagle Sighting!
Bald Eagle Sighting!

Sea otter
Sea otter

TeacheratSea 067 (4)
Orca!

Very close orca!
Very close orca!

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Did You Know? 

Killer whales are technically dolphins, because they are more closely related to other dolphins than they are to whales.

Lauren Wilmoth: Shore Party, October 12, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Sunday, October 12, 2014

Weather Data from the Bridge
Air Temperature: 1.92 °C
Wind Speed: 13 knots
Latitude: 58°00.411′ N
Longitude: 153°10.035′ W

Science and Technology Log

The top part of a tidal station.  In the plastic box is a computer and the pressure gauge.
The top part of a tidal station. In the plastic box is a computer and the pressure gauge.

In a previous post, I discussed how the multibeam sonar data has to be corrected for tides, but where does the tide data come from?  Yesterday, I learned first hand where this data comes from.  Rainier‘s crew sets up temporary tidal stations that monitor the tides continuously for at least 30 days.  If we were working somewhere where there were permanent tidal station, we could just use the data from the permanent stations.  For example, the Atlantic coast has many more permanent tidal stations than the places in Alaska where Rainier works.  Since we are in a more remote area, these gauges must be installed before sonar data is collected in an area.

We are returning to an area where the majority of the hydrographic data was collected several weeks ago, so I didn’t get to see a full tidal station install, but I did go with the shore party to determine whether or not the tidal station was still in working condition.

A tidal station consists of several parts: 1) an underwater orifice 2) tube running nitrogen gas to the orifice 3) a nitrogen tank 4) a tidal gauge (pressure sensor and computer to record data) 5) solar panel 6) a satellite antennae.

Let me explain how these things work.  Nitrogen is bubbled into the orifice through the tubing.  The pressure gauge that is located on land in a weatherproof box with a laptop computer is recording how much pressure is required to push those bubbles out of the orifice.  Basically, if the water is deep (high tide) there will be greater water pressure, so it will require more pressure to push bubbles out of the orifice.  Using this pressure measurement, we can determine the level of the tide.  Additionally, the solar panel powers the whole setup, and the satellite antennae transmits the data to the ship.  For more information on the particulars of tidal stations click here

Tidal station set-up.  Drawing courtesy of Katrina Poremba.
Tidal station set-up. Drawing courtesy of Katrina Poremba.

Rainier is in good hands.
Rainier is in good hands.

The tidal station in Terror Bay did need some repairs.  The orifice was still in place which is very good news, because reinstalling the orifice would have required divers.  However, the tidal gauge needed to be replaced.  Some of the equipment was submerged at one point and a bear pooped on the solar panel.  No joke!

After the tidal gauge was installed, we had to confirm that the orifice hadn’t shifted.  To do this, we take manual readings of the tide using a staff that the crew set-up during installation of the tidal station.  To take manual (staff) observations, you just measure and record the water level every 6 minutes.   If the manual (staff) observations match the readings we are getting from the tidal gauge, then the orifice is likely in the correct spot.

Just to be sure that the staff didn’t shift, we also use a level to compare the location of the staff to the location of 5 known tidal benchmarks that were set when the station was being set up as well.  As you can see, accounting for the tides is a complex process with multiple checks and double checks in place.  These checks may seem a bit much, but a lot of shifting and movement can occur in these areas.  Plus, these checks are the best way to ensure our data is accurate.

Micki and Adam setting up the staff, so they can make sure it hasn't moved.
ENS Micki and LTJG Adam setting up the staff, so the surveyor can make sure it hasn’t moved.

Mussels and barnacles on a rock in Terror Bay.
Mussels and barnacles on a rock in Terror Bay.

Leveling to ensure staff and tidal benchmarks haven't moved.
Leveling to ensure staff and tidal benchmarks haven’t moved.

 

 

 

 

 

 

 

 

Today, I went to shore again to a different area called Driver Bay.  This time we were taking down the equipment from a tidal gauge, because Rainier is quickly approaching the end of her 2014 season.  Driver Bay is a beautiful location, but the weather wasn’t quite as pretty as the location.  It snowed on our way in!  Junior Officer Micki Ream who has been doing this for a few years said this was the first time she’d experienced snow while going on a tidal launch.  Because of the wave action, this is a very dynamic area which means it changes a lot.

In fact, the staff that had been originally used to manually measure tides was completely gone, so we just needed to take down the tidal gauges, satellite antenna, solar panels, and orifice tubing.  The orifice itself was to be removed later by a dive team, because it is under water.  After completing the tidal gauge breakdown, we hopped back on the boat for a very bumpy ride back to Rainier.  I got a little water in my boots when I was hopping back aboard the smaller boat, but it wasn’t as cold as I had expected.  Fortunately, the boat has washers and driers.  It looks like tonight will be laundry night.

Raspberry Bay
Driver Bay

Personal Log 

The food here is great!  Last night we had spaghetti and meatballs, and they were phenomenal.  Every morning I get eggs cooked to order.  On top of that, there is dessert for every lunch and dinner!  Don’t judge me if I come back 10 lbs. heavier.  Another cool perk is that we get to see movies that are still in the theaters!  They order two movies a night that we can choose from.  Lastly, I haven’t gotten seasick.  Our transit from Seward to Kodiak was wavy, but I don’t think it was as bad as we were expecting.  The motion sickness medicines did the trick, because I didn’t feel sick at all.

Did You Know? 

NOAA (National Oceanic and Atmospheric Administration) contains several different branches including the National Weather Service which is responsible for forecasting weather and issuing weather alerts.

Animal Spotting

There are sea otters everywhere!

Sea otter (Enhydra lutris) sighting.
Sea otter (Enhydra lutris) sighting.

 

Lauren Wilmoth: Safety First, October 8, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Wednesday, October 8, 2014

Weather Data from the Bridge
Air Temperature: 3.82 °C
Wind Speed: 6.1 knots
Latitude: 60°07.098′ N
Longitude: 149°25.711′ W

Science and Technology Log

Junior Officer Micki Ream diving in Thumb's Cove.  Photo courtesy of Junior Officer Katrina Poremba.
Junior Officer Micki Ream diving in Thumb’s Cove. Photo courtesy of Junior Officer Katrina Poremba.

The launch that I participated in on Tuesday was awesome!  We went to an area called Thumb’s Cove.  I thought the divers must be crazy, because of how cold it was.  When they returned to the boat from their dive, they said the water was much warmer than the air.  The water temperature was around 10.5°C or 51°F while the air temperature was hovering right above freezing.  One diver, Katrina, took an underwater camera with her.  They saw jellyfish, sea urchins, and sea stars.

The ride to and from the cove was quite bouncy, but I enjoyed being part of this mini-adventure!  Later that day, we did what is called DC (Damage Control) familiarization.  Basically, we practiced what do in case of an emergency.  We were given a pipe with holes in it and told to patch it with various objects like wooden wedges.  We also practiced using a pump to pump water off of the ship if she were taking on water.  Safety drills are also routine around here.  It’s nice to know that everyone expects the best, but prepares for the worse.  I feel very safe aboard Rainier.

Seastar from Katrina Poremba from the dive at Thumb's Cove.
Sea star and anemones taken by diver Katrina Poremba at Thumb’s Cove.

This source diagram from Kodiak Island shows when the latest data was collected in for an area.  We will be working near the red x.
This source diagram from Kodiak Island shows when the latest data was collected in for an area. We will be working near the red x.

Today, I got a chance to meet with the CO (Commanding Officer), and he explained the navigational charts to me.  Before the ship leaves the port, there must be a navigation plan which shows not only the path the ship will take, but also the estimated time of arrival to various points along the way.  This plan is located on the computer, but also, it must be drawn on a paper chart for backup.

This illustrates again how redundancy, as I discussed in my last blog post, is a very important part of safety on a ship.  Every ship must have up-to-date paper charts on board.  These charts get updated with the information collected from the hydrographic surveys.  The ocean covers more than 70% of our planet which is why Rainier‘s mission of mapping the ocean is so important.  There are many areas in Alaska where the only data on the depth of the water was collected before sonar technology was used.  In fact, some places the data on the charts comes from Captain Cook in the 1700s!  If you look at the chart below the water depth is measured in fathoms.  A fathom is 6 feet deep.  Places that are less than 1 fathom deep have a 05 where the subscript indicates how deep the water is in feet.

TeacheratSea 066
One of the nautical charts that will help Rainier navigate back to its home port in Newport, Oregon. Notice the ocean depth marked in fathoms.

CO (Commanding Officer) and me after discussing nautical charts.
CO (Commanding Officer) and me after discussing nautical charts.

Today, I also spoke with the AFOO (Acting Field Operations Officer), Adam, about some work that he had been doing on Rainier‘s sister ship NOAA Fairweather.  One project they are working on is connecting hydrographic data to fish distribution and abundance mapping.  Basically, they want to find out if it is possible to use sonar data to predict what types of fish and how many you will find in a particular location

They believe this will work, because the sonar produces a back scatter signature that can give you an idea of the sea floor composition (i.e. what it is made of).  For instance, they could tell you if the sea floor is rocky, silty, or sandy using just sonar, as opposed to, manually taking a bottom sample.  If this hydrographic data is integrated with the data collected by other NOAA ships that use trawl nets to survey the fish in an area, this would allow NOAA to manage fisheries more efficiently.  For example, if you have map that tells you that an area is likely to have fish fry (young fish) of a vulnerable species, then NOAA might consider making this a protected area.

Personal Log

Artwork from the SeaLife Center created by high school students to illustrate how much trash ends up on our beaches.
Artwork from the SeaLife Center created by high school students to illustrate how much trash ends up on our beaches.

On Tuesday, I had a little extra time in the afternoon, so I decided to ride my bike down to the Alaska SeaLife Center which is a must-see if you ever find yourself in Seward.  There were Harbor Seals (Phoca vitulina), Stellar Sea Lions (Eumetopias jubatus), Puffins (Genus Fratercula), Pacific Salmon (Genus Oncorhynchus) and much more.  I really appreciated that the SeaLife Center focused on both conservation and on organisms that live in this area.  A local high school even had their art students make an exhibit out of trash found on the beach to highlight the major environmental issue of trash that finds its way to the ocean.

Can you think a project we could do that would highlight a main environmental concern in Eastern Tennessee?  I also thought is was really interesting to see the Puffins dive into the water.  The SeaLife Center exhibit explained about how Puffin bones are more dense than non-sea birds.  These higher density bones are an adaptation that helps them dive deeper.

Puffin at the Alaska SeaLife Center
Puffin at the Alaska SeaLife Center

I officially moved into the ship today.  Prior to that, I was staying at a hotel while they were finishing up repairs.  We are expected to get underway on Friday afternoon.  I am staying in the princess suite!  It is nice and cozy.  I have all of the essentials.  I have a desk, bunk beds, 2 closets, and one bathroom (head).

Rainier, my home for the next week and a half, in Seward Alaska
Rainier, my home for the next week and a half, in Seward, Alaska

My berthing area (where I sleep) nicknamed "The Princess Suite."
My berthing area (where I sleep) nicknamed “The Princess Suite.”

 

Did You Know? 

Junior Officers get homework assignments just like you.  At the navigation briefing today, the CO (Commanding Officer) told the Junior Officers what that they needed to review several documents before going through the inside passage (a particularly tricky area to navigate).  He is expecting them to lead different parts of the next navigation briefing, but he isn’t going to tell them which part they are leading until right before. Therefore, it is important that they know it all!  It’s a little like a pop quiz and presentation in one.

Word of the Day

Bathymetry – the study of the “beds” or “floors” of bodies of water.

Lauren Wilmoth: Introductions, October 7, 2014

NOAA Teacher at Sea
Lauren Wilmoth
Aboard NOAA Ship Rainier
October 4 – 17, 2014

Mission: Hydrographic Survey
Geographical area of cruise: Kodiak Island, Alaska
Date: Tuesday, October 7, 2014

Weather Data from the Bridge
Air Temperature: 0.77 °C
Wind Speed: 12 knots
Latitude: 60°07.098′ N
Longitude: 149°25.711′ W

Science and Technology Log

Our departure from Seward was originally scheduled for today, but the ship is having some repairs done, so our expected departure is now Wednesday or Thursday.  In case you were wondering, this doesn’t delay my return date.  Regardless of the fact that we are not underway, there is still so much to learn and do.

Yesterday, I met with Christie, one of the survey techs, and learned all about the Rainier’s mission.   The main mission of the ship is to update nautical charts.  Up-to-date charts are crucial for safe navigation.  The amount of data collected by Rainier if vast, so although the main mission of the Rainier is updating nautical charts, the data are also sent to other organizations who use the data for a wide variety of purposes.  The data have been used for marine life habitat mapping, sediment distribution, and sea level rise/climate change modeling among other things.  In addition to all of that, Rainier and her crew sometimes find shipwrecks.  In fact, Rainier and her crew have found 5 shipwrecks this season!

 

This is what a shipwreck looks like to the sonar. This is a picture of a shipwreck found by another NOAA hydrographic ship. Photo courtesy of NOAA.

 

Simplified, hydrographic research involves sending multiple sonar (sound) beams to the ocean floor and recording how long it takes for the sound to come back.  You can use a simple formula of distance=velocity/time and divide that by two because the sound has to go to the floor and back to get an idea how deep the ocean is at a particular spot.  This technique would be fine by itself if the water level weren’t constantly fluctuating due to tides, high or low pressure weather systems, as well as, the tilt of the ship on the waves.  Also, the sound travels at different speeds according to the water’s temperature, conductivity and depth.  Because of this, the data must be corrected for all of these factors.  Only with data from all of these aspects can we start to map the ocean floor.  I have attached some pictures of what data would look like before and after correction for tides.

 

This shows the advantages of using multibeam sonar to complete surveys. Photo courtesy of NOAA.

Hydrographic data with correction for tides.  Photo courtesy of Christie.
Hydrographic data with correction for tides. Photo courtesy of Christie.

Hydrographic data without correction for tides.  Photo courtesy of Christie
Hydrographic data without correction for tides. Photo courtesy of Christie

I was also given a tour of the engine room yesterday.  Thanks, William.  He explained to me how the ship was like its own city.  In this city, there is a gym, the mess (where you eat), waste water treatment, a potable (drinkable) water production machine, and two engines that are the same type of engines as train engines.  Many of my students were interested in what happens to our waste when we are aboard the ship.  Does it just get dumped into the ocean?  The answer is no.  Thank goodness!  The waste water is exposed to bacteria that break down the waste  Then, salt water is used to produce chlorine that further sterilizes the waste.  After those two steps, the waste water can be dumped.  The drinking water is created by evaporating the water (but not the salt) from salt water.  The heat for this process is heat produced by the engine.  William also explained that there are two of everything, so if something fails, we’ll still be alright.

Me working out at the Rainier gym.
Rainier’s gym

Rainier's back-up generator.
Rainier’s back-up generator 

Personal Log

Sunday, I drove from Anchorage to Seward.  The drive was so beautiful!  At first, I was surrounded by huge mountains that were vibrant yellow from the trees whose leaves were turning.  Then, there was snow!  It was actually perfect, because the temperature was at just the right point where the snow was melted on the road, but it had blanketed the trees.  Alaska is as beautiful as all of the pictures you see.  The drive should have been about 2.5 hours, but it took me 3.5 hours, because behind each turn the view was better than the previous turn, so I had to stop and take pictures.  I took over 100 pictures on that drive.  Once I arrived in Seward, I was given my first tour of the ship and then I had some time to explore Seward.

TeacheratSea 074
One of the views on my drive from Anchorage to Seward

 

Trying on my survival (gumby) suit
Trying on my survival (gumby) suit

Yesterday (the first official day on the job), I learned so much.  Getting used to the terminology is the hardest part.  There are acronyms from everything!  Immersion is the best way to learn a foreign language, and I have been immersed in the NOAA (National Oceanic and Atmospheric Administration) language.  There is the CO (Commanding Officer), XO (Executive Officer), FOO (Field Operations Officer), TAS (Teacher at Sea or Me!), POD (Plan of the Day) and that is just the tip of the iceberg.  I also had to learn all of the safety procedures.  This involved me getting into my bright red survival suit and learning how to release a lifeboat.

Today, I am going on a dive launch.  The purpose of this launch is to help some of the divers get more experience in the cold Alaskan waters.  I will get to ride on one of the smaller boats and watch as the Junior Officers scuba dive.

Did You Know? 

NOAA Corps is one of the 7 branches of the U.S. uniformed services along with the Army, Navy, Coast Guard, Marine Corps, Air Force, and the Public Health Service Commissioned Corps (PHSCC).

Emina Mesanovic, Acoustic Lab: Let’s Make Some Maps, July 28, 2014

NOAA Teacher at Sea

Emina Mesanovic

Aboard the NOAA Ship Pisces

July 20 – August 2, 2014

 Mission: Southeast Fishery- Independent Survey

Geographic area of the cruise: Atlantic Ocean, off the coast of North Carolina and South Carolina

Date: July 28, 2014

Weather Information from the Bridge

Air Temperature: 27.5 C

Relative Humidity: 86%

Wind Speed: 15.03 knots

 Science and Technology Log

There is a lot of work that goes into allowing the fishery team to be able to set traps every day. The acoustics lab/ night shift is responsible for creating the maps of the seafloor that will be used the following day. The team consists of David Berrane a NOAA fisheries biologist, Erik Ebert a NOAA research technician, Dawn Glasgow from the South Carolina Department of Natural Resources and a Ph.D student at the University of South Carolina, as well as Mary a college student studying Geology at the College of Charleston and Chrissy a masters student at the University of South Carolina. This team is amazing! Starting at around 5:00 pm the day before they stay up all night mapping the ocean floor.

The night shift working together
The night shift collecting data

Every night Zeb Schobernd lets the night shift know which boxes they will work on. These boxes are created in the offseason by the research scientists, they base their selection on information from fishermen, the proximity to already mapped areas, weather and previous experiences. The first step in creating a bathymetric map is to create a line plan, which lets the ship know which area will be covered. The average line takes about half an hour to complete but they can take up to several hours. The ship drives along these lines all night long while the team uses the information that is gathered to create their maps.

So how do they get this information? The ship uses sonar to collect data on the water column and the ocean floor. The Pisces has a 26 multi-beams sonar system, which allows the research team to create a better picture, compared to using single beam sonar. The beams width is about 3 times the depth of water column. This means that depending on how deep the water is in any given location, it will determine how many lines need to be run to cover the area.

Multibeam sonar
Multi-beam sonar (picture from NOAA)

The picture below is one of the computer screens that the scientists look at throughout the night. It provides the sonar information that will then be used to map the floor. Sonar works by putting a known amount of sound into the water and measuring the intensity of the return. A rock bottom will yield a stronger return while a sand bottom will absorb the sound and yield a less intense return. In the image red means that there is a more intense return while blue and yellow signifies a less intense return. You will notice in the center screen there is a strong red return at the top of the beam this is because the ship is sending out the sound and it takes about four meters until you start recording information from the sea floor.

SIMRAD70 (multi-beam sonar)
SIMRAD (multi-beam sonar)

Finally before the maps can be created the team has to launch an XBT (expendable bathy thermograph) two times per box or every four hours. The XBT measures the temperature and conductivity of the water, this is important because sound travels at different rates in cold versus warm water. This information is then used when the scientists calculate the sound velocity, which is used to estimate the absorption coefficient of sound traveling through the water column.

 

Once the data is collected the team begins the editing process. First they have to remove random erroneous soundings in order to get an accurate map; they fondly call this process dot killing (this basically means getting rid of outliers). They do this by drawing a box around the points of data they want to remove and deleting the point. Next they apply tide data to account for the deviations in the tides, this information is obtained from NOAA and is based on the predicted tides for the area. Finally they apply the sound absorption coefficient.

Editing the data (killing dots)
Editing the data (killing dots)

The final product is put into GIS (Geographic Information Systems), which the chief scientists will use to determine where the traps should be set the following morning. On the map below blue indicates the deepest areas while red shows the shallowest. The scientists want to place the traps in areas where there is a large change in depths because this is usually where you will find hard bottoms and good fish habitats.

Finished map (red shallow, blue deep)
Finished map

Personal Log

I have spent the past three nights in the Acoustics/Computer Lab with the night shift mapping the ocean floor. While the ship sails along the plotted course, I have had the opportunity to see the sunrise and sunset on the Pisces as well as a lightning storm from the top deck.

images
Lighting on the ocean (picture from sciencedaily)

On Thursday night a little after midnight after launching the XBT we see decided to go onto the top deck of the Pisces to get a better look at the lighting storm in the distance. Even at night it was still humid and hot and as we climbed up to the top deck it was dark all around us until suddenly there would be a flash of color in the clouds and you could see everything, until it went dark again. We tried to take a picture but the lightening was just too fast for our cameras. This is the closest picture I could find to what it was like that night except the water was not calm.

 

SPOTLIGHT ON SCIENCE

Name: Erik Ebert                  Title: Research Technician

Erik editing data collected on Sunday July 26th.
Erik editing data collected on Sunday July 26th.

Education: Cape Fear Tech (Wilmington, NC)

How long have you worked for NOAA/NOS: 6th field season, 5th year

Job Summary: I work on ecosystem assessments throughout the Gulf of Mexico South Atlantic & Caribbean

– Team oriented production of ocean floor maps

– System setup & keeping the acoustic systems operating correctly

How long have you participated in this survey: Since 2010

What do you like about your job: That the data we collect, and the maps we create can be used again for different studies. The types of data we collect includes bathymetric data, information on the water column, & fish that populate the water column.

How many days are you at sea: 60 days (April-November)

What do you do when you are not on the boat: Process & produce fish density maps from the data collected during the cruises. I also work for National Ocean Services (provide data to policy & decision makers to the state of the ecosystem)

Most challenging about research on a ship: Being away from home is the biggest challenge.

What would be your ideal research cruise: My ideal research cruise would be a cruise similar to what we just completed in Flower Garden Banks in the Gulf of Mexico. It was a 3-year assessment of the reef ecosystem using ROV, Diving and Acoustics to study how the ecosystem changed over time.

Favorite fish: Trigger Fish “cool swimming behavior”

More information about See Floor Mapping   http://www.noaa.gov/features/monitoring_1008/seafloormapping.html

COOL CATCH

Crab with three sea anemones attached to its shell
Crab with three sea anemones attached to its shell

Kevin McMahon: Midnight Mapping! July 13, 2014

NOAA Teacher at Sea

Kevin McMahon

Aboard the NOAA ship Pisces

July 5 – July 18, 2014

 

Mission: Southeast Fisheries Independent Survey

Geographic area of the cruise: Atlantic Ocean, off the coast of North Carolina and South Carolina

Date: July 13, 2014

Weather Information from the Bridge

Air Temperature:            27.6 °C

Relative Humidity:         73%

Wind Speed:                  5.04 knots

 

Science and Technology Log

Someone is always working on the Pisces. When Nate Bacheler and the other fishery scientists have finished their work for the day collecting fish, it is show time for the hydrographers, the scientists who map and study the ocean floor. Their job is to map the ocean floor to help Nate find the best places to find fish for the next day.  Warren, Laura, David and Matt were kind enough to let me join them and explained how they map the ocean floor while on board the Pisces.

People have learned over the years that some fish like to hang out where there is a hard bottom, not a sandy bottom. These hard bottom areas are where coral and sponges can grow and it also happens to be where we usually find the most fish.

Instead of using a camera to find these hard bottom habitats, the mapping scientists use multibeam sonar. Here is a simple explanation on how sonar works. The ship sends a sound wave to the bottom of the ocean. When the sound wave hits the bottom, the sound bounces back up to the ship.

Since scientists know how fast sound travels in water, they can figure out how far it is to the ocean floor. If the sound wave bounces back quickly, we are close to the ocean floor. If the sound wave takes longer, the ocean floor is farther away. They can use this data to make a map of what the ocean floor looks like beneath the ship.

The neat thing about the Pisces is that it does not send down one sound wave only. It sends 70 waves at once. This is called multibeam sonar.

Single Beam versus Multibeam sonar.  Can you see why scientists like to use multibeam sonar?
Single Beam versus Multibeam sonar. Can you see why hydrographers like to use multibeam sonar? Credit: NOAA

So, now you know how sonar works in simple terms.

But it gets a little more complicated. Did you know that sound speed can be affected by the water temperature, by how salty the water is (the “salinity”), by tides, and by the motion of the ship?  Computers make corrections for all of these factors to help get a better picture of the ocean floor. But, computers don’t know the physical properties of our part of the ocean (because these properties change all the time) so we need to find this information and give it to the computer.

To find the temperature of the ocean water, the mapping scientists launch an “XBT” into the water.  XBT stands for “expendable bathythermograph.”  The XBT records the changes in water temperature as it travels to the ocean floor.  It looks like a missile.  It gets put into a launcher and it has a firing pin. It sounds pretty dangerous, doesn’t it!  I was excited to be able to fire it into the water.  But, when I pulled out the firing pin, the XBT just gently slid out of the launcher, softly plopped into the ocean, and quietly collected data all the way to the ocean floor.

 

Kevin McMahon nervously holding the XBT Launcher and waiting for the order to fire.
Kevin McMahon nervously holding the XBT Launcher and waiting for the order to fire.

                 

Kevin McMahon watches as the XBT gently plops out of the launcher.
Kevin McMahon watches as the XBT gently plops out of the launcher.

 

With the new data on water temperature, the hydrographers were able to create this map of the ocean floor.

Example of an Ocean Floor Map
Example of an Ocean Floor Map

 

In the map above, blue indicates that part of the ocean floor that is the deepest. The green color indicates the part of the map that is the next deepest. The red indicates the area that is most shallow.

Nate talks to the hydrographers early in the morning and then predicts where the hard bottom habitats might be. In particular, Nate looks for areas that have a sudden change in elevation, indicating a ledge feature.  If you had Nate’s job, where would you drop the 6 traps to find the most fish?  Look at the map below to see where Nate decided to deploy the traps.

 

The green dots are the spots where Nate dropped the traps in hopes of finding fish.
The green dots are the spots where Nate dropped the traps in hopes of finding fish.

 

To find out more about using sound to see the ocean floor and to see an animation of how this works, click on this link:

 NOAA: Seeing the Ocean Floor

               

Personal Log

 

We have now gotten into a regular routine on the ship.   The best part of the day for me is when we are retrieving the traps. We never know what we will see. Sometimes we catch nothing. Sometimes we find some really amazing things.

 

Here are a few of my favorites:

 

Closer view of sharksucker on my arm
Closer view of sharksucker on my arm

 

Somebody is crabby.
Somebody is crabby.

 

Sea stars with beautiful navy blue colors
Sea stars with beautiful navy blue colors

 

A pair of butterflyfish
A pair of butterflyfish

 

Did you know?

The ocean is largely unexplored.  Maybe someday you will discover something new about the ocean!

 

Mary Murrian: My First Days in Dutch Harbor, July 6, 2014

NOAA Teacher at Sea 

Mary Murrian

Aboard NOAA Ship Oscar Dyson

July 4 – 22, 2014

Mission: Annual Walleye Pollock Survey

Geographical Area of Cruise: Bering Sea North of Dutch Harbor

Date: Sunday, July 6th, 2014

Weather Data from the Bridge:

Wind Speed: 6 kts

Air Temperature: 8.6 degrees Celsius

Weather conditions: Hazy

Barometric Pressure: 1009.9

Latitude: 5923.6198  N

Longitude: 17030.6395  W

 

Science and Technology Log

Part One of the Survey Trawl: Getting Ready to Fish

This is a picture of a pollock from our first trawl.
This is a picture of a pollock from our first trawl.

Today is my second day aboard the Oscar Dyson.  We are anxiously waiting for the echosounder (more information on echosounder follows) to send us a visual indication that a large abundance of fish is ready to be caught.  The point of the survey is to measure the abundance of Walleye Pollock throughout specific regions in the Bering Sea and manage the fisheries that harvest these fish for commercial use to process and sell across the world.  The Walleye Pollock are one of the largest populations of fish.  It is important to manage their populations due to over-fishing could cause a substantial decrease the species.  This would be detrimental to our ecosystem.  The food web [interconnecting food chains; i.e. Sun, plants or producers (algae), primary consumers, animals that eat plants (zooplankton), secondary consumers, animals that eat other animals (pollock), and decomposers, plants or animals that break down dead matter (bacteria)] could be altered and would cause a negative effect on other producers and consumers that depend on the pollock for food or maintain their population.

The main food source for young pollock is copepods, a very small marine animal (it looks like a grain of rice with handle bars).  They also eat zooplankton (animals in the plankton), crustaceans, and other bottom dwelling sea life.  On the weird side of the species, adult pollock are known to eat smaller pollock.  That’s right, they eat each other, otherwise known as cannibalism.  Pollock is one of the main food sources for young fur seal pups and other marine life in Alaskan waters.  Without the pollock, the food web would be greatly altered and not in a positive way.

How do we track the pollock?

Pollock
Pollock

Tracking begins in the acoustics lab.  Acoustics is the branch of science concerned with the properties of sound.  The acoustics lab on board the Oscar Dyson, is the main work room where scientists can monitor life in the ocean using an echosounder which measures how many fish there are with sound to track the walleye pollock’s location in the ocean.  They also use the ships’s GPS (Global Positioning System), a navigation system, to track the location of the NOAA vessel and trawl path.

Echo Sounder
Sonar Screen

What is sonar and how does it work? 

Sonar (sound ranging & navigation;  it’s a product of World War II) allows scientists to “see” things in the ocean using sound by measuring the amount of sound bouncing off of objects in the water.  On this survey, sonar images are displayed as colors on several computer monitors, which are used to see when fish are present and their abundance.  Strong echoes show up as red, and weak echoes are shown as white.  The greater the amount of sound reported by the sonar as red signals, the greater the amount of fish.

Echo Sonar Screen Showing the patterns of echos from the ocean.
Echo Sonar Screen Showing the patterns of echos from the ocean.

How does it work?  There is a piece of equipment attached to the bottom of the ship called the echosounder.  It sends pings (sound pulses) to the bottom of the ocean and measures how much sound bounces back to track possible fish locations.   The echo from the ocean floor shows up as a very strong red signal.   When echoes appear before the sound hits the ocean floor, this represents the ping colliding with an object in the water such as a fish.

The scientists monitor the echosounder signal so they can convey to the ships’s bridge and commanding officer to release the nets so that they can identify the animals reflecting the sound.  The net catches anything in its path such as jellyfish, star fish, crabs, snails, clams, and a variety of other fish species. Years of experience allows the NOAA scientists the ability to distinguish between the colors represented on the computer monitor and determine which markings represent pollock versus krill or other sea life.  We also measure the echoes at different frequencies and can tell whether we have located fish such as pollock, or smaller aquatic life (zooplankton). The red color shown on the sonar screen is also an indicator of pollock, which form dense schools.  The greater amount of red color shown on the sonar monitor, the better opportunity to we have to catch a larger sample of pollock.

The Science Team Wonderful group of people.

Once we have located the pollock and the net is ready, it is time to fish.  It is not as easy as you think, although the deck hands and surveyors make it look simple.  In order to survey the pollock, we have to trawl the ocean.  Depending on the sonar location of the pollock, the trawl can gather fish from the bottom of floor, middle level and/or surface of the ocean covering preplanned locations or coordinates. Note: Not all the fish caught are pollock.

The preplanned survey path is called transect lines with head due north for a certain distance. When the path turns at a 90 degree angle west (called cross-transect lines) and turns around another 90 degree angle heading back south again.  This is repeated numerous times over the course of each leg in order to cover a greater area of the ocean floor.  In my case we are navigating the Bering Sea.  My voyage, on the Oscar Dyson is actually the second leg of the survey, in which, scientists are trawling for walleye pollock.  There are a total of three legs planned covering a distance of approximately 6,200nmi (nautical miles, that is).

Trawling is where we release a large net into the sea located on the stern (the back of the boat).  Trawling is similar to herding sheep.  The fish swim into the net as the boat continues to move forward, eventually moving to the smaller end of the net.  Once the sonar screen (located on a computer monitor) shows that we have collected a large enough sample of pollock, the deck hands reel the net back on board the boat.

 

The crew are beginning to release the trawl net.
The crew are beginning to release the trawl net.

This is the stern of the boat where the trawl net gets released into the ocean.
This is the stern of the boat where the trawl net gets released into the ocean.

We have caught the fish, now what?  Stay tuned for my exciting experience in the wet lab handling the pollock and other marine wild life.  It is most certainly an opportunity of a lifetime.

Personal Log

What an adventure!

I was lucky enough to spend a day exploring Dutch Harbor, Alaska before departing on the pollock survey across the Bering Sea. It took me three plane rides, several short lay-overs and and a car ride to get here, a total of 16 hours. There is a four hour time difference between Dutch Harbor and Dover, Delaware. It takes some getting used to, but definitely worth it. The sun sets shortly after 12:00 midnight and appears again around 5:00 in the morning. Going to sleep when it’s still daylight can be tricky. Thank goodness I have a curtain surrounding my bed. Speaking of the bed, it is extremely comfortable. It is one of those soft pillow top beds. Getting in and out of the top bunk can be challenging. I haven’t fallen yet.

My bed is the top bunk.
My bed is the top bunk.

During my tour through the small town of Dutch Harbor, I have encountered very friendly residents and fishermen from around the world.  I was fortunate to see the U.S. Coast Guard ship Healy docked at the harbor. What a beautiful vessel.  Dutch Harbor has one full grocery store (Safeway) just like we have in Delaware, with the exception of some of the local Alaska food products like Alaska BBQ potato chips. They have a merchant store that sells a variety of items ranging from food, souvenirs, clothing, and hardware. They have three local restaurants and a mom and pop fast food establishment. One of the restaurants is located in the only local Inn the Aleutian hotel, which also includes a gift shop. Dutch Harbor is home to several major fisheries. Dutch Harbor is rich in history and is home to the native Aleutian tribe. I took a tour of their local museum. It was filled with the history and journey of the Aleutian people. While driving through town, I got a chance to see their elementary and high school. They both looked relatively new. Dutch Harbor is also home to our nation’s first Russian Orthodox Church. Alaska is our 50th state and was purchased from Russia in 1867.

Me and the Oscar Dyson
Mary Murian in front of the Oscar Dyson

A very funny photo of me in my survival suit.
A very funny photo of me in my survival suit.

One of the coolest parts of my tour was walking around the area known as the “spit”. The “spit” is located directly behind the airport. I’m told it is called the “spit” because the land and water are spitting distance in length and width. We walked along the shoreline and discovered hundreds of small snails gathered around the rocks. We also found hermit crabs, starfish, sea anemones, jellyfish, and red algae. We saw red colored water, which is a bloom or a population explosion of tiny algae that get so thick that they change the color of the water.

One of numerous amazing views in Dutch Harbor
One of numerous amazing views in Dutch Harbor

tas 2014 day 1 and perboarding july 2-4th 089
Starfish

Another animal in abundance in Dutch Harbor is the bald eagle. There is practically one on every light post or tall structure. Often the bald eagles are perched in small groups. Watch out: if you walk too close to a nesting mother, she will come after you. They are massive, regal animals. I never get tired of watching them.

We had to watch our step, the snails were everywhere along the shoreline of the Spit.
We had to watch our step, the snails were everywhere along the shoreline of the Spit.

A bald eagle hoping to find some lunch.
A bald eagle hoping to find some lunch.

Russian Orthodox Church in Dutch Harbor, AK
Russian Orthodox Church in Dutch Harbor, AK

Did You Know?

Did you know that Alaska’s United States Coast Guard vessel has the ability to break through sea ice? 

This is especially helpful if you want to study northern areas, which are often ice covered, in the winter, and to assist a smaller boat if it gets trapped in the ice.

U.S. Coast Guard Ship Healy docked at the Spit.
U.S. Coast Guard Ship Healy docked at the Spit.

Did you know that scientists set time to Greenwich Mean Time (GMT) which is the time in a place in England?

This reduces confusion (e.g. related to daylight savings, time zones) when the measurements are analyzed.

Key Vocabulary:

Carnivore

Primary Consumer

Secondary Consumer

Nautical Miles

Trawling

Stern

Acoustics

Decomposers

Echosounder

Meet the Scientist:

Alex De Biologist
Alex De Robertis Chief Scientist

Leg II Chief Scientist Dr. Alex De Robertis

Title: NOAA Research Fishery Biologist (10 years)

Education:  UCLA Biology Undergraduate Degree

Scripps Institute Oceanography San Diego, CA PhD.

Newport, Oregon Post Doctorate work

Living Quarters:

Born in Argentina and moved to England when one-year old.

Lived in Switzerland and moved to Los Angeles,CA at the age of 13.

Currently lives in Seattle, Washington, and he has two kids aged one and five.

Job Responsibilities:

Responsible for acoustic trawl surveying at Alaska Fisheries Science Center

Was able to help with the Gulf of Mexico oil spill clean-up using the same echo sonar used on trawl surveys.

What is cool about his work:

He enjoys his work, especially the chance to travel to different geographic locations and meet new people.  “You never know what you are going to encounter; there is always a surprise or curve ball, when that occurs you adjust and just go with it”.

In the near future, he would love to see or be part of the design for an autonomous ocean robot that will simplify the surveying process.

He has been interested in oceans and biology since a small boy.  He remembers seeing two divers emerge from the sea and was amazed it was possible.

Dave Murk: Three 2’s From the Okeanos Explorer, May 10, 2014

NOAA Teacher at Sea
Dave Murk
Aboard NOAA Ship Okeanos Explorer
May 7 – 22, 2014

Mission: EX 14-03 – Exploration, East Coast Mapping
Geographical Area of Cruise: Off the Coast of Florida and Georgia – Western portion of the Blake Plateau (Stetson Mesa)
Date: May 10, 2014

Weather data from Bridge:
Temperature 25 degrees celsius (can you convert to Fahrenheit?)
WInd – From 160 degrees at 14 knots (remember north is 0 degrees)
Latitude : 28 degrees  – Longitude: 79 degrees.

 

Science and Technolgy Log:

Two of the goals for this expedition. (There are a lot more)

Expedition coordinator Derek Sowers said his best case scenario for this mission is to meet all the cruise objectives. The main one- an aggressive 24/7 campaign to map as much seafloor as possible within top priority mapping areas offshore of the Southeast United States and along the canyons at the edge of the Atlantic continental shelf.

L – R – Chief Scientist Derek Sowers, Vanessa Self-Miller, Kalina Grabb

In addition to that mapping goal, he wants the visiting fisheries scientist on board to get good water samples for the Ocean Acidification Program and good samples from the plankton tows. Last but not least, he “wants the mission team to have a great learning experience.”

The ship has three different sonars, each of which is good for different things. One sonar sends out a single beam of sound that lets you see fish and other creatures in the water column. Another sonar sends powerful sounds that bounce back off the bottom and gives you information about the geology (rocks and sediment) of the seafloor. Perhaps the most impressive sonar onboard is the multi-beam sonar. You know how your garden hose has a setting for jet spray when you want to aim it at your brother who is 10 feet away? The water comes out in a straight narrow line. But there’s also another setting called ‘shower” or wide spray. The multibeam sonar is like combining the best of both of these sprays into one and sends out a fan of sound that allows the scientists to map a broad section of the seafloor. By measuring how long it takes this sound to reach a patch of seafloor and return to the ship, it is possible to estimate the distance and that is how the shape of the seafloor can be mapped. Using this technology enables NOAA to map the seascape in order to better protect marine habitat and reduce harm from human activities. Mapping the marine protected areas off the east coast of Florida and Georgia is important because there are deep sea corals in this area and it is important fisheries habitat.

Chris Taylor – NOAA Fisheries

This cruise features a visiting scientist from NOAA Fisheries, named Chris Taylor. Chris’s part of the expedition includes collecting water samples and towing a net that can collect very small creatures called plankton. Chris is specifically examining the plankton he catches to see if bluefin tuna use this part of the ocean to lay eggs and raise young tuna. Samples from the net will go back to a lab to be analyzed to make sure they are bluefin and not yellowfin tuna.

Chris spent most of this windy but warm night tying a rope to the net that he’ll use for HOPEFULLY – catching some baby Bluefin Tunas. Like insects, Bluefin tuna go through an egg stage THEN a larva stage. When they are very small they drift with the currents with the rest of the ocean community. Once a larva is over 7 millimeters, they can avoid the net. But If we find some Bluefin tuna – it may mean that we have found a new spawning ground for Bluefin tuna in the southern North Atlantic.

Personal Log:

Lt. Emily Rose instructs AB Tepper-Rasmussen in radar navigation techniques.

Two people who make this ship run so well:The operations officer – Lieutenant Emily Rose. Officer Rose can usually be found on the bridge of the NOAA ship Okeanos Explorer. Today she was teaching a course on small craft navigation before I caught up with her. The thing she really loves about this position is that there are new set of challenges each day. She is always learning (and I’ll add that she is almost always sharing that knowledge with others) but the ship is her first responsibility. The most difficult thing is getting up every morning before 3:00 a.m. and being away from everyone back home.

 

 

Electronics Technicians Conway and Okeson

Chief Electronics Technician Richard Conway and Electronics Technician Will Okeson are the Tech guys and they are always busy. Since Okeanos Explorer is America’s premier ocean exploration ship, there are a lot of computers, miles of cable and lots of video equipment to maintain. Richard and Will’s favorite part of the job is when all the parts work together and the public can see their product and when they can trouble shoot and help the science team reach their objectives. The most difficult thing it so be away from families when there is a crisis or joyous moment.

Two things about my personal experiences so far on EX-14-03 (our mission)

Using photometer to monitor aerosol properties. (photo taken by Mapping Intern Kalina Grabb
Using photometer to monitor aerosol properties. (photo taken by Mapping Intern Kalina Grabb

First – – “SCIENCE RULES” to quote Bill Nye. Every Okeanos Explorer crew member and scientific crew member are all about the science of the mission. When one of the science crew is going to launch something called an XBT over the side, they call and get an OK from the bridge (where the captain or second in command and the crew that are on “watch” are located). No one hesitates to ask questions of each other. Why is this? What is that? Where is the nearest ship? What’s for lunch? (just kidding ! Chief Steward Randy posts a menu every day and it beats out Golden Corral any day of the week for tastiness and diversity). But the important thing of the mission is the science and every single person on the ship works to make the mission a success.

Second – RESPECT – There is so much respect shown on the Okeanos Explorer. It’s respect for other people, for the ship, for the environment, for rules and for commons spaces.  Yesterday while on the bridge, Ensign Nick Pawlenko was taking over from Commander Ramos and they both showed such respect for rules and for each other by going over all the observations of the ship’s speed, the weather conditions and whether there were any other ships in the area.  When breakfast was over – I saw Operations Officer Rose stick her head in the galley (kitchen) and thank Chief Cook Ray and Chief Steward Randy for a great meal. No one slams doors since it might wake the crew and scientists who are on night duty. Everyone cleans up after themselves. If you ever have a question and if the crew or scientists can answer it, they will. There is respect for the environment when we separate our garbage each meal.   If only the whole world was like the Okeanos.

 

MYSTERY PICTURE – Here are two photos – what’s different about them? And WHY?? That’s the million dollar question (or an even better prize –bluefin tuna larva in our trawl nets )

IN the mess (dining area)

(see anything different?)
(see anything different?)

 

 

 

 

 

 

 

 

Susy Ellison, A Hydrographic Wonderland, September 13, 2013

NOAA Teacher at Sea
Susy Ellison
Aboard NOAA Ship Rainier
September 9-26, 2013

Mission:  Hydrographic Survey
Geographic Area: South Alaska Peninsula and Shumagin Islands
Date:  September 13, 2013

Weather:  current conditions from the bridge
You can also go to NOAA’s Shiptracker (http://shiptracker.noaa.gov/) to see where we are and what weather conditions we are experiencing
GPS Reading:  55o 15.037’ N  162o 38.025’ W
Temp: 10.44C
Wind Speed: 9.8 kts
Barometer: 1021.21 mb
Visibility:  foggy on shore

Science and Technology Log

Since leaving Kodiak 5 days ago, I have been immersed in a hydrographic wonderland.  Here’s what I’ve learned, summed up in two words (three, if you count the contraction); it’s complicated.  Think about it.  If I asked you to make a map of the surface of your desk you could, with a little bit of work and a meter stick, make a reasonably accurate representational diagram or map of that surface that would include the flat surface, as well as outlines of each item on the surface and their heights relative to that surface, as well as their location relative to each other on a horizontal plane.  You might want to get fancy and add notes about the type of surface (is it wood, metal, or some sort of plastic), any small irregularities in that surface (are there some holes or deep scratches—how big and how deep?), and information about the types of objects on the desk top (are they soft and squishy, do they change location?).  Now, visualize making this same map if your desktop was underwater and you were unable to actually see it.   Not only that, the depth of the water over your desktop can change 2 times each day.  If that isn’t complicated enough, visualize that the top of the water column over your desk is in constant motion.  OK, not only all those variables, but pretend you are transformed into a very teeny person in a small, floating object on that uncertain water over the top of your desk trying to figure out how to ‘see’ that desktop that you can’t actually see with your own eyes?  Welcome to the world of the hydrographer; the challenge of mapping the seafloor without actually touching it.  It is, indeed, a complex meld of science, technology, engineering, and math (STEM, in educational parlance), as well as a bit of magic (in my mind).

How do you know what's down there?
How do you know what’s down there?

Challenge number one—how do you measure something you can’t see or touch with your own hands?  Long ago, sailors solved that obstacle by using a lead line; literally, a line with a lead weight attached to the end.  They would drop the weighted line over the side of their ship to measure the depth.  These soundings would be repeated to get enough data to provide a view of the bottom.  This information was added to their maps along with estimates of the horizontal aspects (shoreline features and distance from the shoreline) to create reasonably good charts that kept them off most of the underwater obstacles. A simple solution to a complex problem.  No electricity required, no advanced degrees in computer science needed, no calculus-based physics necessary.  Fast- forward to 2013 and the world of complex calculations made possible by a variety of computer-based algorithmic calculations (i.e. some darn fancy computing power that does the math for you). The NOAA Ship Rainier’s hydrographers use sound as their lead line, traveling in small boats known as launches that are equipped with multibeam sonar that send a series of sound ‘pings’ to the ocean floor and measures the time between sending and receiving the ping back after its trip to the bottom.  Sounds simple enough, doesn’t it?  If it were all that simple I wouldn’t be typing this in a room on the Rainier filled with 20 computer monitors, 10 hard drives, and all sorts of other humming and whirring electronic devices.  Not only that, each launch is equipped with its own impressive array of computer hardware.

One of the launches is lowered from the ship.
One of the launches is lowered from the ship.

So far on our survey days 2 launches have been sent out to cover identified transects.  Their onboard crew includes a coxswain (boat driver), as well as 2-3 survey technicians and assistants. Each launch is assigned a polygon to survey for the day.

EVERY PING YOU TAKE…

Once they arrive at their assigned area, it’s time to ‘mow the lawn’—traverse back and forth systematically collecting data from one edge of your assigned polygon to the other until the entire area has been surveyed. Just in case you haven’t realized it yet, although that sounds pretty straightforward, it isn’t. Is the area shallow or deep?  Depth affects how much area each traverse can cover; the sonar spreads out as it goes downward sending it’s little pings scampering to the ocean floor. Visualize an inverted ‘V’ of pings racing away from the sonar towards the sea floor. If it’s deep, the pings travel further before being bounced back upwards.  This means that the width of each row the sonar cuts as it “mows the lawn” is wider in deeper water, and narrower in shallow.  Shallower areas require more passes with the launch, since each pass covers a more limited area than it might if the water were deeper.  As the launch motors back and forth ‘mowing the lawn’, the sonar  signature is recorded and displayed on monitors in the cabin area and in front of the driver.  Ideally, each lap overlaps the previous one by 25-50%, so that good coverage is ensured.  This requires a steady hand and expert driving skills as you motor along either over or parallel to ocean swells.  All you video gamers out there, take note–add boat driving to the repertoire of skills you might need if you want to find a job that incorporates video gaming with science!

sonar screen
One of the monitors displays the sonar. The green line is the seafloor. This image shows that the deeper the sea, the wider the swath that is covered with each pass of the launch.

Calvin Burch uses a computer monitor to guide him as he drives the launch.  It's an art to 'mow' in straight lines while anticipating every roll and bounce of the coean's surface.
Calvin Burch uses a computer monitor to guide him as he drives the launch. It’s an art to ‘mow’ in straight lines while anticipating every roll and bounce of the ocean’s surface.

Here’s a small list of some of the variables that need to be considered when using sonar to calculate depth; the chemistry of the water column through which you are measuring, the variability of the water column’s depth at specific times of day, the general depth (is it shallow or deep), and the movement of the measuring device itself.  So many variables!!

Starla Robinson and Randy Shingeldecker monitor our progress on the launch's computer monitors.
Starla Robinson and Randy Shingledecker set up the program that will enable them to monitor our progress

HOW FAST DOES SOUND TRAVEL?

When you’re basing your charts on how sound travels through the water column, you need to look at the specific characteristics of that water.  In a ‘perfect world’, sound travels at 1500m/second through water.  In our real world, that speed is affected by salinity (the concentration of salts), temperature, and depth (water pressure).  The survey crew uses a CTD meter to measure Conductivity, Temperature, and Depth.  The CTD meter is deployed multiple times during the day to obtain data on these parameters.  It is attached to a line on the rear of the launch, dropped into the water just below the surface for 2 minutes, and then lowered to near the ocean floor to collect data.  After retrieval, it’s hooked to the computer on the launch to download the data that was collected.  That data is stored in its own file to use when the data is reviewed in the evening back on board the Rainier.  This is one of the variables that will be applied to the sonar data file—how fast was the sound moving through the water?  Without this information to provide a baseline the sonar data would not be accurate.

ctd deploy 1
Randy Shingledecker gets ready to send the CTD over the side. It’s clipped into a stout line and a reel for lowering it.

ctd retrieval 1
The CTD is lowered to just above the seafloor to collect data on Conductivity, Temperature, and Depth. This data will be applied to our sonar data to obtain an accurate sound speed for this area.


 

 

 

ROCKING AND ROLLING…

When you’re out on the ocean in a boat, the most obvious variable is the instability of the surface, itself.  This is called ‘attitude’.  Attitude includes changes to the boat’s orientation fore and aft (pitch), side-to-side (roll), and up and down (heave) as it is gently, and not-so-gently rocked by ocean swells and waves.  This means that the sonar is not always where you think it is in relation to the seafloor.  This is like trying to accurately measure the height of something while you, the measurer, are on a surface that is constantly moving in 3 different directions. Good luck.  Luckily for this crew of hydrographers, each boat is equipped with a little yellow box whose technical name is the IMU (inertial measurement unit) that I call the heave-o-meter, as we bob up and down on this might ocean.  This little box contains 3 gyroscopic sensors that record all those forward and backward pitches, sideways rolls, as well as the bobbing up and down motions that the boat does while the sonar is pinging away.  This information is recorded in the launch’s computer system and is applied to the sonar data during analysis back at the Rainier.

This yellow box is the IMU.  It's internal gyros capture information about the boat's pitch, roll, and heave.
This yellow box is the IMU. It’s internal gyros capture information about the boat’s pitch, roll, and heave.

TIME AND TIDE…

Now that you’ve gotten your launch to the correct polygon (using GPS data to pinpoint your location), taken CTD readings to create a sound transmission profile for your transect area, and started up the heave-o-meter to account for rocking and rolling on the high seas, it’s time to start collecting data.  Wait—there’s still another variable to think about, one that changes twice daily and affects the height of the water column.  You also have to factor in changes in the depth of the water due to tidal changes. (for an in-depth look at how tides work, check out this link: http://oceanservice.noaa.gov/education/kits/tides/tides01_intro.html).  At high tide, there’s a greater likelihood that subsurface obstacles will be covered sufficiently.  At low tide, however, it’s pretty important to know where the shallow spots and rocks might lurk.  NOAA’s hydrographers are charting ocean depths referenced to mean lower low water, so that mariners can avoid those low-water dangers.

You might be asking yourself, who keeps track of all that tide data and, not only that, how do we know what the tide highs and lows will be in an area where there are no other tide gauges?   NOAA has tide gauges along many coastal areas.  You can go online to http://tidesandcurrents.noaa.gov/and find out predicted tide heights and times for any of these locations.  While we are working here in Cold Bay, we are using a tide gauge in nearby King Cove, as well as a tide gauge that the Rainier’s crew installed earlier this summer.  More data is better.

Here's the tide chart from the King Cove tide gauge.
Here’s the tide chart from the King Cove tide gauge.

What do you do if you’re surveying in an area that doesn’t have existing tide gauges?  In that case, you have to make your own gauge that is referenced to a non-moving point of known elevation (like a rock).  For a detailed description of how these gauges are set, check out NOAA TAS blogs from some of the teachers who preceded me on the Rainier. On Wednesday, I helped dismantle a tide gauge on Bird Island in the Shumagin Islands that had been set up earlier this season (check out TAS Avery Martin’s July 12th posting), but had ceased to report reliable data.  Our mission on Wednesday was to find out if the station had merely stopped reporting data or if it had stopped collecting data entirely. 

Setting off in a skiff to check on the Bird Island tide gauge.
Setting off in a skiff to check on the Bird Island tide gauge.

When we arrived at Bird Island we found out exactly why the gauge had stopped sending data—its battery bank had fallen from one rocky ledge to another, ripping apart the connections and breaking one of the plastic battery boxes in the process.  That took a lot of force—perhaps a wave or some crazy gust of wind tore the 3 batteries from their mooring.  Since each battery weighs over 25lbs, that means that something moved over 75lbs of batteries.  Ideally, the station uses solar panels to keep the batteries charged.  The batteries power up the station so that data can be sent to a satellite. Data is also stored on site in a data logger, but without power that data logger won’t work.

This is the data logger for the tide gauge.  It is housed in a watertight box and was retrieved for downloading on the ship.
This is the data logger for the tide gauge. It is housed in a watertight box and was retrieved for downloading on the ship.

We retrieved all the equipment and will be able to download whatever data had been recorded before the system broke. The automated tide gauge is, basically, a narrow diameter air-filled tube that is underwater and set at a fixed depth with a narrow opening pointed downward to the seafloor. The pressure required to balance the air in the tube is equal to the pressure of the water column directly above the opening.  The tide gauge measures this pressure and converts it to depth.  Pressure/depth changes are recorded every six minutes—or ten times each hour. As it turns out, the damaged battery bank was only one of the problems with this station.  Problem number two was discovered by the dive team that retrieved the underwater portion of the gauge; the hose had been severed in two locations. In this case, something had caused the tube to break, so it was no longer connected to the data logger.  That must have been some storm!

ENC Carrier inspects the battery bank that inow s on a rock ledge 2 feet below where it had been placed!
ENS Carrier inspects the battery bank that rests on a rock ledge 2 feet below where it had been placed weeks ago!

The waterproof battery boxes were broken in the tumble.
The waterproof battery boxes were broken in the tumble.

The solar panels that charged the batteries were intact, still tied into bolts in the rocks.
The solar panels that charged the batteries were intact, still tied into bolts in the rocks.

The dive crew gets ready to jump in
The dive crew gets ready to jump in

Brrr, it's chilly work diving in arctic waters.  The divers are investigating the gauge and removing the damaged hose
Brrr, it’s chilly work diving in arctic waters. The divers are investigating the gauge and removing the damaged hose

While there, we set to work checking on benchmarks that had been set earlier in the season.  We used a transit and survey rods (oversized rulers) to measure the relative heights of a series of benchmarks to ensure accuracy. There are 5 benchmarks along the beach.  Each one was surveyed as a reference to the primary benchmark nearest the gauging station.  Multiple measurements help ensure greater accuracy.

I am holding the survey rod on top of a benchmark.
I am holding the survey rod on top of a benchmark.

 

I used a level to make sure the rod was plumb--perpendicular to the benchmark.  No easy feat with a strong wind blowing!
I used a level to make sure the rod was plumb–perpendicular to the benchmark. No easy feat with a strong wind blowing!

We also were tasked with checking the primary benchmark’s horizontal location.  While this had been carefully measured when it was set back in July, it’s important to make sure that it hasn’t moved.  It might seem a crazy concept to think that a benchmark cemented into a seemingly immovable piece of rock could move, but we are in a region that experiences seismic events on an almost daily basis.  (You can check out seismic activity at http://www.aeic.alaska.edu/) NOAA Corps Officer ENS Bill Carrier set up a GPS station at the benchmark to collect 4 hour’s data on its position, a process called HORCON (horizontal control).  Unfortunately, the winds were in charge of how much data we were able to collect that day, and blew down the station after only 3 hours! [image of station down]  Sometimes the best laid plans …..

A gust of wind blew the recording station down.
A gust of wind blew the recording station down.

 

DATA, DATA, and MORE DATA

While data collection is important, it’s what you do with the data that really gets complicated.  Data management is essential when working with so many files and so many variables. Before each launch returns to the Rainier, the day’s data is saved onto a portable hard drive.  Immediately after being hauled back up onto the ship, the data is handed off to the ‘Night Processing Team’ and hustled off to the Plotting Room (computer HQ) to be uploaded into a computer.  This is where the magic happens and an advanced degree in computer science or GIS (geographic information systems) can come in handy.  I have neither of those qualifications, but I know how to read a screen, click a mouse, and follow directions.  So, on Friday evening I was ushered into the ranks of ‘night processor’.

When each launch returns to the ship, their day's data is saved onto a hard drive.  This drive is transported to the plotting room to download onto the computer.
When each launch returns to the ship, their day’s data is saved onto a hard drive. This drive is transported to the plotting room to download onto the computer.

First, data is downloaded into the main computer.  Each launch’s files are called raw data files and are recorded in the launch’s acquisition logs.  Once the data is on the computer, it is important to set up what I call a ‘file tree’; the series of files that increase in specificity.  This is analogous to having an accurate list of what files live within each drawer and section of your file cabinet. These files are color-coded according to the operations manual protocols to minimize the chance of misfiling or the data.  They are definitely more organized than the files on my laptop—I might change my lackadaisical filing ways after this trip!

Once the data are placed in their folders, the fun begins.  Remember, you have files for multiple variables;  sonar, CTD casts, the IMU Heave-o-meter, and tide data.  Not only that, you have, with any luck, performed multiple casts of your CTD meter to obtain accurate data about the conditions affecting sound wave transmission within your polygon.  Now you get to do something I have never done before (and use a vocabulary word I never knew existed and one that I might try to spell in a future Scrabble game); you concatenate your CTD data.  Basically, you put the data from all your CTD casts together into one, neat little file.  Luckily, the computer program that is used does this for you.  Next, you direct the program to add all the variables to your sonar files; the concatenated CTD data, tide data, and IMU data.

 

Survey Tech Brandy Geiger and ENS Wall begin to upload the data and organize it into files.
Survey Tech Brandy Geiger and NOAA Corpsman ENS Wall begin to upload the data and organize it into files.

Assuming all goes well and you have merged all your files, it’s time to ‘clean’ your data and review it to make sure there are no obvious holes or holidays in the data that was collected.  Holidays can occur if the launch was bouncing too much from side to side during data collection and show up as a blank spot in the data because the sonar was out of the water and not pinging off the bottom.  You can identify these holidays during the data collection process [holiday signature], but sometimes there are smaller holidays that show up once the data is merged and on your computer screen.  There can also be miscellaneous errant pings caused by debris in the water column.  Cleaning involves systematically searching each line of your surveyed polygon to identify and delete those ‘bad’ pings.  Kind of like photoshopping away the parts of a digital image that you don’t want in the final image.  You work methodically in a grid pattern from left to right and top to bottom to ensure that you are covering the whole file.  It sounds easy, but to a non-PC person such as myself all that right click, left click, center click stuff was a bit boggling.  The program is amazingly complex and, rumor has it, a little bit ‘buggy’ at times.

Multiple screens, multiple tasks.  I am learning the art of 'cleaning' the data--getting rid of extraneous pings.
Multiple screens, multiple tasks. I am learning the art of ‘cleaning’ the data–getting rid of extraneous pings.


After all this, guess what?!  You still don’t have a chart.  It takes almost 2 years to go from data collection to chart publication.  There’s endless amounts of data compilation, reports to be written, and quality control analysis to be completed before the final report and charts are issued.

Personal Log

So far I have spent two nights on the ship ‘in transit’, moving between ports. The other nights have been spent anchored offshore. While the first night at sea was a little bouncy, the second was, in my opinion, the wildest roller coaster ride I have ever taken.  Imagine being pulled to the top of a high roller coaster, and released to fly down to the bottom while you are lying flat in your bed.  That’s what it felt like as we motored from the Shumagin Islands to an anchorage in Cold Bay.  An endless series of up, up, ups, followed by a wild ride down, down, down. Luckily all the drawers and doors have latches that keep them from flying open—although I had a jacket hanging on a hook that seemed to hit the latch on one closet door and actually knock it open—after this happened a couple of times I gave up and put the coat on the floor and firmly shut the door.  My bathroom trash can ended up in the shower stall.  At one point I heard a loud thump in the dark—and realized my survival suit in its orange bag had fallen from the top bunk to the floor—glad I wasn’t in its way! It was time to just hang on and try not to roll out of bed.

If your chair isn't tied down, put tennis balls over the wheels to keep it from rolling!
If your chair isn’t tied down, put tennis balls over the wheels to keep it from rolling!

tiedown1
Strap the printer tightly to a table!

tiedown2
Don’t forget to secure the trashcans!

We finally stopped rocking and rolling around 3 in the morning.  I thought maybe I was just a bit sensitive to the rocking motion, but was comforted to find out the everyone agreed that it had been a wild night.  In fact, one of the potential ‘hazards’ for our work on Thursday was ‘lack of sleep’.

FOO Meghan Mcgovern goes over the Plan of the Day (POD).  Today's identified hazards included 'Lack of Sleep'.
FOO LT Meghan McGovern goes over the Plan of the Day (POD). Today’s identified hazards included ‘Lack of Sleep’.

 

After almost a week aboard the Rainier I have been impressed with the teamwork, precision, and overall efficiency which overlays all operations. This crew can get a launch loaded, lowered, and underway in less time than it sometimes takes me to record my morning attendance at school!  This is no simple feat (the boat, not the attendance!).  It reminds me of a buzzing beehive filled with activity and focused on a single task; data collection. Each day begins on the fantail (the rear of the boat) at 0800 with the FOO (Field Operations Officer) reviewing the POD (Plan of the Day) and a summary of the day’s goals, work assignments, weather, and potential hazards, prior to sending out the survey crews.

The Boatswain (bo’sun) directs the next part of this tightly choreographed activity, as the launches are lowered by their davits (small cranes), while lines and hooks are handled with an eye to safety and efficiency.  Within 5 minutes the two launches have been lowered, loaded with crew and supplies, and are on the water, buzzing away from the hive like bees to perform their daily waggle dance as they move back and forth collecting hydrographic data.

At 1630 they return to the hive, filled with the sweet nectar of hydrographic data.  Launches are lifted back onto the ship and the data is whisked off to the computer room for downloading. 5 Minutes later a survey team debrief is held to review work accomplished that day and any problems that may have come up so that plans can be made for the next day’s work.  This crew is organized!!

The NOAA Ship Rainier
The NOAA Ship Rainier

 

 

 

Katie Sard: A Brief History, and the “Simple” Science of Sonar, August 9, 2013

NOAA Teacher at Sea
Katie Sard
Aboard NOAA Ship Rainier
July 29-August 15, 2013

Mission:  Hydrographic Survey
Geographical Area of the Cruise:  Shumagin Islands, AK
Date:  August 5-8, 2013

Weather Data from the Bridge:
GPS location:  54°49.402’N, 159°33.182’W
Sky condition: Overcast (OVC)
Visibility: 5 nm
Wind: 210 true, 15 kts
Water temperature: 8.3°C
Air temperature: 11.0°C

The NOAA Ship Rainier.  This has been my home for the past 12 days!
The NOAA Ship Rainier. This has been my home for the past 12 days!

Science and Technology Log

While I was speaking with ENS Rosemary Abbitt, a Junior Officer on board, she used an analogy to describe the amount of information that she takes in every day while on the job.  She said that it is like trying to get a drink from a fire hose.  I thought that this was fitting as each day as a Teacher at Sea I am constantly trying to take in and process the huge amount of new information I am learning.  I have jumped in to the heart of hydrographic surveys, but in this post I would like to take a step back and look at a brief history of how the use of sonar has evolved.

Before coming on the Rainier, I knew that the use of sonar on ships had something to do with sound waves traveling in the water in order to map the ocean floor.  After gathering information from the crew, and a bit of my own research, I found out that sonar actually stands for Sound Navigation and Ranging.  I also found out that sound waves travel better in water as compared to radar or light waves, so that is why they are used for this type of work.

The top-side unit of the sonar system that is used on board.  This machine acts as the "brain" of the sonar system.
The top-side unit of the sonar system that is used on board. This machine acts as the “brain” of the sonar system.

The NOAA Ship Rainier is equipped with a Kongsberg EM710 Multibeam Sonar System which falls in the category of active sonar.  The system emits acoustic signals into the water, and when the sound bounces off of an object it returns an echo to the sonar transducer.  By determining the time between emission and reception, the range and the orientation of the object can be determined.  The range of an object is equal to the sound speed times the travel time divided by two.

On the left you can see the machine that is used to drag the MVP in the water behind the ship while we are surveying.  On the right, the MVP is ready to go in the water.
On the left you can see the machine that is used to drag the MVP in the water behind the ship while we are surveying. On the right, the MVP is ready to go in the water.

It is extremely important that the hydrographers using this technology have accurate measurements for sound speed.  The Rainier is equipped with a Moving Vessel Profiler (MVP) which generates sound speed profiles.  These profiles include information such as temperature, salinity, depth, and most importantly, sound speed.  These measurements are applied to real-time sonar data in order to make sure that these variables are controlled for.

Sonar was first used during World War I as a way of detecting submarines.  The US Coast and Geodetic Survey were the first to use sonar to map deep water areas in the 1920s.  As I discussed in a previous post, lead line surveys were the primary way to gather bathymetric data up until that point.  It astounds me to see all of the technology on board, but it also leaves me wondering where we’ll be in another 10 to 20 years.  I suppose only time will tell what new technologies will allow for the continued exploration of our Ocean!

Personal Log

The beauty of Alaska has truly come to life for me in the last few days.  Last night, the CO was kind enough to take a group of people to a nearby beach on Chernabura Island.  From time to time he will do this, and the crew calls these events “Beach Parties”.  It took me several minutes to gain my land legs as my body has acclimated to life on a ship.  I walked the beach, but I soon turned to hike up one of the peaks that I had been seeing from a distance for so many days.

My footsteps on the beach at Chernabura Island.  It's crazy to think how few people have walked on this land.
My footsteps on the beach at Chernabura Island. It’s crazy to think how few people have walked on this land.

The hike up to the top was HARD!  The ground beneath my feet was not solid earth, but rather soft, boggy terrain that required a great deal of energy to hike through.

The view from a stop along the way. Looking out over Chernabura Island.
The view from a stop along the way. Looking out over Chernabura Island.

When I made it to the top I could not believe my eyes.  The beauty of this untouched land was overwhelming, and I realized how very lucky I am to be on this wonderful adventure.

A hidden lake in the background at the top of the ridge on Chernabura Island.
A hidden lake in the background at the top of the ridge on Chernabura Island.

The ship in the distance from the top of the ridge on Chernabura Island.
The ship in the distance from the top of the ridge on Chernabura Island.

Just another Day at the Office…

Christie Reiser, Hydrographic Assistant Survey Technician

Christie Reiser
Christie Reiser

I began getting to know Christie while I was out on my first launch with her last week.  Before this time, I had heard her mentioning that she is currently doing an internship with NOAA.  This immediately caught my attention as I am always interested in how students are able to involve themselves with real-world organizations such as NOAA.  As I began interviewing her I found out that she is working on her bachelor’s degree through the University of Colorado with hopes of someday becoming a physical scientist.  She began her internship with NOAA last field season, and she is now a permanent employee while also completing her internship.  Before her current school work she obtained an associates degree in business marketing and worked for an oil company as an executive assistant.  During that time, her boss asked if she wanted to learn Geographic Information Systems (GIS) for her work, and so she was signed up for a crash course which allowed her to begin using the software to make maps.  Unfortunately, she was laid off but during this time she was able to move to Europe because she has dual nationality in Germany. While overseas, she spent a year working as an apprentice in a saddlery in Austria.  When she came back to the states, she decided to go back to school at the University of Colorado.  She enjoyed her previous GIS experience, so she began her work in the geography department which led her to the internship with NOAA.

Christie told me that has truly enjoyed her time in Alaska.  She loves seeing the marine life and getting to know the people she works with so well.  Her favorite part of the work is the night processing where she is able to work directly with the data in order to see the sea floor come to life.  When asked what advice she would give a young person trying to break into this field, she said that she would recommend waiting to go to college until you are ready.  Wait to find something that makes you happy and that you have a passion for.

When not on the ship, Christie enjoys leather working, saddle making, and book binding.

Your Questions Answered!

One question that I’ve had from several people has to do with the morale of the crew.  These people are out to sea for 18 days at a time, and so people wanted to know if it gets depressing out here.  Also, it was asked if there is  good comradery and banter among the crew?

In response, I can say this; life at sea is not for the shy or the meek.  While there are many amazing advantages to this type of work it definitely takes a certain type of person.  As far as the morale of the crew, from my perspective it seems like field season up here means time to get business done.  Everyone has important tasks to be completed, and most of the time people are busy with work.  Operations run 24 hours, and the point of being here is to gather the data. However, it’s not all work and no play.  Morale on the ship is important, and I’ve heard many people speak of the crew as a second or extended family.  I don’t know any other job where you work, live, and share space 24 hours a day with the same people.  I’ve noticed that people on the ship really look forward to meals.  It is one of the small pleasures of life at sea and it is a time to gather with everyone and take a break.  The universal struggle on board is the time away from home. Nobody wants to be away from their loved ones, but the crew on the Rainier work as hard as possible to make life at sea enjoyable.

My Aunt Kathy wanted to know if I have seen any whales.  The ship has had to navigate around pods of whales, but it seems to be whenever I am busy with something else.  Yesterday the crew called me to the bridge as they had been seeing a lot of whale activity.  Of course, as soon as I got my camera out, there wasn’t a whale in sight.  However, last night I was walking on Chernabura Island during the beach party, and I saw a pod of whales out in the distance.  I saw four of five spouts, but they were too far to get a picture.

The first sunset I've seen since being on board.
The first sunset I’ve seen since being on board.

Did You Know…

Here are a few ship specific terms that I have learned during my time aboard the Rainier:

To come about – to turn the ship around

Aft – the back of the ship

Helm – ship’s steering equipment, found on the bridge

Pitch – the forward and backward rise and fall of the ship as it moves

Leeward – the side of an island or a ship that is sheltered from the wind

Also, when making a call to another vessel, it is important to say the call sign of the vessel you are calling for first followed by your own call sign.  When I was out on RA-6 doing survey launches, I had to call the Rainier to give hourly updates.  In a previous blog I told you that the call sign for the Rainier is WTEF, but they typically shorten it when out on surveys to just ET.  In this case when I was calling for the ship I would say, “Echo Foxtrot this is RA-6.”  The OOD would respond with, “RA-6 this is Echo Foxtrot go ahead.”  This type of universal communication system is one of the ways that the team aboard the Rainier maintains safety while at sea.

Julia Harvey: Calibration in Sea-Otterless Sea Otter Bay, August 7, 2013

NOAA Teacher at Sea
Julia Harvey
Aboard NOAA Ship Oscar Dyson (NOAA Ship Tracker)
July 22 – August 10, 2013 

Mission:  Walleye Pollock Survey
Geographical Area of Cruise:  Gulf of Alaska
Date: 8/7/13 

Weather Data from the Bridge (as of 21:00 Alaska Time):
Wind Speed:  10.42 knots
Temperature:  13.6 C
Humidity:  83%
Barometric Pressure:  1012.4 mb

Current Weather: A high pressure system is building in the east and the swells will increase to 8 ft tonight.

Science and Technology Log:

Before I begin, I must thank Paul for educating me on the calibration process.  Because calibration occurred during the day shift, I was not awake for some of it.

The EK60 is a critical instrument for the pollock survey.  The calculations from the acoustic backscatter are what determines when and where the scientists will fish.  Also these measurements of backscatter are what are used, along with the estimates of size and species composition from the trawling, to estimate fish biomass in this survey.  If the instruments are not calibrated then the data collected would possibly be unreliable.

Calibration of the transducers is done twice during the summer survey.  It was done before leg one in June, which began out of Dutch Harbor, and again now near Yakutat as we end leg three and wrap up the 2013 survey.

As we entered Monti Bay last night, Paul observed lots of fish in the echosounder.  This could pose a problem during calibrations.  The backscatter from the fish would interfere with the returns from the spheres.  Fortunately fish tend to migrate lower in the water column during the day when calibrations were scheduled.

This morning the Oscar Dyson moved from Monti Bay, where we stopped last night, into Sea Otter Bay and anchored up.  The boat needs to be as still as possible for the calibrations to be successful.

Monti and Sea Otter Bays Map by GoogleEarth
Monti and Sea Otter Bays
Map by GoogleEarth

Site of calibration: Sea Otter Bay
Site of calibration: Sea Otter Bay

Calibration involves using small metal spheres made either of copper or tungsten carbide.

Chief Scientist Patrick Ressler with a tungsten carbide sphere
Chief Scientist Patrick Ressler with a tungsten carbide sphere

Copper sphere photo courtesy Richard Chewning (TAS)
Copper sphere
photo courtesy Richard Chewning (TAS)

The spheres are placed in the water under transducers.  The sphere is attached to the boat in three places so that the sphere can be adjusted for depth and location.  The sphere is moved throughout the beam area and pings are reflected.  This backscatter (return) is recorded.  The scientists know what the strength of the echo should be for this known metal.  If there is a significant difference, then data will need to be processed for this difference.

The 38 khz transducer is the important one for identifying pollock.  A tungsten carbide sphere was used for its calibration. Below shows the backscatter during calibration, an excellent backscatter plot.

Backscatter from calibration
Backscatter from calibration

The return for this sphere was expected to be -42.2 decibels at the temperature, salinity and depth of the calibration  The actual return was -42.6 decibels.  This was good news for the scientists.  This difference was deemed to be insignificant.

Personal Log:

Calibration took all of the day and we finally departed at 4:30 pm.  The views were breathtaking.  My camera doesn’t do it justice.  Paul and Darin got some truly magnificent shots.

Goodbye Yakutat Bay
Goodbye Yakutat Bay

As we left Yakutat Bay, I finally saw a handful of sea otters.  They were never close enough for a good shot.  They would also dive when we would get close.  As we were leaving, we were able to approach Hubbard Glacier, another breathtaking sight.  Despite the chill in the air, we stayed on top getting picture after picture.  I think hundreds of photos were snapped this evening.

The Oscar Dyson near Hubbard Glacier
The Oscar Dyson near Hubbard Glacier

Location of Hubbard Glacier.  Map from brentonwhite.com
Location of Hubbard Glacier. Map from brentonwhite.com

Many came out in the cool air to check out Hubbard Glacier
Many came out in the cool air to check out Hubbard Glacier

I even saw ice bergs floating by
I even saw ice bergs floating by

Lots of ice from the glacier as we neared
Lots of ice from the glacier as we neared

Nearby Hubbard Glacier with no snow or ice
Near Hubbard Glacier

And there it is: Hubbard Glacier
And there it is: Hubbard Glacier

Hubbard Glacier
Hubbard Glacier

Hubbard Glacier
Hubbard Glacier

Did You Know?

According to the National Park Service, Hubbard Glacier is the largest tidewater glacier in North America.  At the terminal face it is 600 feet tall.  This terminal face that we saw was about 450 years old.  Amazing!

Read More about Hubbard Glacier

Rosalind Echols: Sound Off! From Noise to Nautical Charts, July 22, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier (NOAA Ship Tracker)
July 8 — 25, 2013 

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 22, 2013

Current Location: 54° 55.6’ N, 160° 10.2’ W

Weather on board: Broken skies with a visibility of 14 nautical miles, variable wind at 22 knots, Air temperature: 14.65°C, Sea temperature: 6.7°C, 2 foot swell, sea level pressure: 1022.72 mb

Science and Technology log:

Teamwork, safety first
Rainier motto, painted in the stern of the ship above the fantail, the rear lower outside deck where we have our safety meetings.

“Teamwork, Safety First”, is inscribed boldly on the Rainier stern rafter and after being aboard for more than 2 weeks, it is evident this motto is the first priority of the crew and the complex survey operation at hand.

Rainier launch
This is one of the survey launches that we use to gather our survey data. In this case, the launch is shown approaching the Rainier, getting ready to tie up.

It’s a rainy overcast morning here in SW Alaska and we are circled around the officers on the fantail for the daily safety meeting. Weather conditions, possible hazards, and the daily assignment for each launch are discussed. Per the instructions on the POD (Plan of the Day), handed out the previous evening, the crew then disperse to their assigned launches. The launches are then one-at-a-time lowered into the water by the fancy davit machinery and driven away by the coxswain to their specific “polygon” or survey area for the day. A polygon surveyed by a launch on average takes 2-3 hours at 6-8 knots to survey and usually is an area that is inaccessible by the ship. Many polygons make up one large area called a “sheet” which is under the direction of the “sheet manager”. Several sheets make up an entire survey project. Our hydrographic project in the Shumagins has 8 sheets and makes up a total of 314 square nautical miles.

Safety meeting
The CO, XO, and FOO lead the safety meeting for the day, discussing weather conditions, water conditions, and the assignments for each launch.

Shumagin Islands
This is a chart of the Shumagin Islands showing the 8 sheets (highlighted in green) that we are surveying.

Polygons
East side of Chernabura Island divided into survey “polygons”, each labeled with a letter or word. Notice how each polygon is a small subset of the larger sheet.

On board each launch we have a complex suite of computer systems: one manages the sonar, another manages the acquisition software, and the third records the inertial motion of the launch as it rocks around on the water (pitch, heave, roll). The acquisition system superimposes an image of the path of the launch and the swath of the sonar beam on top of a navigational chart within the polygon. Starting at one edge of the polygon, the coxswain drives in a straight a line (in a direction determined by the sheet manager), to the other end of the polygon, making sure there is some overlap at the boundaries of the swaths. He/she then works back in the other direction, once again making sure there is some overlap with the adjacent swath. We call this “mowing the lawn,” or “painting the floor” as these are visually analogous activities. Throughout the day, we pause to take CTD casts so that we have a sound velocity profile in each area that we are working.

Launches
Typical launch dispersal for a survey day. Launches are signified by “RA-number”. You can also see the location of our tide measurement station and GPS control station, both of which we use to correct our data for errors.

Mowing the lawn
This image shows the software tracking the path and swath of the launch (red boat shape) as it gathers data, driving back and forth in the polygon, or “mowing the lawn.” The darker blue shaded area shows overlap between the two swaths. The launch is approaching a “holiday”, or gap in the data, in an effort to fill it in.

You might be wondering, why the swath overlap? This is to correct for the outer sonar beams of the swath, which can scatter because of the increased distance between the sea floor and the sonar receiver below the hull of the boat. The swath overlap is just one of the many quality control checks built into the launch surveying process. Depending on the “ping rate”, or the number of signals we are able to send to the bottom each second, the speed of the boat can be adjusted.  The frequency of the sound wave can also be changed in accordance with the depth. Lower frequencies (200 khz) are used for deeper areas and higher frequencies (400 khz) are used for shallower areas.

Rosalind in launch
Rosalind in front of the computers on the launch, checking for sonar quality (right screen) and observing the path of the ship, to make sure there are no gaps in the data, or “holidays”.

Despite what might seem like mundane tasks, a day on board the launch is exhausting, given the extreme attention to detail by all crew members, troubleshooting various equipment malfunctions, and the often harsh weather conditions (i.e. fog, swells, cool temperatures) that are typical of southwest Alaska. The success of the ship’s mission depends on excellent communication and teamwork between the surveyors and the coxswain, who work closely together to maximize quality and efficiency of data collection. Rain or shine, work must get done.  But it doesn’t end there. When the launches arrive back at the ship, (usually around 4:30 pm), the crew will have a debrief of the day’s work with the FOO (field operations officer) and XO (executive officer). After dinner, the survey techs plunge head first (with a safety helmet of course) into the biggest mountain of data I have EVER witnessed in my life, otherwise known as “night processing”. We are talking gigabytes of data from each launch just for a days work.  It begins with the transferring of launch data from a portable hard drive to the computers in the plot room. This data is meticulously organized into various folders and files, all which adhere to a specific naming format. Once the transferring of data has finished, the “correction” process begins. That’s right, the data is not yet perfect and that’s because like any good science experiment, we must control for extraneous factors that could skew the depth data. These factors include tides, GPS location error, motion of the launch itself, and the sound velocity in the water column.

Plot room
Our chief surveyor works in the plot room cleaning and correcting data.

Data cleaning.
Data showing the consequences of the tide changing. The orange disjointed surface shows the data before it was adjusted for the tide changing. You can see how the edges between swaths (i.e. red and olive green) do not match up, even though they should be the same depth.

Sound speed artifact
This image shows the edge effects of changing sound speed in the water column. The edges of each swath “frown” because of refraction owing to changing density in the water column. This effect goes away once we factor in our CTD data and the sound speed profile.

In previous posts, I discussed how we correct for tides and the sound velocity. We also correct for the GPS location of the launch during a survey day, so that any specific data point is as precisely located as possible. Although GPS is fairly accurate, usually to within a few meters, we can get even more precise by accounting for small satellite errors throughout the day. The Coast Guard provided Differential GPS allows us to position ourselves to within a meter. To get even more precise, within a few centimeters, we determination location of a nearby object (our Horizontal Control, HorCon, Station) very precisely, and then track the reported position of this object throughout the day. Any error that is recorded for this station is likely also relevant for our launch locations, so we use this as the corrector. For example, if on July 21, 2013, at 3pm, the GPS location of our Bird Island HorCon station was reported 3cm north of its actual location, then our launches are also probably getting GPS locations 3cm too far north, so we will adjust all of our data accordingly. This is one of the many times we are thankful for our software. We also account for pitch, heave, and roll of the launch using the data from the inertial motion unit. That way, if the launch rolled sideways, and the center beam records a depth of 30 meters, we know to adjust this for the sideways tilt of the launch.

HorCon station
This shows the set up of our Horizontal Control and tide gauge station. The elevated rock position was chosen to maximize satellite visibility.

After all correctors have been applied (and a few software crashes weathered), the survey technicians then sort through all the data and clean out any “noise.” This noise represents sound reflections on sea life, air bubbles, or other items that are not part of the seafloor. Refraction of sound waves, as mentioned in the last post, is caused by density changes in the water due to changes in the temperature, pressure, or salinity.

Dirty data
This shows sonar data with “noise”. The noise is the seemingly random dots above and below the primary surface. On the surface itself, you can see data from four different swaths, each in a different color. Notice the overlap between swaths and how well it appears to be matching up.

Cleaned surface
This shows sonar data after the “noise” has been cleaned out. Notice how all data now appears to match a sea floor contour.

Many of the above correctors are applied the same day the data is collected, so the sheet manager can have an up-to-date record of the project’s progress before doing final planning for data collection the next day. After a sheet has been fully surveyed and ALL correctors applied, the sheet manager will complete a “descriptive report”, which accompanies the data and explains any gaps in the sonar data (“holidays”) and/or other errors present. This report, along with the data, is sent to the Pacific Hydrographic Branch for post-processing and Quality Control. After that the data is forwarded to the Marine Charting Division where the data undergoes a final set of Quality Assurance checks and is put in a format that can be printed on a paper nautical chart. From acquisition on the launches to publication on a chart, the process can take up to two years! The length of the process is designed to ensure maximum accuracy as many mariners rely on accurate charts for safe navigation.

Personal Log

As the saying goes, “When in Rome, do as the Romans.” One of the attractions of life in Alaska is access to excellent fishing, and a wide variety of tasty fish species. Although I normally consider myself to be a fairly outdoorsy person, thus far in my life this had not extended to the activity of fishing. However, inspired by Avery’s enthusiasm, and her first successful halibut catch, I decided at least give it a try, obtaining an Alaska fishing license and preparing myself for yet another adventure. I am, after all, always encouraging other people to try new things, especially things that make them a bit nervous, so it only felt right to follow some of my own advice. Honestly speaking, though, the thought of catching the fish and then having to deal with the consequences made me a little anxious.

Rosalind with fish
Rosalind with her first ever fish catch, trying very hard to keep her fingers away from the tip of the hook and the very spiny and painful back fin of the fish. Black rock fish have venomous points on their fins.

Fortunately, I had excellent guidance in this activity, setting out with Avery and two very patient crew members, who put up with my initial lack of skill and muscle, and intense enthusiasm about even the smallest jellyfish in the water. I had realized after my shoreline rock verification expedition that pointing at everything in the water and shouting “Look!” was probably not that helpful if we were trying to identify rocks, but here it seemed more appropriate. At least if you think jellyfish are cool. After several lackluster hours, we finally found a spot where a group of Black Rock Fish were schooling, and caught quite a few very quickly. Not surprisingly, the fish aren’t that happy about being caught and flail around a fair amount. Considering that they have pointy, venomous spines in their dorsal fin, it takes great care to get the fish in the bucket without injury, but we successfully managed it.

Rosalind cleaning
Rosalind learning how to fillet a black rock fish. Notice the safe distance between knife and fingers!

Somehow, in all my years of school, I never actually dissected anything, and have always felt a little squeamish around dead animals. However, after helping catch the fish, I couldn’t very well leave my colleagues alone to deal with the arduous task of filleting and cleaning the fish, so I decided to do my best to participate. It actually went much better than I expected, and I learned quite a bit about fish anatomy along the way. For example, fish have an air bladder that allows them to float. They look much less impressively large when this is deflated.

Fish fillets
A sampling of our collection of black rock fish fillets, mid-way through cleaning. I am proud to have contributed to this!

All in all, it was a very satisfying experience. It is nice to be able to say that I have developed a somewhat useful life skill (fishing as well as avoiding my fingers with large knives). Our wonderful cook, Kathy, even used some of the fish for a delicious lunch of fish tacos, which I hope to try to replicate myself some time in the near future.

FIsh tacos
Delicious fish tacos made from Black Rock Fish caught by Rainier crew and Teachers at Sea Rosalind and Avery!

Fun Fact: a fathom, a maritime measurement for depth equal to six feet, was originally based on the distance between a man’s outstretched finger tips. The word itself derives from an Old English word meaning outstretched or embracing arms. Given that we use it to measure depth, it is also interesting to note that it is related to the word to fathom something, or the adjective unfathomable, meaning immeasurable. The word is also related to the phrases “six feet under” and to “deep six” something.

Avery Marvin: Beaming With Excitement – Sound Waves and the Sea Floor, July 19, 2013

NOAA Teacher at Sea
Avery Marvin
Aboard NOAA Ship Rainier (Ship Tracker)
July 8-25, 2013 

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 19, 2013

Current Location: 54° 49.684 N, 159° 46.604 W

Weather Data from the Bridge: Foggy and overcast, wind 21 knots, air temperature: 11.5° C

Science and Technology Log:

As the fog horn sounds every two minutes and we sail solitary through the ocean, we are now in full swing surveying the Shumagin Islands, between and around Nagai, Bird, and Chernabura Islands. Unlike the old-time surveyors who used lead lines (lead weight attached to a long string), we are using a multibeam sonar system, which enables us to gather a large quantity of very accurate data in a more efficient and timely fashion.

3D sea floor
Processed sonar data showing 3D image of the sea floor.

Sonar, (SOund Navigation And Ranging) uses the principle of sound wave reflection to detect objects in the water. Just as our eyes see the reflection of visible light off of the objects around us to create a visual image, when a sound wave hits something, it reflects off that “thing” and returns to its starting point (the receiver). We can measure the time it takes for a pulse to travel from the Sonar device below the boat to the ocean floor and then back to the receiver on the boat. Using a simple distance=speed * time equation, we can get the water depth at the spot where each beam is reflected.

The skiff that we use for the shoreline activities discussed in the last post has a single-beam sonar system that directs a pulse straight down beneath the hull to get a rough depth estimate. However, for our hydrographic work on the ship and launches, we use a multibeam system that sends 512 sound pulses simultaneously towards the sea floor over a 120° angle. When many sound waves or “beams” are emitted at the same time (called a pulse) in a fan like pattern (called a swath), the reflected information creates a “sound picture” of the objects or surface within that swath range. The actual width of this swath varies with the depth, but with 512 beams per pulse, and sending out between 5-30 pulses every second, we acquire a lot of data. If you piece together many swaths worth of data you get a continuous topographical or physical map of the ocean floor, and thus the depth of the water. For more information about the specific sonar system used aboard the Rainier and its launches, check out the ship page or the NOAA page about their hydrography work.

Multibeam
Graphic showing an example of the multibeam swath below a launch. Notice how the swath gets wider as the depth increases.

Multibeam data
Cross section of sea floor data showing dot or “ping” for each multibeam measurement. Notice how many individual measurements are represented in this one section.

Swath data
Cross section of sea floor data. Each color represents data from one swath. Notice the overlap between swaths as well as the width for each one.

3D floor image
Processed sonar data showing 3D image of the sea floor.

In order to understand the complexities of sonar, it is important to understand the properties of sound. Sound is a pressure wave that travels when molecules collide with each other. We know that sound can travel in air, because we experience this every day when we talk to each other, but it can also travel in liquids and solids (which whales rely on to communicate). As a general rule, sound travels much faster in liquids and solids than in air because the molecules in liquids and solids are closer together and therefore collide more often, passing on the vibration at a faster rate. (The average speed of sound in air is about 343 meters every second, whereas the approximate speed of sound in water we have been measuring is around 1475 meters every second). Within a non-uniform liquid, like saltwater, the speed of sound varies depending on the various properties of the saltwater at the survey site. These properties include water temperature, dissolved impurities (i.e. salts, measured by salinity), and pressure. An increase in any of these properties leads to an increase in the speed of sound, and since we’re using the equation distance = speed * time equation, it is crucial to consistently measure them when seeking depth measurements.

CTD Data
Data from CTD showing temperature vs. sound speed from one data set. Notice how the temperature and sound speed seem correlated.

To measure these properties, a device called a CTD (Conductivity-Temperature-Depth) is used. Conductivity in this acronym refers to the free flowing ions in salt water (Na and Cl, for example), which are conductive and the concentration of these ions determines the salinity of the water. The CTD measures these three properties (Conductivity, Temperature and Depth) so the speed of sound in the water can be calculated at every point in the water column

To use the CTD, lovely humans like Avery and I will drop it into the water (it is attached to a winch system) at the area where we are surveying and as it travels to the sea floor, it takes a profile of the three saltwater properties mentioned before. Back in the computer lab, software takes this profile data and calculates the sound velocity or speed of sound through the water in that region.  As a crosscheck, we compare our profile data and sound velocity figures obtained at the site to historical measured limits for each property. If our measurements fall significantly outside of these historical values, we might try casting again or switch to a different CTD. However, because we are surveying in such a remote area, in some cases, data outside historical limits is acceptable.

CTD graphs
Graph of our sound speed vs. depth data showing comparison to historical data.

Given that we are trying to determine the water depth to within centimeters, variations in the sound speed profile can cause substantial enough errors that we try to take a “cast” or CTD reading in each small area that we are gathering data. The software the survey team uses is able to correct automatically for the sound velocity variations by using the data from the CTD. This means that the depth profile created by the sonar systems is adjusted based on the actual sound velocities (from the CTD data) rather than the surface sound speed. We are also able to account for speed changes that would cause refraction, or a bending of the beam as it travels, which would otherwise provide inaccurate data about the location of the sea floor.

Avery lowers the CTD into the water for a "cast". The CTD needs to sit in the water for a few minutes to acclimate before being lowered for a profile.
Avery lowers the CTD into the water for a “cast”. The CTD needs to sit in the water for a few minutes to acclimate before being lowered for a profile.

Avery successfully hauls in the CTD out of the water.
Avery successfully hauls in the CTD out of the water.

Personal Log:

You can’t go to Alaska without fishing its waters, rich with a variety of delectable fish species.  So I decided to get my Alaskan recreation fishing license and try my hand at it on the fantail (stern) of the Rainier, while we were anchored in Bird Island cove. Carl VerPlanck, an experienced fisherman with arms like Arnold Schwarzenegger, had coached me on the best jigging techniques for catching a halibut and with my eyes (and mind) on the prize I followed his instructions diligently.  It paid off as I landed several fish my first night on the fantail, with one halibut being a true keeper. John Kidd, NOAA Corps. Officer, gaffed my meaty fish over the steep rail of the Rainier and hauled it aboard.  He was impressed with my catch (and hidden fishing talent), stating “This is the biggest fish caught so far this season.” Woohoo! Most impressive was the amount of meat the fish yielded (4 large filets) which I proudly donated to the kitchen and John. (Three big filets to the kitchen and one filet to John for his camaraderie, the use of his high-tech rod set-up and filleting skills). The following night, we all ate delicious baked Pacific Halibut filets, coated in a creamy Caesar glaze, prepared by chef-extraordinaire, Kathy. It’s pretty cool that I got to feed the ship!!

Avery's meaty catch, a Pacific Halibut.
Avery’s meaty catch, a Pacific Halibut.

John Kidd (NOAA Officer) filleting my halibut
John Kidd (NOAA Corps. Officer) filleting my halibut

Look at all that meat!
Look at all that meat!

4 large fillets from the halibut
4 large fillets from the halibut

This was my first time catching a halibut and after close examination (and dissection) of this large, rather bizarre looking flatfish I became very intrigued and had several questions: How and why do the eyes migrate to one side?  How do you tell the age of a halibut? What does the word “halibut” mean?

Like any good scientist, I proceeded to find the answers to these questions, and in doing so, learned many more interesting tidbits about Halibut. (The other species of halibut is the Atlantic Halibut which is very similar to the Pacific Halibut and is named as such for the ocean it occupies.)

So lets start with the name “halibut.” It’s origin is Latin (hali=haly=holy, but=butt=flat fish) and literally translates to “holy flat fish” because it was popular on Catholic holy days. Now what’s with the eye migration and why are both eyes on the same side? Well to understand this question thoroughly we must look at the conditions under which the halibut is born. Female halibut are sexually mature at age 12, spawning from November to March in deep water (300-1500 feet). Depending on their size, females release several thousand to several million eggs which are fertilized externally by the males. After the eggs are fertilized by the males, they become buoyant and start to float up the water column, hatching into free floating larva at about 16 days.  As the larva mature, they continue to rise to the surface. At this larval stage they are upright, like any other “regular” fish, with one eye on each side of their head. This eye placement makes sense, considering they are in the open ocean with water on all sides of them.  When at or near the surface, the larvae drift towards shore by ocean currents. As they get closer to shore and at about 1 inch in length, they undergo a very unique metamorphosis in which the left eye moves over the snout to the right side of the head. At the same time their left side fades in color eventually becoming white and their right side becomes a mottled olive-brown color. By 6 months, they are ready to settle to the bottom in near shore areas, hiding under the silt and sand, with just eyes exposed. Their mottled side will be face up, blending into their surrounds and their white side will face down, creating a “countershading” coloration, which helps keep them hidden from predators.

From halibut larvae to adult halibut. Notice the migration of the left eye to the right side and the pigmentation at the last stage.
Halibut development: from halibut larvae to adult halibut. Notice the migration of the left eye to the right side and the pigmentation at the last stage.

The Pacific Halibut I caught was by no means a monster or “barn door” as the huge ones are called. But it also was not a “chicken”, slang for a small halibut. Female halibut can reach lengths of 8 feet and a weight of 500+ pounds. Males rarely exceed 100 pounds.  Halibut are generally not picky eaters and will pretty much eat anything that lives in the ocean.  Carl joked that a halibut would even eat an old shoe dangling from a fishing pole.

I was surprised to learn that halibut can live as long as 55 years.  Scientists can accurately age a halibut by counting the rings in their ear bone or “otolith”, similar to dating a tree using its annual growth rings. So next time you catch a halibut and plan on keeping it, try to find the ear bone, grab a microscope and age the fish. If that fails, don’t forget to cut the cheeks out of the halibut (along with the 4 regular meaty fillets), for I am told that is the best part to eat. 🙂

Halibut otolith or ear bone that can be used to age the fish by counting the rings under a microscope
Halibut otolith or ear bone that can be used to age the fish by counting the rings on the otolith (under a microscope).

Fun factoid: Sonar works a lot like the echo sounding of a bat, and its development was partially prompted by the Titanic disaster.

Rosalind Echols: Beaming With Excitement – Sound Waves and the Sea Floor, July 19, 2013

NOAA Teacher at Sea
Rosalind Echols
Aboard NOAA Ship Rainier (Ship Tracker)
July 8-25, 2013 

Mission: Hydrographic Survey
Geographical Area of Cruise: Shumagin Islands, Alaska
Date: July 19, 2013

Current Location: 54° 49.684 N, 159° 46.604 W

Weather Data from the Bridge: Foggy and overcast, wind 21 knots, 11.5° C

Science and Technology Log:

Foggy islands
View from the launch while gathering our multibeam sonar data.

As the fog horn sounds every two minutes and we sail solitary through the ocean, we are now in full swing surveying the Shumagin Islands, between and around Nagai, Bird, and Chernabura Islands. Unlike the old-time surveyors who used lead lines (lead weight attached to a long string), we are using a multibeam sonar system, which enables us to gather a large quantity of very accurate data in a more efficient and timely fashion.

3D sea floor
Processed sonar data showing 3D image of the sea floor.

Sonar, (SOund Navigation And Ranging) uses the principle of sound wave reflection to detect objects in the water. Just as our eyes see the reflection of visible light off of the objects around us to create a visual image, when a sound wave hits something, it reflects off that “thing” and returns to its starting point (the receiver). We can measure the time it takes for a pulse to travel from the Sonar device below the boat to the ocean floor and then back to the receiver on the boat. Using a simple distance=speed * time equation, we can get the water depth at the spot where each beam is reflected.

The skiff that we use for the shoreline activities discussed in the last post has a single-beam sonar system that directs a pulse straight down beneath the hull to get a rough depth estimate. However, for our hydrographic work on the ship and launches, we use a multibeam system that sends 512 sound pulses simultaneously towards the sea floor over a 120° angle. When many sound waves or “beams” are emitted at the same time (called a pulse) in a fan like pattern (called a swath), the reflected information creates a “sound picture” of the objects or surface within that swath range. The actual width of this swath varies with the depth, but with 512 beams per pulse, and sending out between 5-30 pulses every second, we acquire a lot of data. If you piece together many swaths worth of data you get a continuous topographical or physical map of the ocean floor, and thus the depth of the water. For more information about the specific sonar system used aboard the Rainier and its launches, check out the ship page or the NOAA page about their hydrography work.

Multibeam
Graphic showing an example of the multibeam swath below a launch. Notice how the swath gets wider as the depth increases.

Multibeam data
Cross section of sea floor data showing dot for each multibeam measurement. Notice how many individual measurements are represented in this one section.

Swath data
Cross section of sea floor data. Each color represents data from one swath. Notice the overlap between swaths as well as the width for each one.

3D floor image
Processed sonar data showing 3D image of the sea floor.

In order to understand the complexities of sonar, it is important to understand the properties of sound. Sound is a pressure wave that travels when molecules collide with each other. We know that sound can travel in air, because we experience this every day when we talk to each other, but it can also travel in liquids and solids (which whales rely on to communicate). As a general rule, sound travels much faster in liquids and solids than in air because the molecules in liquids and solids are closer together and therefore collide more often, passing on the vibration at a faster rate. (The average speed of sound in air is about 343 meters every second, whereas the approximate speed of sound in water we have been measuring is around 1475 meters every second). Within a non-uniform liquid, like saltwater, the speed of sound varies depending on the various properties of the saltwater at the survey site. These properties include water temperature, dissolved impurities (i.e. salts, measured by salinity), and pressure. An increase in any of these properties leads to an increase in the speed of sound, and since we’re using the equation distance = speed * time equation, it is crucial to consistently measure them when seeking depth measurements.

CTD Data
Data from CTD showing temperature vs. sound speed from one data set. Notice how the temperature and sound speed seem correlated.

To measure these properties, a device called a CTD (Conductivity-Temperature-Depth) is used. Conductivity in this acronym refers to the free flowing ions in salt water (Na and Cl, for example), which are conductive and the concentration of these ions determines the salinity of the water. The CTD measures these three properties (Conductivity, Temperature and Depth) so the speed of sound in the water can be calculated at every point in the water column

To use the CTD, lovely humans like Avery and I will drop it into the water (it is attached to a winch system) at the area where we are surveying and as it travels to the sea floor, it takes a profile of the three saltwater properties mentioned before. Back in the computer lab, software takes this profile data and and calculates the sound velocity or speed of sound through the water in that region.  As a crosscheck, we compare our profile data and sound velocity figures obtained at the site to historical measured limits for each property. If our measurements fall significantly outside of these historical values, we might try casting again or switch to a different CTD. However, because we are surveying in such a remote area, in some cases, data outside historical limits is acceptable.

CTD graphs
Graph of our sound speed vs. depth data showing comparison to historical data.

Given that we are trying to determine the water depth to within centimeters, variations in the sound speed profile can cause substantial enough errors that we try to take a “cast” or CTD reading in each small area that we are gathering data. The software the survey team uses is able to correct automatically for the sound velocity variations by using the data from the CTD. This means that the depth profile created by the sonar systems is adjusted based on the actual sound velocities (from the CTD data) rather than the surface sound speed. We are also able to account for speed changes that would cause refraction, or a bending of the beam as it travels, which would otherwise provide inaccurate data about the location of the sea floor.

Rosalind CTD 1
Rosalind lowers the CTD into the water for a “cast”. The CTD needs to sit in the water for a few minutes to acclimate before being lowered for a profile.

Rosalind CTD 2
Rosalind operating the winch on to pull the CTD back up out of the water. It’s important to pay attention to the flexible white bar to make sure the CTD isn’t caught on anything at the bottom.

Rosalind CTD 3
Rosalind pulling the CTD out of the water, successfully taking a cast and not falling in the water. Safety first!

Did you know? Sonar works a lot like the echo sounding of a bat, and its development was partially prompted by the Titanic disaster.

Personal Log:

On a ship with a crew of more than 50 people, you encounter people with a wide variety of backgrounds and stories about how they came to be here. Whether it is the NOAA corps officers, the members of the deck department, the engineers, the stewards and cooks, or the members of the hydrographic survey department, each person has a unique life experience that led them to be here on the Rainier. The advantage of being in close quarters for three weeks is that there are lots of opportunities to talk to people about what brought them here. Contrary, I think, to the messaging we sometimes get about needing to pick a life path early and stick to it, the people here have shown me the importance of being flexible and leaving yourself open to new and exciting opportunities professionally. One of the current members of the deck department was also in the navy for a long time, served several tours in Iraq and was trained as a Navy diver. Now, he is moving over to the survey department, and will be attending the NOAA dive school and hydrographic training this fall and winter, which I think is amazing. Case in point: it’s never too late to change your mind about what you want to do with your life.

Rocky shoreline
One of the many stunning views we have seen during our surveying activities.

In these conversations, it always comes out that I teach students physics. Regardless of the job someone does here on the Rainier, it seems inevitable that each person has a story about his or her own experience with physics. It seems that in the majority of cases, even for people who are now very successfully scientists, the experience was not positive. People all the time tell me that they didn’t really understand physics, or weren’t a physics person, and yet this same person can explain in great detail how we can use the ship to create a “duck pond” to bring in the launches in foul weather, or fix the engine of one of the launches, or determine the appropriate course of the ship to account for the swell and current to head in a particular direction. All of these unquestionably involve an application of physics, which suggests to me that the issue is not necessarily that physics is beyond some people, but that we don’t always teach students in ways that will work for them. This certainly gives me a lot to think about as a teacher, and hopefully I can maintain this awareness in my teaching.

Avery Marvin: Excited for this upcoming adventure! July 1, 2013

NOAA Teacher at Sea
Avery Marvin
(Almost) Onboard NOAA Ship Rainier
July 8–25, 2013

Mission: Hydrographic Survey
Geographical area of cruise: Shumagin Islands, Alaska
Date: July 1, 2013

Greetings from the Oregon Coast! Thank you for visiting my blog, and I hope you continue to follow me this summer throughout my 18-day Alaskan adventure aboard the NOAA ship Rainier. I am elated and honored to be a NOAA Teacher at Sea—an experience that will undoubtedly shape me and my classroom instruction for years to come.

NOAA Ship Rainier
NOAA Ship Rainier

My name is Avery Marvin and I am a middle school General Science and high school Biology teacher at Taft 7-12, a mid-size public MS/HS in Lincoln City, on the Oregon coast. I moved here just one year ago, and have been discovering the unique facets of living and teaching in a coastal community ever since.  I continue to be amazed and inspired by the natural surroundings and marine resources (i.e. the NOAA base in Newport, Hatfield Marine Science Center) at my fingertips. Knowing I am New York native, many of my students have quizzically asked me, “Ms. Marvin, why did you move here?” My hope, then, is that through this NOAA experience, I will be further able to inspire and show kids that “here” is a pretty amazing place to be—not just in terms of its natural beauty but its ecological and research significance moreover. With this awareness and education, students hopefully will feel a greater sense of ownership of—and thus appreciate and actively protect—the greatest resource in their very backyard: the ocean.

Diving in Tasmania
Avery dives in the chilly waters of Tasmania, Australia

As an avid adventurer and ocean-goer, I have explored many waters both as a conservationist and a recreationist (i.e. scuba diver, fisherwoman). Yet Alaska is a place I have dreamed of visiting for most of my life, and to be able to combine my experience with like-minded scientists conducting vital ocean research is truly awesome to me.  The Rainier, homeported at the NOAA Marine Operations Center – Pacific in Newport, Oregon, is a hydrographic surveying ship whose primary focus is mapping the sea floor in coastal areas.  The depth data collected on the Rainier is used to update nautical charts. This is crucial work as commercial shippers, passenger vessels and fishing fleets rely on accurate nautical maps to safely traverse various ocean passages.  In the case of Rainier’s work in Alaska, some of the terrain is being surveyed for the first time. Rear Adm Gerd Glang, director of Coast Survey, sums it up best, “Simply put, we have better maps of the moon than of our oceans.”  Several multi-beam sonar systems located on the Rainier as well as on a few smaller launch boats are employed to acquire this mapping data.  This six-minute video  gives a good overview of the mission and daily operations of the Rainier.

My 18-day journey begins on July 8, 2013 in Kodiak, Alaska, where I will be meeting up with the Rainier.  From Kodiak, we travel southwest to the Shumagin Islands, where the majority of the research on this leg of the trip will be conducted. We will then conclude our journey back in the Kodiak port. (Track Rainier’s movement here.) I can’t wait to dive in and absorb all that I can. I am particularly looking forward to working with and learning from all the scientists onboard, seeing the majestic Alaskan landscape and understanding how survey data can be used for mapping vital fisheries habitats.

I hope you will ‘virtually’ join me aboard the Rainier, this summer, and be a witness to some incredible scientific research.  This blog will be updated weekly with interesting stories, pictures and lots of newfound information about our mission at sea.  So check back often and feel free to leave comments and questions for me. If I don’t know the answer, I will ask a brilliant scientist to help me.

“For most of history, man has had to fight nature to survive; in this century he is beginning to realize that, in order to survive, he must protect it.” -Jacques-Yves-Cousteau

Adam Renick, The DIDSON Pilot, June 21, 2013

NOAA Teacher at Sea
Adam Renick
NOAA Ship Oscar Elton Sette
June 12th – June 26th, 2013 

Mission: Kona Integrated Ecosystems Assessment http://www.pifsc.noaa.gov/kona_iea/
Geographical area of cruise: The West Coast of the Island of Hawaii
Date: Friday, June 21, 2013

Current Air Temperature: 75° F
Sea Surface Temperature: 77° F
Wind Speed: 16 knots

Happy Solstice Everybody! Welcome to astronomical summer!

Giacamo Giorli explains the DIDSON deployment process to the team.
Giacomo Giorli explains the DIDSON deployment process to the team.

What is a Didson?

The DIDSON sonar in a protective case.
The DIDSON sonar in a protective case.

We are well into the second week of our cruise and I want to tell you all about a new pilot project that NOAA is working with through the Marine Mammal Research program at the Univ. of Hawaii that is using a DIDSON sonar. A DIDSON (Dual frequency IDentification SONar) is an advanced type of sonar that has many advantages over a traditional sonar for finding fishes and other marine life.

Images of fish on a DIDSON . http://www.adfg.alaska.gov/index.cfm?adfg=sonar.didson
Images of fish on a DIDSON . http://www.adfg.alaska.gov/index.cfm?adfg=sonar.didson

The first advantage of a DIDSON is that it gives us a very highly detailed image of what types of marine life are present in the water. When our shipboard acoustics team “sees” that there is a layer of creatures in the water column it appears as very small dots on a computer screen.

Here you can see the DIDSON going down to record the scattering layer (the very thin line near the finger).
Here you can see the DIDSON going down to record the scattering layer (the very thin line near the finger).

This is great because it tells us the depth and location, but it does not tell us what it is. When we see something of interest, we can deploy the DIDSON to give us an actual “picture” of that creature or even a video of its behavior. The reason I am describing the “imaging” properties of this tool in quotes is that it is not a camera and it does not use light to see at all. Rather, it uses high frequency sound waves to produce an image much like a sonogram gives us a picture of a baby in a mother’s uterus.

Comparison of different types of sonar.
Comparison of different types of sonar.

This leads us to another major advantage of the DIDSON over traditional technologies such as beam sonar or videos. This thing can go very deep into the ocean to explore the life that is there. If you recall back to my previous post you will remember that mesopelagic fish hang out much deeper in the water column during the day than at night. Trawling that deep is challenging and requires more effort and resources than using the DIDSON. If we want to see what is down there we can deploy the DIDSON into the scattering layer and get a sense of the marine life in the deeper parts of the ocean. Also, because it uses sound it can give us data about behaviors that are occurring in the dark regions of the ocean.

Mr. Giorli wishing luck to the DIDSON equipment as it is deployed.
Mr. Giorli wishing luck to the DIDSON equipment as it is deployed.

Giacomo Giorli and others that are leading this project on the cruise are still going through the data they’ve collected with the DIDSON.  So far, they have seen a lot of success and have a identified a few squids – but they won’t tell us more than that until they go back to the lab to fully analyze their data.  “We don’t exactly know what is down there right now, but with emerging technology, one day we will,” says Mr. Giorli. See a video clip of the DIDSON data here.

The ever-useful duct tape makes its debut on this cruise.
The ever-useful duct tape makes its debut on this cruise.

Eric Velarde: Rosette C.T.D. Analysis & HabCam V4 Operation, June 15, 2013

NOAA Teacher at Sea
Eric Velarde
Aboard R/V Hugh R. Sharp
Wednesday, June 13, 2013 – Monday, June 24, 2013

Mission: Sea Scallop Survey
Geographical Area: Cape May – Cape Hatteras
Date: June 15, 2013

Weather Data from Bridge
Latitude: 38°19.0778 N
Longitude: 74°15.9625 W
Atmospheric Pressure: 30.7in
Wind Speed: 11.5 Knots
Humidity: 70%
Air Temperature: 66.4°F
Surface Seawater Temperature: 66.2°F

Science & Technology Log

Deploying the Rosette to collect the first water sample for C.T.D. analysis & flying the HabCam V4 was the focus of work on June 15, 2013. The Rosette is deployed so that water samples can be collected to analyze the Conductivity, Temperature, and Depth (C.T.D.) of the seawater, providing data on the physical aspects of the Atlantic Sea Scallop’s (Placopecten magellanicus) habitat. The engineering team assumes responsibility of the Rosette, which is carefully lowered into the ocean through winch operation on the bridge. Once the Rosette has reached near the seafloor, it collects seawater and is then carefully retrieved through winch operation on the bridge. The seawater is then collected into an individual sampling bottle for analysis & calibration of the instrument.

Rosette C.T.D. Apparatus
Rosette C.T.D. Apparatus

Digital image rendering of the C.T.D. analysis allows for graphic visualization of the gathered oceanographic information, as well as calibration of the instrument. Analyzing the information demonstrates the two distinct layers of the ocean, separated by a relatively abrupt dividing boundary, which defines them. Atlantic Sea Scallops (Placopecten magellanicus) inhabit the seafloor in the lower layer of the ocean, whereas Plankton and Sea Scallop larvae can be found in the upper layer. Presentation of the C.T.D. readout gives accurate data of the Voltage (purple), Oxygen (blue), Temperature (red), and Salinity (green) levels.

C.T.D. Readout
C.T.D. Readout

As stated in my previous post, the HabCam V4 takes a tremendous amount of teamwork in order to operate at its maximum capacity. Correspondence with the engineering team is required to launch & retrieve the HabCam V4, the pilot must remain focused on ensuring that the HabCam V4 is close enough to the seafloor for maximum image quality, while at the same time being at a safe distance to prevent accidental collision, and the co-pilot is focused on incoming images & server traffic at a 2-monitor interface. All participating members of the crew must be attentive, communicative, and actively engaged in the contributing activities of other team members at all times.

HabCam V4 Co-Pilot Interface
HabCam V4 Co-Pilot Interface

The best way to describe piloting the HabCam V4 is to compare it to a video game, albeit one that has no “extra lives”. There is a pressure sensitive fiber optic cable feed & retrieval control lever that allows the pilot to either decrease or increase the depth of the HabCam V4. It is vital to maintain a safe distance while being in close enough range of the seafloor so that the incoming images are properly exposed and recognizable for the co-pilot. The optimum range is between 1.7 – 1.9 meters +/- 0.2 meters. Piloting the HabCam V4 during satisfactory weather is nearly effortless once having become acclimated to the 5-monitor interface and the control lever. Piloting the HabCam V4 during foul weather is quite difficult, requiring constant conscious concentration on all variables (seafloor depth, HabCam V4 depth, sonar readout, and fiber optic cable feed & retrieval) in order to prevent an accidental collision with the seafloor.

HabCam V4 Piloting
HabCam V4 Piloting

Co-piloting the HabCam V4 requires attention to the incoming images, as well as server traffic. Incoming images must be screened so that identified individual species can be time-stamped and tagged for analysis. Using software, the co-pilot can either tag observed species using digital identification markers, or manually input text to identify a particularly intriguing image that they wish to highlight for analysis. It is important to ensure that incoming images are being written to the server for digital archiving and future annotation. Digital data management, a scarcely celebrated 21st century character trait, is one of the many strengths of the crew aboard this vessel.

HabCam V4 Co-Piloting
HabCamV4 Co-Piloting

Personal Log

Despite a few bouts of violent seasickness, I have been having the time of my life while aboard the R/V Hugh R Sharp. The crew possesses seemingly infinite amounts of sincerity, honesty, and intelligence. The continued operation of this wonderfully engineered human machine has occurred without error, and will continue to do so while under the watchful eyes of the leadership heads. Thus far my favorite aspect of this research experience has been co-piloting the HabCam V4. Having vast amounts of digital imagery stream before my observation makes me feel as though I am at home, screening digital images that I stumble upon for both scientific beauty & significance.

HabCam V4 Co-Piloting
HabCam V4 Co-Piloting

In addition to the technological aspects of this experience, I have also found solace in the empathetic energy provided by the ship’s captain, Jimmy Warrington. His humor, experience, and leadership create an ideal teaching & learning environment. While many may dread the monotonous nature of a safety briefing, the one provided by the Captain was both engaging and informative. Following safety briefing, newcomers to the R/V Hugh R. Sharp are required to don a safety immersion suit in less than 60 seconds. The safety immersion suit is more commonly referred as a “Gumby Suit”. The suit is quite impressive, being both insulating and buoyant. It possesses a safety whistle, flashlight, interpersonal locking hooks, and even an inflatable pillow. It is reassuring to know that above all else, safety is the primary focus of the leadership on this vessel.

Safety Immersion Suit or "Gumby Suit"
Safety Immersion Suit or “Gumby Suit”

Being on duty from Midnight-Noon causes me to miss the opportunity to observe sunsets at sea on most nights, but I have been able to experience a few and they are simply the most breathtaking sunsets that I have ever seen. Watching the night divide the day is both awe-inspiring and thought provoking. Despite my colorblindness, I feel that I am still capable of absorbing all of the electromagnetic energy that the sun provides during this hour of magic.

Sunset Storm
Sunset Storm

Dredge tows will be the focus of upcoming days, and is something that I am looking forward to. As a biologist, I find all living organisms infinitely beautiful and stimulating. I cannot wait.

-Mr. V

Did You Know?

The Atlantic Sea Scallop Fishery is the largest & most valuable scallop fishery on planet Earth, valued at $580,000,000 in 2011.

Marla Crouch: Gumbi Marla and Setting Course, June 18, 2013

NOAA Teacher at Sea
Marla Crouch
Aboard NOAA Ship Oscar Dyson
June 8-26, 2013 
 

Mission: Pollock Survey
Geographical area of cruise: Gulf of Alaska
Date: June 18, 2013

Weather Data from the Bridge: as of 1900
Wind Speed 13.48 kts
Air Temperature 7.0°C
Relative Humidity 99.00%
Barometric Pressure 1,010.00.5 mb

Latitude:  54.31N   Longitude: 159.80W

Science and Technology Log

Another fashion statement – Gumbi Marla

Here I am, all zipped up in my immersion suit.
Here I am, all zipped up in my immersion suit.

I’ve donned an immersion suit, also known as a survival suit.  One of the first things I did when I came aboard was to locate this suit and my life vest, two pieces of equipment that save lives.  In the event we had to abandon ship, the survival suit would keep me both warm and afloat until rescue.  During our evacuation drill we needed to unpack and get into the suit, and be completely zipped up in 60 seconds or less.  Getting into the suit was much easier after I took my shoes off, as the soles caught on the fabric of the suit.  The suit is made of neoprene, which was invented in 1930.  SCUBA wetsuits are also made of neoprene, and even some laptop and tablet cases.

In an earlier blog I talked about the CTD being used to calibrate the sonar aboard the Oscar Dyson, but not all technologies on the Dyson are as high tech as the CTD and sonar equipment.  In fact you can build a weather station at home that is similar to some of the equipment used by the Dyson’s crew.  Below is a picture of a hygrometer.  There are actually two hygrometers aboard, one is located on each side of the bridge.  Hygrometers are used to measure relative humidity (how much moisture is in the air).   Also pictured is the wind bird which shows the direction the wind is moving.  The propeller was actually turning rapidly when the picture was taken.  The camera was able to “stop” the action.  The wind bird is mounted atop the jack staff, high above the bow.

Hygrometers are weather instruments used to measure relative humidity.
Hygrometers are weather instruments used to measure relative humidity.

Wind bird

The following link shows you how to build six instruments for monitoring the weather.

http://oceanservice.noaa.gov/education/for_fun/BuildyourownWeatherStation.pdf

If you checked out the above link, how many snow days to you think the kids in North Dakota had?

Did you check out ship tracker?  If you did, the screen shot below will look familiar.  The blue lines in the water display the Dyson’s course.  Each segment of the course is called a transect.  Transects are numbered, enabling scientists to easily reference a location.

Oscar Dyson's course as of 6 18 13
Oscar Dyson‘s course as of 6 18 13

Are you wondering why we have traveled in rectangular patterns?  The scientists establish this course for a several reasons:

  1. Transects run perpendicular to the coast line, covering a wide range of bathymetry over the shortest distance.
  2. Regularly spaced transects (as opposed to randomly spaced or scattered) are correlated with historical data, and are the best way to describe the distribution of pollock.
  3. The combination of transects collects sufficient data to allow scientists to estimate the overall size of the pollock population with a high degree of certainty.

Does anyone have an idea about the meaning of “bathymetry” and a “leg”?  No, in this case a leg is not something you stand on.  Bathymetry is the shape and depth of the ocean floor, and a bathymetry contour line on a chart connects points of equal depth (like a topographic map).  A leg, in this context, is a segment of the overall distance covered in the survey.

The information collected during this year’s survey helps determine the number of pollock that can be caught in next year’s fishing season.

Here is the ship tracker link, you can check out the Dyson’s course and other NOAA ships as well.

http://shiptracker.noaa.gov/shiptracker.html

Personal Log 

I want to revisit the sonar of Mystery Mix One.  In my last blog I talked about what was happening near the surface of the ocean.  This time I want to focus beneath the sea floor.

Graphic provided by NOAA
Graphic provided by NOAA

Look beneath the red, yellow, and green bands, depicting the sea floor, at the blue color, notice how the density of color changes over time.  The density of the color tells scientists about the composition of the sea bed.  The denser the color, the denser or harder the seafloor is likely to be; probably, the places with the dark, dense color are rocky areas, which attract the fish schools seen in the water above.

Looking at this graph reminds me of an experiment that my husband worked on, when he worked for Charles Stark Draper Labs, in Boston, MA.  He worked on a Gravity Gradiometer that was sent to the moon on Apollo 17.  The gradiometer measured the changes in gravity.  The changes in gravitational strength give scientists information about what lays beneath the moon surface, like the sonar provides information about the sea bed.  The Gravity Gradiometer was a very specialized version of equipment that is commonly used in prospecting for oil on Earth.  I am sharing this story because, in class, one of our foci is to take what we know and apply the knowledge to a new scenario.  Next question:  Where will what we know now, take us in the future?

Did You Know?

Some fish can see color.

Marla Crouch: The Mystery and Surf Your Berth, June 14, 2013

NOAA Teacher at Sea
Marla Crouch
Aboard NOAA Ship Oscar Dyson
June 8 – 26, 2013 

Mission:  Pollock Survey
Geographical area of cruise:  Gulf of Alaska
Date: June 14, 2013

Weather Data from the Bridge: as of 1900
Wind Speed 9.57 kts
Air Temperature 6.84°C
Relative Humidity 81.00%
Barometric Pressure 1,030.5 mb

Latitude:  53.52N   Longitude: 166.34W

Science and Technology Log

The sonar on the Oscar Dyson recently created the graph below.  The graph displays the sea floor, the red, yellow, and green bands toward the bottom and along the top a few meters from the surface the layer of green and red, is the mystery.

Graphic provided by NOAA
Graphic provided by NOAA

The echoes, that create the graph do not look like fish.  The scientists recognize that something is there, the questions is, what?  Further exploration is done, but nothing definitive is found. This creates a bit of a dilemma, which initiates a whole series of conversations about trouble shooting the equipment, using different data gathering techniques (something different than a trawl), and hypothesizing about what is creating the image since there are no apparent biology.  Could the image be created by something physical in the water?  Until the make-up of the image can be identified the sonar signature, is titled and recorded as Mystery Mix One.

Taina Honkalehto, one of the scientists on this cruise, tells me that they have been encountering Mystery Mix One for a number of years here, in the Gulf of Alaska, and in different parts of the ocean at different times of the year. Mystery Mixes Two and Three are floating around as well.

Investigating Mystery Mix One:  Time stamp 12 June 2013, 050952 GMT (This time stamp equates to 8:09 almost 8:10 p.m. June 11, 2013 PDT.)

The stereo camera, which I talked about in my last blog, is a new piece of equipment that scientists are using to collect data about the ocean floor and the biology of the region.  The stereo camera was launched and submerged to a depth of 50m into the middle of Mystery Mix One, and left at that depth for 30 minutes while the Oscar Dyson drifted with the mix.  When the pictures were downloaded, the only identifiable objects were copepods, big copepods. Remember “big” is a relative term, big compared to what? Copepods can be smaller than 1 mm in length.  These big copepods are probably 6 to 8 mm.

The light image in the upper left-hand corner is a copepod.  Picture provided by NOAA
The light image in the upper left-hand corner is a copepod. Picture provided by NOAA

This is a clearer picture of a copepod. This is a clearer picture of a copepod.     Picture courtesy of comenius.susqu.edu
This is a clearer picture of a copepod.
Picture courtesy of comenius.susqu.edu

The strong sonar image created by the copepods heighten the mystery; starting another round of questions and discussions by the scientists.  Why are copepods creating such a strong sonar signature?  Why are the copepods so prominent on 18 kHz? (18 kHz is a low frequency that usually captures echoes from large objects, while small things like copepods would be seen at higher frequencies, like 200 kHz.)   Could something else be in Mystery Mix One, something that was not seen by the camera?  The discussion goes on creating a working hypothesis; the signature is being created by a combination of the copepods themselves, whatever they are feeding on and gases, being produced.  Not all the scientists are in agreement.  If Mystery Mix One was to be sampled again, would you get similar results?

Pictures from the stereo camera provided one piece of possible evidence that may lead to answering the question, “What is in Mystery Mix One?”

The next day another piece of possible evidence is added.  Oscar Dyson’s sea water intake filter is cleaned and what is found?  Krill and big copepods.  Pictures are taken and the evidence is recorded in the scientists’ journal. More evidence needs to be collected, but advances are being made to identify Mystery Mix One.

Krill are in the red ringed filter.  Copepods can be seen at the bottom of the bucket.
Krill are in the red ringed filter. Copepods can be seen at the bottom of the bucket.

Personal Log 

The first few days out at sea the waters were really calm, 1 to 3 foot swells or seas, which feels like the soothing glide of a rocking chair.  Now however, weather is moving in; wind speed is up around 15kts and the swells are about 9 ft.  Friday’s forecast is for 30kt winds and 12ft. seas.  Looking at the big picture, 9 to 12 foot seas are not very big.  But, walking around the ship with seas of that height requires due diligent to safely navigate the passage ways and steep stairs.  And you definitely need to mind the doors, make sure the door is securely latched and when opening hold on tight, as you don’t want the door to get away from you. Somebody might be standing on the other side.  Another activity that can prove challenging is getting into and out of your bunk.

The berths, or rooms, aboard ship are, for the most part, designed for two people. Look at the picture of my berth.  You can see a desk, chair, dresser and two draped bunk beds.  Mine’s the top bunk.  Our room is just about even with the water line.  That is important to know, because the lower you are in the ship the less dramatic the motion.  I’ll talk about the pitch and roll of the ship in a future blog

This is my berth.
This is my berth.

Now imagine yourself lying on a teeter totter.  You are right above the fulcrum, so you are nice and level.  An unbalanced force is now affecting your teeter totter, your feet go up your head goes down and you slide a little.  Then there is a change and you head goes up your feet go down and you slide back.  This back and forth motion is continuous, and the motion presses you into the teeter totter.  I call this the sloshing phenomena, because all the while you are teeter tottering you hear the sea water rushing pass the hull.  But wait, there is more.  Your teeter totter only moves in two dimensions, but we live in three dimensions.  Keep your teeter totter going, up and down, hear the water stream by and add a sideways roll, back and forth.  Don’t fall off your teeter totter.  You are not quite ready to surf your berth yet, sometimes the up and down, and side to side movements occur so quickly that you actually loose contact with your teeter totter.  Now you’re surfing!  I have yet to find the seat belt for my bunk.

Remember I said that my berth was low in the ship, there are only a few berths on this level, and more berths are two and three floors above me. Now think about a metronome.  If you’re not sure what a metronome is think about a windshield wiper on a car.  Both the metronome and the windshield wiper make small movements at the pivot point or fulcrum; the further away from the fulcrum the greater the range of motion. Think about how the motion is magnified as you move up from the water line.  Those folks above me are really surfing.

Did You Know?

When Taina and I were talking about Mystery Mix One she said the 18 kHz frequency ensonifying the larger fish.  I think ensonify is a cool word. I wonder if Mrs. Sunmark or Mrs. Delpez (our school’s band and orchestra teachers) have used the word ensonify in their classes?  Can any of you tell me what ensonify means?

Did you know you can follow my voyage on NOAA’s ship tracker website?  Here is the link.

http://shiptracker.noaa.gov/shiptracker.html

In my next blog, I have another fashion statement – Gumbi Marla!  And maybe something about the moon and Apollo 17.


Eric Velarde: First Day at Sea & HabCam V4 Operating Systems Management, June 13, 2013

NOAA Teacher at Sea
Eric Velarde
Aboard R/V Hugh R. Sharp
Wednesday, June 13, 2013 – Monday, June 24, 2013

Mission: Sea Scallop Survey
Geographical Area: Cape May – Cape Hatteras
Date: June 13, 2013

Weather Data from Bridge
Latitude: 38°47.3002 N
Longitude: 75°09.6813 W
Atmospheric Pressure: 30.5in (1032.84mb)
Wind Speed: 14.5 Knots (16.68mph)
Humidity: 70%
Air Temperature: 19.2°C (66.6°F)
Surface Seawater Temperature: 19°C (66.2°F)

Bridge Weather Data Collection
Bridge Weather Data Collection

Science & Technology Log

Cleaning, stabilizing, and testing the Habitat Mapping Camera System, or HabCam V4 was the focus of work on June 13, 2013. This work was done to ensure that all image collection & processing during the Sea Scallop Survey proceeds without any technical mishaps. Following cleaning, the HabCam V4 fiber optic cable needed to be stabilized to minimize vibrational interference using an ingenious combination of copious amounts of galvanized electrical tape & zip-ties. Once the HabCam V4 fiber optics cable was properly stabilized, the vessel set out to sea to conduct preliminary testing to ensure that all systems were operating properly.

Stabilizing the HabCam V4 Fiber Optic Cable
Stabilizing the HabCam V4 Fiber Optic Cable

What distinguishes the HabCam V4 from other HabCam systems is that the HabCam V4 records Stereo-Optic images (3D images) using 2 cameras in order to give an unprecedented view of the ocean floor organisms and their habitat substrate in the highest image quality available. In addition, the HabCam V4 also possesses a side scan acoustics system, which allows the HabCam V4 Pilot (AKA, “Flyer”) to visualize the sea floor using Sonar technology. Visualizing the sea floor using Sonar allows for more precise HabCam V4 flying so that the HabCam V4 is kept at a safe  distance from the sea floor, which is contoured similarly to Earth’s continents.

HabCam V4 Pilot Interface
HabCam V4 Pilot Interface

Flying the HabCam V4 requires tremendous amounts of teamwork, as there are several operations that must occur simultaneously to ensure seamless HabCam V4 winch operation, data retrieval & image annotation. The Pilot is stationed behind a 5 screen interface where the following information is received: fiber optics cable feed & receival (smaller, upper left screen), loading deck real-time camera feed (upper left screen), Sonar visualization (upper right screen), altimeter/fathometer data (lower left screen), and HabCam V4 real-time image feed (lower right screen). The HabCam V4 is controlled in the Dry Lab by the Pilot who uses the interface to determine how much of the fiber optics cable is needed to be fed or received so that the HabCam V4 remains at a safe distance from the sea floor.  A winch operator is stationed on the loading deck to assist in managing fiber optics cable feed & retrieval. In addition to piloting and winch operation, a co-pilot works at a 2 screen interface to monitor the movement of the HabCam V4 relative to the vessels motion, as well as annotate the incoming images in real time so that observed organisms can be categorized, flagged, and timestamped.

Vic & Amber Piloting/Co-Piloting HabCam V4 in Dry Lab
Vic & Amber Piloting/Co-Piloting HabCamV4 in Dry Lab

Due to incoming severe weather & HabCam V4 data retrieval complications, the vessel had to return to port in Lewes, DE to ensure the safety of all crew members & scientific technology. The vessel is set to return to sea once the seas have calmed down and when the HabCam V4 is at its full operational capacity.

Incoming Severe Weather
Incoming Severe Weather

Personal Log

This experience seems like a living dream. Flying from Raleigh-Durham International Airport into Philadelphia International Airport was a breathtaking flight. The clouds were wispy, full, and complex. My mind was filled with anxious anticipation, and perhaps quixotic wonder & awe. As the plane descended, I was still wandering in the clouds in my mind. Even the drive from Philadelphia to my hotel in Rehoboth, Delaware where I spent the night before boarding the vessel seemed to be filled with restless excitement.

Philadelphia Clouds
Philadelphia Clouds

I’ve been working hard to become well acquainted with everyone and everything on board. This has already become a life changing experience for me. I have never had the opportunity to eat, sleep, and work in such an immersive scientific environment until this experience. Being in such close proximity to other scientific minds is very fulfilling, providing transcendental feelings of scientific curiosity, sincerity, and beauty. My natural tendency to introvert has begun to fade and I cannot stop the feeling of wanting to contribute as much as possible to the successful operation of the vessel and our mission.