Joan Shea-Rogers: Do You Hear What They Hear, July 8, 2018

NOAA Teacher at Sea

Joan Shea-Rogers

Aboard NOAA Ship Oscar Dyson

July 1-22, 2018

Mission: Walleye Pollock Acoustic Trawl Survey

Geographic Area of Cruise: Eastern Bering Sea

Date: July 8, 2018

Weather Data from the Bridge

Latitude: 53º N

Longitude: 166ºW

Sea Wave Height: 1.5 feet

Wind Speed: 25 Knots

Wind Direction: SW

Visibility: 15 miles

Air Temperature: 52ºF

Water Temperature: 46º F

Barometric Pressure: 1010.61mb

Sky: Overcast

Science and Technology Log

What kinds of fish live in the Bering Sea? How many pollock are in the Bering Sea? Where are the pollock in the Bering Sea? How big are the pollock in the Bering Sea?

Those are just a few of the questions that the fisheries biologists on NOAA Ship Oscar Dyson work to answer during each voyage. In my last blog, I talked about the need to manage the pollock fishery in order to protect this important ocean resource because it provides food for people all over the world. It is important, then, to be able to answer the above questions, in order to make sure that this food source is available each year.

How do they do it? There are two main sources of information used in the Acoustics-Trawl (or Echo Integration Trawl) survey to determine the abundance and distribution of pollock in a targeted area of the Bering Sea. One is acoustics data, and the other is biological-trawl data.

Acoustics:

Acoustic data is continuously collected along a series of parallel transects with a Simrad EK60 scientific echo integration system incorporating five centerboard-mounted transducers (18-, 38-, 70-, 120-, and 200- kHz). In other words: There are 5 sound wave producers (transducers) attached to the bottom of the ship, each one emitting sound waves at different frequencies. This allows scientists to look at different organisms in the water column. Different types of organisms reflect different amounts of energy at different frequencies. The amount of acoustic energy reflected by an individual animal is called the target strength, and is related to the size and anatomy of the species. For example, a fish with a swimbladder (like pollock) reflects more energy than a fish without a swimbladder because its properties are very different from the surrounding water. Some ocean dwelling organisms don’t have swim bladders. Flatfish stay on the bottom so they don’t need the buoyancy. Floating organisms like jellyfish don’t have them. These organisms will look differently than pollock on an echogram because they have a smaller target strength.

Transducer

Transducer

Transducers convert mechanical waves (sound waves) into an electrical signal and vice versa (like both a loudspeaker and a microphone combined). They contain piezoelectric materials sensitive to electricity and pressure: if a voltage is applied to them, they make a pressure or sound wave (transmit), and when a sound wave passes over them, it produces a voltage (receive). When a sound wave (echo from a fish) is received, electoral signal is sent to a computer, which displays the signals as pixels of varying colors as the ship moves along (depth changes up and down on the left of the image, and time and location changes along the bottom of the image). This datum is used to estimate the number and type of fish in the water column, and to determine where the ship should fish next.

The size and colors on the images (called echograms) represent the backscatter at different depths and is related to the density of fish and their target strength. But, since they are dots on a screen, specific identification is not possible. The scientists assume certain strong signals are pollock based on the information they have but, those dots could be other fish. To determine what kind of fish are in the water column at this location, how many are there, and how big they are, other data must be obtained. Biological Trawl Data provides that additional information. More about that in my next blog post……I bet you can’t wait!

Personal Log

The Calm Before the Storm:

So far my trip has been smooth sailing, literally. As NOAA Ship Oscar Dyson sails across the Bering Sea there is a bit of rocking the ship experiences at all times. This is easy enough for one to get used to and sometimes it even becomes comforting, like being rocked to sleep as a child. You adjust to the motion. Over the past couple of days I have been hearing talk of a storm coming our way. On a ship, there are many preparations that occur in order to get ready for a storm. Many items are always secured, such as shelves that have a wall in front so that things don’t fall off. There are “handle bars” in showers and next to toilets (think about that). Along hallways and stairways there are handrails on each side. Mini refrigerators in staterooms are bolted to walls. In fact most things are bolted to walls or stored in containers that are bolted to the wall. In the mess hall (dining room) condiments on tables are in a box so they can’t slide off.

Why do you think this coffee mug is shaped like this (wider at the bottom than the top)?

 

At-Sea Coffee Mug

At-Sea Coffee Mug

Ans. The wider bottom of the mug above prevents it from sliding as the ship rocks.

Our bulletin board reminds us to secure for bad weather. This morning, I put small items in drawers, stowed books on shelves and packed my equipment (phone, laptop, camera, chargers and small items in a backpack that can be safely secured in my locker (the “closet” in my stateroom).

In talking to my shipmates with at sea experience, I am getting lots of helpful hints about storm preparations and strategies to use during the storm. Here are some of those suggestions:

*always hold on to railings with both hands when walking or going up steps. At all other times, remember to keep one hand for you (to do whatever you are doing) and one hand for the ship (to hold on).

*keep something in your stomach at all times, even if you are not feeling well

*eat saltines

*drink lots of water

*when sleeping in your bunk, place pillows between you and the edge so as not to roll off (I will definitely follow this one, as I am on the top bunk) It also depends upon which direction the ship is rolling. Pillows may need to be put between your head and the wall to prevent head bumps

*go to the lower parts of the ship because the top part will sway more with the waves

I also have been wearing patches to prevent seasickness. Hopefully they will continue to help. Only time will tell how we weather the storm (pun intended). Let’s hope it moves through quickly.

 

 

 

 

 

 

 

 

Lee Teevan: Getting Schooled in the Nature of Science, July 8, 2018

NOAA Teacher at Sea

Lee Teevan

Aboard NOAA Ship Oscar Dyson

July 1 – 21, 2018

Mission:  Pollock Acoustic-Trawl Survey

Geographic Area of Cruise: East Bering Sea

Date: 8 July 2018

Dutch Harbor, AK

This is a view approaching Dutch Harbor, AK.

 

Weather Data from the Bridge

Latitude: 66 N

Longitude:  166 W

Sea Wave Height: 2ft

Wind Speed: 25 knots

Wind Direction: SW

Visibility: 15 miles

Air Temperature: 52°F

Barometric Pressure: 1010.61 mb

Sky: overcast

Science and Technology Log

Although July has just begun, teachers are already anticipating the first day of school.  Like every science teacher, we launch our classes with the “Nature of Science” or the “Scientific Investigation.”  Unlike past years, I plan on contextualizing these topics by showing my students the  “scientific investigation in action”  by describing how scientists aboard the Oscar Dyson studying eastern Bering Sea pollock populations apply the scientific method in their research.

Dr. Patrick Ressler, Chief Scientist

Dr. Patrick Ressler, Chief Scientist

To better understand how scientists “do science,” I had a conversation with Dr. Patrick Ressler, our Chief Scientist, about this topic. Dr. Ressler has been involved with the Pollock Acoustic Trawl Survey for many years and stresses that this ongoing research is a way to monitor change over time with pollock populations and to set quotas for commercial fisheries.  He shared his ideas about science and how it is a way to understand natural phenomena through testing. In biological research, however, it is harder to assess the outcomes because of the potential effects of outside factors.  That is why scientists refine their experiments to get “closer to the truth.”  Even being “wrong” about some ideas is beneficial because it facilitates opportunities to learn more. Scientists give testable ideas, or hypotheses, the chance to be wrong through repeated trials.

It was a circuitous path that Dr. Ressler took to become a scientist.  He studied environmental science and creative writing as an undergraduate, but after a semester abroad learning nautical science, he decided to study oceanography as a graduate student.  For his graduate studies, Dr. Ressler focused on acoustics and has worked on Pacific hake populations along the west coast of the U.S.  For the past 16 years, he has worked with NOAA as a Chief Scientist whose responsibilities include being a point of contact between the ship’s commanding officer and the management supervisor on land.  He has supported NOAA’s Teacher at Sea program because he feels that a good science teacher can better cultivate and inspire future scientists.

Screen with Acoustics Data

The screen displaying acoustics data is always monitored.

The  scientists on the Oscar Dyson have varied academic specialties, yet they are collaborating on the Pollock Acoustic Trawl Survey by contributing their expertise.  Dr. Ressler and Dr. Chris Bassett have been monitoring the acoustics on this expedition.  The acoustic system was most patiently explained to Joan and me by Dr. Bassett.

 

Dr. Chris Bassett

Dr. Chris Bassett, Ocean Acoustics Engineer

On the Oscar Dyson, there are 5 transducers producing vibrations on the drop keel of the boat.  Cables are attached that can lower this drop keel to 9.2 meters below so that storms will not interfere with the acoustics. These cables connect the drop keel to the five boxes in the survey room. Voltage signals are sent to the transceiver, which in turn creates a pressure wave.  When the signal is sent into the water, some sound bounces back. The pressure waves reflected back to the transducer are converted to an electrical signal and recorded by the computer. For the sound wave to scatter off something, it must have a density or sound speed different from that of the surrounding water. The larger the differences in the properties of the animals from the surrounding water, the more sound will generally be reflected by an animal. As a result, animals with ‘swim bladders’ (an organ inside their body containing air) will generally scatter more sound than animals without them.

When one of the transducers sends out a wave, the wave spreads out as it moves from the ship and it may encounter fish.  To assess the number of fish present, the total amount of acoustic energy, the volume of water, the range, and the echo expected from a single fish must be measured or estimated.

The acoustics translate into an ongoing screen display which is observed by both Dr. Ressler and Dr. Bassett in the acoustics lab.  The data displayed allows the scientists to decide whether a net sample is needed.

These scientists adhere to the scientific method so that they can make strong conclusions about their data. The acoustics portion is but one part of this ongoing research.  The trawls, after which we measure the length and mass of each fish, is a means of supporting the data from the acoustics portion. There are also cameras attached to the net so that the scientists can verify the type and abundances of fish species at each sampling transect. By corroborating findings in acoustics with the data from the trawls, these scientists can use their combined data to give greater insight on pollock populations and abundances.

Personal Reflection

I am in awe of people who do what they love for a career.  The scientists with whom I spoke convey their passion for their areas of expertise and are willing to share their knowledge.  These scientists have made me aware of outside resources so that I can learn more about the topic. Collaboration is evident among these scientists as each works to illuminate an aspect of the pollock population.  Together, their work sheds light on pollock dynamics.

Marine Careers

 Sandi Neidetcher, a research fishery biologist at the NOAA’s Alaska Fishery Wildlife Center

Sandi Neidetcher, a research fishery biologist at the NOAA’s Alaska Fishery Wildlife Center, holds a bag of pollock ovaries.

Scientists aboard the Oscar Dyson participate in the Pollock Acoustic Trawl Survey research as well as projects of their own.  Sandi Neidetcher, a research fishery biologist at the NOAA’s Alaska Fishery Wildlife Center, is investigating the reproductive biology of pollock and cod.  According to Sandi, the reproductive biology of pollock is important for assessing the stock. By carrying out data collection of pollock length and otolith analysis, scientists can determine whether 50% of the stock is mature.  For pollock, using the otolith analysis is a good indicator of age. Otoliths are made of calcium carbonate and are found in the fish’s inner ear and otoliths have annual growth rings, which allows for scientists to accurately assign their ages.  Since pollock is a commercial fish, it’s important to know how many of the fish are capable of reproducing and using this data, set quotas commercial fishing.   Another facet in researching pollock populations is determining where and when pollock spawn as well as the frequency of spawning.  Sandi has been studying pollock, in addition to other commercially caught species, for many years as a commercial fishery observer.  Currently, she is sampling pollock ovary tissue to determine fecundity, or fertility, of the population for stock assessment.

Sandi advises high school students who think they’d enjoy this type of career to get a college degree in biology.  She also encourages them to network and apply for internships.  Effusive when recounting her career in research, Sandi is equally enthusiastic discussing her horse and misunderstood dog.

Did you know?

Otoliths aid fish like pollock in balance and acceleration.

 

Something to think about….

What are some factors that might affect the growth of otoliths?

Brad Rhew: The Sounds of the Sea, July 31, 2017

NOAA Teacher at Sea

Brad Rhew

Aboard NOAA Ship Bell M. Shimada

July 23 – August 7, 2017

 

Mission: Hake Fish Survey

Geographic Area of Cruise: Northwest Pacific Ocean, off of the coast of Oregon

Date: July 31, 2017

 

Weather Data from the Bridge

Latitude: 44 49.160 N
Longitude 124 26.512

Temperature: 59oF
Sunny
No precipitation
Winds at 25.45 knots
Waves at 4-5ft

 

Science and Technology Log

TAS Rhew 7-31 acoustics lab2

Inside the acoustics lab

The scientists on the Hake survey project are constantly trying to find new methods to collect data on the fish. One method used is acoustics. Scientists Larry Hufnagle and Dezhang Chu are leading this project on the Shimada. They are using acoustics at a frequency of 38 kHz to detect Pacific Hake. Density differences between air in the swimbladder, fish tissue, and the surrounding water allows scientists to detect fish acoustically.

The purpose of the swim bladder in a fish is to help with the fish’s buoyancy. Fish can regulate the amount of gas in the swim bladder to help them stay at a certain depth in the ocean. This in return decreases the amount of energy they use swimming.

TAS Rhew 7-31 echosounder

The screen shows the data collected by the echosounder at different frequency levels.

Larry and Chu are looking at the acoustic returns (echoes) from 3 frequencies and determining which are Hake. When the echosounder receives echoes from fish, the data is collected and visually displayed. The scientists can see the intensity and patterns of the echosounder return and determine if Hake are present.

The scientists survey from sunrise to sunset looking at the intensity of the return and appearances of schools of fish to make the decisions if this is an area to fish.

TAS Rhew 7-31 scientists Larry and Chu

Scientists Larry Hufnagle (left) and Dezhang Chu (right) monitor the nets and echosounder while fishing for hake.

The ultimate goal is to use this data collected from the echosounder to determine the fish biomass. The biomass determined by the survey is used by stock assessment scientist and managers to manage the fish stock.

Personal Log

Everyday aboard the Shimada is a different experience. It has been amazing to be able to go between the different research labs to learn about how each group of scientists’ projects are contributing to our knowing more about Hake and marine ecosystems. My favorite part so far has been helping with the sampling of Hake. Some people might find dissecting fish after fish to determine length, sex, age, and maturity to be too much. However, this gives me an even better understanding and respect for what scientists do on a daily basis so we can have a better understanding of the world around us. We have also caught other fascinating organisms that has helped me explore other marine species and learn even more about their role in the ocean.

Even though the wind is a little strong and the temperatures are a little chilly for my southern body I wouldn’t trade this experience for anything…especially these amazing sunsets…

TAS Rhew 7-31 sunset

View of sunset over the Pacific Ocean from NOAA Ship Bell M. Shimada

Did You Know?

Before every fishing operation on the boat we must first do a marine mammal watch. Scientists and other crew members go up to the bridge of the boat to see if any mammals (whales, seals, dolphins) are present near the boat. This is to help prevent these animals from being harmed as we collect fish as well as making sure we are not running a risk of these mammals getting caught in the fishing nets.

Fascinating Catch of the Day!

Today’s fun catch in the net was a Brown Catshark! These creatures are normally found in the deeper parts of the Pacific Ocean. They are typically a darker brown color with their eyes on the side of their head. Their skin is very soft and flabby which can easily lead to them being harmed. They have two dorsal fins and their nostrils and mouth on the underside of their body. One of the sharks we caught was just recently pregnant.

 

TAS Rhew 7-31 catshark egg sack string

This catshark was recently pregnant; the yellow stringy substance is from an egg sack.

Notice to yellow curly substance coming out of the shark? That is from the egg sac. Sharks only produce one egg sac at a time. It normally takes up to a full year before a baby shark to form!

Staci DeSchryver: Things We Deliberately Throw Overboard Part Deux: The Ocean Noise Sensor July 20, 2017

NOAA Teacher At Sea

Staci DeSchryver

Aboard Oscar Elton Sette

July 6 – Aug 2

Mission:  HICEAS Cetacean Study

Geographic Area:  Northwest Hawaiian Island Chain, Just past Mokumanamana (Necker Island)

Date:  July 20, 2017

Weather Data from the Bridge:

Science and Technology Log:

As promised in Blog Post #3, I mentioned that “Thing number four we deliberately throw overboard” would have a dedicated blog post because it was so involved.  Well, grab some popcorn, because the time has arrived!

Thing number 4 we deliberately throw over the side of a ship does not get thrown overboard very often, but when it does, it causes much hubbub and hullaballoo on the ship.  I had the unique opportunity to witness one of only ten ocean noise sensors that are deployed in US waters come aboard the ship and get redeployed.  These sensors are found all over US waters – from Alaska to the Atlantic.  One is located in the Catalina Marine Sanctuary, and still others are hanging out in the Gulf of Mexico, and we are going to be sailing right past one!  To see more about the Ocean Noise Sensors, visit the HICEAS website “other projects” tab, or just click here.  To see where the Ocean Noise Recorders are, click here.

The Ocean Noise Sensor system is a group of 10 microphones placed in the “SOFAR” channel all over US waters.  Once deployed, they collect data for two years in order to track the level of ocean noise over time.  It’s no secret that our oceans are getting louder.  Shipping routes, oil and gas exploration, and even natural sources of noise like earthquakes all contribute to the underwater noise that our cetacean friends must chatter through.  Imagine sitting at far ends of the table at a dinner party with a friend you have not caught up with in a while.  While other guests chat away, you and the friend must raise your voices slightly to remain in contact.  As the night progresses on, plates start clanging, glasses are clinking, servers are asking questions, and music is playing in the background.  The frustration of trying to communicate over the din is tolerable, but not insurmountable.  Now imagine the host turning on the Super Bowl at full volume for entertainment.  Now the noise in the room is incorrigible, and you and your friend have lost all hope of even hearing a simple greeting, let alone have a conversation.  In fact, you can hardly get anyone’s attention to get them to pass you the potatoes.  This is similar to the noise levels in our world’s ocean.  As time goes on, more noise is being added to the system.  This could potentially interfere with multiple species and their communications abilities.  Calling out to find a mate, forage for food, or simply find a group to associate with must now be done in the equivalent din of a ticker-tape parade, complete with bands, floats, and fire engines blaring their horns.  This is what the Ocean Noise Sensor is hoping to get a handle on.   By placing sensors in the ocean to passively collect ambient noise, we can answer two important questions:  How have the noise levels changed over time?  To what extent are these changes in noise levels impacting marine life?   

Many smaller isolated studies have been done on ocean noise levels in the past, but a few years ago, scientists from Cornell partnered with NOAA and the Pacific Islands Fisheries Science Center (PIFSC) and the Pacific Marine Environmental Lab to streamline this study in order to get a unified, global data source of ocean noise levels.  The Pacific Marine Environmental Lab built a unified sound recording system for all groups involved in the study, and undertook the deployments of the hydrophones.  They also took on the task of processing the data once it is recovered.  The HICEAS team is in a timely and geographical position to assist in recovery of the data box and redeploying the hydrophone.   This was how we spent the day.

The recovery and re-deployment of the buoy started just before dawn, and ended just before dinner.

 Our standard effort of marine mammal observation was put on hold so that we could recover and re-deploy the hydrophone.  It was an exciting day for a few reasons – one, it was definitely a novel way to spend the day.  There was much to do on the part of the crew, and much to watch on the part of those who didn’t have the know-how to assist.  (This was the category I fell in to.)

At dawn, an underwater acoustic command was sent to the depths to release a buoy held underwater attached to the hydrophone.  While the hydrophone is only 1000m below the surface seated nice and squarely in the SOFAR channel, the entire system is anchored to the ocean floor at a depth of 4000m.  Once the buoy was released, crew members stationed themselves around the ship on the Big Eyes and with binoculars to watch for the buoy to surface.  It took approximately 45 minutes before the buoy was spotted just off our port side.  The sighting award goes to CDR Stephanie Koes, our fearless CO.  A crewmember pointed out the advancement in our technologies in the following way:  “We can use GPS to find a buried hydrophone in the middle of the ocean…and then send a signal…down 4000m…to a buoy anchored to the ocean floor…cut the buoy loose remotely, and then actually have the buoy come up to the surface near enough to the ship where we can find it.”  Pretty impressive if you think about it.

The buoy was tied to the line that is attached to the hydrophone, so once the buoy surfaced, “all” we had to do was send a fast rescue boat out to retrieve it, bring the buoy and line back to the ship, bring the crew safely back aboard the ship, hook the line up through a pulley overhead and back to a deck wench, pull the line through, take off the hydrophone, pull the rest of the line up, unspool the line on the wench to re-set the line, re-spool the winch, and then reverse the whole process.

Watching the crew work on this process was impressive at least, and a fully orchestrated symphony at best.  There were many tyings of knots and transfers of lines, and all crew members worked like the well-seasoned deck crew that they are.  Chief Bos’n Chris Kaanaana is no stranger to hauling in and maintaining buoys, so his deck crew were well prepared to take on this monumental task.

Much of the day went exactly according to plan.  The buoy was safely retrieved, the hydrophone brought on board, the lines pulled in, re-spooled, and all sent back out again.  But I am here to tell you that 4000m of line to haul in and pay back out takes. A Long. Time.  We worked through a rainstorm spooling the line off the winch to reset it, through the glare of the tropical sun and the gentle and steadfast breeze of the trade winds.  By dinner time, all was back in place, the buoy safely submerged deep in the ocean waters, waiting to be released again in another two years to repeat the process all over again.  With any luck, the noise levels in the ocean will have improved.  Many commercial vessels have committed to adopting “quiet ship” technology to assist in the reduction of noise levels.  If this continues to improve, our cetacean friends just might be able to hear one another again at dinner.

 

Personal Log

So, I guess it’s pretty fair to say that once you’re a teacher, you’re always a teacher.  I could not fully escape my August to May duties onboard, despite my best efforts.  This week, I found myself on the bridge, doing a science experiment with the Wardroom (These are what all of the officers onboard as a group are called).   How is this even happening, you ask?  (Trust me, I asked myself the same thing when I was in the middle of it, running around to different “lab groups” just like in class.)  Our CO, CDR Koes, is committed to ensuring that her crew is always learning on the ship.

 If her staff do not know the answer to a question, she will guide them through the process of seeking out the correct answer so that all  officers learn as much as they can when it comes to being underway –  steering the ship, preparing for emergencies, and working with engineers, scientists, and crew.  For example, I found out that while I was off “small-boating” near Pilot Whales, the Wardroom was busy working on maneuvering the ship in practice of man overboard scenarios.  She is committed to ensuring that all of her staff knows all parts of this moving city, or at a minimum know how to find the answers to any questions they may have.  It’s become clear just how much the crew and the entire ship have a deep respect and admiration for CDR Koes.  I knew she was going to be great when we were at training and word got out that she would be the CO of this Leg on Sette and everyone had a range of positive emotions from elated to relieved to ecstatic.

As part of this training, she gives regular “quizzes” to her staff each day – many of them in good fun with questions for scientists, crew, engineers, and I.  Some questions are nautical “things” that the Wardroom should know or are nice to know (for example, knowing the locations of Material Safety Data Sheets or calculating dew point temperatures), some questions are about the scientific work done onboard, while others are questions about personal lives of onboard members.

docandbromineDES_4437.JPG

The Chief Medical Officer, “Doc” gives a lesson on water quality testing.

 It has been a lot of fun watching the Wardroom and Crew seek out others and ask them where they live while showing them their “whale dance” to encourage sightings.  It has exponentially increased the interactions between everyone onboard in a positive and productive way.

The other teaching element that CDR Koes has implemented is a daily lesson each day from Monday to Friday just after lunch.  All NOAA Officers meet on the bridge, while one officer takes the lead to teach a quick, fifteen minute lesson on any topic of their choosing.  It could be to refresh scientific knowledge, general ship operations, nautical concepts, or anything else that would be considered “good to know.”

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The Chief Engineer gives a rundown on the various ship emergency alarms.

 This sharing of knowledge builds trust among the Wardroom because it honors each officer’s strong suits and reminds us that we all have something to contribute while onboard.

I started attending these lunchtime sessions and volunteered to take on a lesson.  So, this past Tuesday, I rounded up some supplies and did what I know best – we all participated in the Cloud in a Bottle Lesson!

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Here I am learning to use a sextant for navigation.

The Wardroom had fun (I think?) making bottle clouds, talking about the three conditions for cloud formation, and refreshing their memories on adiabatic heating and cooling.  It was a little nerve wracking for me as a teacher because two of the officers are meteorologists by trade, but I think I passed the bar.  (I hope I did!)

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Teaching about adiabatic cooling with the the Cloud in a Bottle Demo with the Wardroom!

It was fun to slide back into the role of teacher, if only for a brief while, and served as a reminder that I’m on my way back to work in a few weeks!  Thanks to the Wardroom  for calling on me to dust up my teacher skills for the upcoming first weeks of school!

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ENS Holland and ENS Frederick working hard making clouds.

 

 

 

 

 

 

 

 

 

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Facebook Asks, DeSchryver Answers

I polled all of my Facebook friends, fishing (ha ha, see what I did there?) for questions about the ship, and here are some of the questions and my answers!

 

Q:   LC asks, “What has been your most exciting moment on the ship?”

It’s hard to pick just one, so I’ll tell you the times I was held at a little tear:  a) Any sighting of a new species is a solid winner, especially the rare ones  b) The first time I heard Sperm Whales on the acoustic detector c) The first time we took the small boat out for UAS operations….annnndddd d) The first time I was on Independent Observation and we had a sighting!

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A group of Melon-Headed Whales, or PEPs, cruise along with the ship.

Q:  JK asks, “What are your thoughts on the breakoff of Larsen C?  And have there been any effects from the Alaskan quake and tsunami?”

We’re actually pretty isolated on board!  Limited internet makes it hard to hear of all the current events.  I had only briefly heard about Larsen C, and just that it broke, not anything else.  I had no clue there was a quake and tsunami!  But!  I will tell a cool sort of related story.  On Ford Island, right where Sette is docked, the parking lot is holding three pretty banged up boats.  If you look closely, they all have Japanese markings on them.  Turns out they washed up on Oahu after the Japan Tsunami.  They tracked down the owners, and they came out to confirm those boats were theirs, but left them with NOAA as a donation.  So?  There’s tsunami debris on Oahu and I saw it.

 

Q:  NG asks, “Any aha moments when it comes to being on the ocean?  And anything to bring back to Earth Science class?”

So many aha moments, but one in particular that comes to mind is just how difficult it is to spot cetaceans and how talented the marine mammal observers are! They can quite literally spot animals from miles away!  There are a lot of measures put in place to help the marine mammal observers, but at the end of the day, there are some species that are just tougher than nails to spot, or to spot and keep an eye on since their behaviors are all so different.  And as far as anything to bring back to our class?  Tons.  I got a cool trick to make a range finder using a pencil.  I think we should use it!

 

Q:  MJB asks, “Have you had some peaceful moments to process and just take it all in?”

Yes.  At night between the sonobuoy launches, I get two miles of transit time out on the back deck to just absorb the day and be thankful for the opportunities.  The area of Hawai’i we are in right now is considered sacred ground, so it’s very powerful to just be here and be here.

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These sunsets will give Colorado sunsets a run for their money.  No green flash in Colorado = point awarded to Hawai’i.

 

Q:  SC asks, “What souvenir are you bringing me?”

Well, we saw a glass fishing float, and we tried to catch it for you, but it got away.

Q:  LC asks, “What’s the most disgusting ocean creature?”

Boy that’s a loaded question because I guarantee if I name a creature, someone out there studies it for a living.  But! I will tell you the most delicious ocean creature.  That would be Ono.  In sashimi form.  Also, there is a bird called a Great Frigate bird – it feeds via something called Klepto-parasitism, which is exactly how it sounds.  It basically finds other birds, harasses them until they give up whatever they just caught or in some cases until it pukes, and then it steals their food.  So, yeah.  I’d say that’s pretty gross.  But everyone’s gotta eat, right?

Q:  KI asks, “Have you eaten all that ginger?”

I’m about two weeks in and I’m pretty sure I’ve eaten about a pound. I’m still working on it!

Q:  HC asks, ”Have you seen or heard any species outside of their normal ocean territory?”

Sort of.  Yesterday we saw Orca!  They are tropical Orca, so they are found in this area, but they aren’t very common.  The scientific team was thinking we’d maybe see one or two out of the entire seven legs of the trip, and we saw some yesterday!  (I can’t say how many, and you’ll find out why in an upcoming post.)  We have also seen a little bird that wasn’t really technically out of his territory, but the poor fella sure was a little far from home.

Q:  JPK asks, “What kinds of data have you accumulated to use in a cross-curricular experience for math?”

We can do abundance estimates with a reasonably simplified equation.  It’s pretty neat how we can take everything that we see from this study, and use those numbers to extrapolate how many of each species is estimated to be “out there.”

Q: AP asks, “What has surprised you about this trip?”

Many, many things, but I’ll mention a couple fun ones.  The ship has an enormous movie collection – even of movies that aren’t out on DVD yet because they get them ahead of time!  Also? The food on the ship is amazing.  We’re halfway through the trip and the lettuce is still green.  I have to find out the chef’s secret!  And the desserts are to die for.  It’s a wonder I haven’t put on twenty pounds.  The crew does a lot of little things to celebrate and keep morale up, like birthday parties, and music at dinner, and shave ice once a week.  Lots of people take turns barbecuing and cooking traditional foods and desserts special to them from home and they share with everyone.  They are always in really high spirits and don’t let morale drop to begin with, so it’s always fun.

DES_4454.JPG

Celebrating Engineer Jerry’s Birthday.

Q:  TS asks, “What’s the most exciting thing you’ve done?”

I’ve done lots of exciting things, but the one thing that comes to mind is launching on the small boat to go take photos of the pilot whales.  Such a cool experience, and I hope we get good enough weather to do it again while we’re out here!  Everything about ship life is brand new to me, so I like to help out as much as I can.  Any time someone says, “Will you help with this?” I get excited, because I  know I’m about to learn something new and also lend a hand. 

 

Staci DeSchryver: Listening with Your Eyes – How the Acoustics Team “Sees” in Sound, July 10, 2017

NOAA Teacher at Sea

Staci DeSchryver

Aboard NOAA Ship Oscar Elton Sette

July 6 – August 2, 2017

Mission:  HICEAS Cetacean Study

Geographic Area:  Kona Coast, Hawaii

Date:  July 10, 2017

Weather Data from the Bridge:

TAS DeScrhryver_weather data

Location and Weather Data

 

Science Log

While the visual team is working hard on the flying bridge, scanning the waters for our elusive cetacean friends, acoustics is down in the lab listening for any clues that there might be “something” out there.

TAS DeSchryver array

The hydrophone array is a long microphone pulled behind the ship

At any given time, two acousticians are listening to the sounds of the ocean via a hydrophone array. This array is a long microphone pulled behind the ship as she cuts through the water.  When the acousticians hear a click or a whistle, a special computer program localizes (or determines the distance to) the whistle or the click.

But it’s not quite as simple as that. There’s a lot of noise in the ocean.  The array will pick up other ship noise, cavitation (or bubbles from the propeller) on our ship, or anything it “thinks” might be a cetacean.  The acoustics team must determine which sounds are noise and which sounds belong to a mammal.  What the acousticians are looking for is something called a “click train.” These are sound produced by dolphins when they are foraging or socializing and are a good indicator of a nearby cetacean. On the computer screen, any ambient noise shows up as a plotted point on an on-screen graph.  When the plotted points show up in a fixed or predictable pattern, then it could be a nearby cetacean.

The acousticians are also listening to the sounds on headphones.  When they hear a whistle or a click, they can find the sound they’ve heard on the plotted graph.  On the graphical representation of the sounds coming in to the hydrophone, the x-axis of the graph is time, and the y-axis is a “bearing” angle.  It will tell which angle off the ship from the front the noise is coming from.  For example, if the animal is right in front of the bow of the ship, the reading would be 0 degrees.  If it were directly behind the ship, then the plotted point would come in at 180 degrees.  With these two pieces of information, acousticians can narrow the location of the animal in question down to two spots on either side of the ship.  When they think they have a significant sound, the acousticians will use the information from the graph to localize the sound and plot it on a map.  Often times they can identify the sound directly to the species, which is an extraordinary skill.

Here’s where things go a little “Fight Club.”  (First rule of fight club?  Don’t talk about fight club.)  Once the acousticians localize an animal, they must determine if it is ahead of the ship or behind it.   Let’s say for example an acoustician hears a Pilot Whale.  He or she will draw a line on a computerized map to determine the distance the whale is to the ship using the data from the graph.

DeSchryver HICEAS-AC20

This is a “clean” localization of a marine mammal. Notice the two spots where the lines cross – those are the two possible locations of the mammal we are tracking. The ship is the red dot, the blue dots are the hydrophone as it is towed behind the ship.

Because the hydrophones are in a line, the location provided from the array shows on the left and the right sides.  So, the map plots both of those potential spots.  The two straight lines from the ship to the animal make a “V” shape.  As the ship passes the animal, the angle of the V opens up until it becomes a straight line, much like opening a book to lay it flat on the table and viewing how the pages change from the side.  As long as the animal or animal group is ahead of the ship, the acousticians will alert no one except the lead scientist, and especially not the marine observers.  If a crew member or another scientist who is not observing mammals just so happens to be in the acoustics lab when the localization happens, we are sworn to secrecy, as well.  Sometimes an acoustician will send a runner to get the lead scientist to discreetly tell her that there is something out there.

TAS DeSchryver HICEAS-AC25

The screenshot on the left shows a series of spotted dolphin “click trains.” Notice the marks all in a line along the graph. The right photo shows the various localizations that the acoustics team has picked up from the click train graph. The red dot is the ship, the gray line is the “track line”, and the two blue dots behind the ship are the hydrophone arrays. Notice the V shape gradually goes to a straight line and then turns in the opposite direction.

 

This way, the lead scientist can begin the planning stages for a chase on the mammals to do a biopsy, or send the UAS out to get photos with the Hexacopter.  (More on this later.)

As the mammals “pass the beam” (the signal is perfectly on either side of the ship, and starting to make an upside down V from the ship), the acousticians can alert the visual team of the sighting.  As soon as everyone is aware the mammals are out there, either by sight or sound, the whole scientific group goes “off effort,” meaning we funnel our energy in to counting and sighting the mammals we have found.  When this happens, communication is “open” between the acoustics team and the visual team.  The visual team can direct the bridge to head in any direction, and as long as it’s safe to do so, the bridge will aid in the pursuit of the mammals to put us in the best position to get close enough to hopefully identify the species.  Today, one mammal observer had a sighting almost 6 miles away from the ship, and she could identify the species from that distance, as well!  Even cooler is that it was a beaked whale, which is an elusive whale that isn’t often sighted.   They have the capability of diving to 1000m to forage for food!

When the visual team has a sighting, the three visual observers who are on shift have the responsibility to estimate the group size.

TAS DeSchryver chris takes photos

Chris captures photos of Melon Headed Whales for Photo ID.

 

Here we go with Fight Club again – no one can talk to one another about the group sizes.  Each mammal observer keeps their totals to themselves.  This is so that no one can sway any other person’s opinion on group size and adds an extra element of control to the study.  It is off limits to talk about group sizes among one another even after the sighting is over. We must always be vigilant of not reviewing counts with one another, even after the day is done.  The scientific team really holds solid to this protocol.

Once the sighting is over, all parties resume “on effort” sightings, and the whole process starts all over again.

Now, you might be thinking, “Why don’t they just wait until acoustics has an animal localized before sending the mammal team up to look for it?

TAS DeSchryver ernesto big eyes

Ernesto on the “Big Eyes” during a Melon Headed Whale Visual Chase

Surely if acoustics isn’t hearing anything, then there must not be anything out there.”  As I am writing this post, the visual team is closing in on a spotted dolphin sighting about 6.5 miles away.  The acoustics did not pick up any vocalizations from this group.

TAS DeSchryver acoustics lab 2

Shannon and Jen in the acoustics lab “seeing” the sounds of the ocean.

This also happened this morning with the beaked whale.  Both teams really do need one another in this process of documenting cetaceans.  Further, the acoustics team in some cases can’t determine group sizes from the vocals alone.  They need the visual team to do that.  Each group relies on and complements one another with their own talents and abilities to conduct a completely comprehensive search.  When adding in the hexacopter drone to do aerial photography, we now have three components working in tandem – a group that uses their eyes to see the surface, a group that uses the ocean to “see” the sounds, and a group that uses the air to capture identifying photographs.  It truly is an interconnected effort.

 

Personal Log

I haven’t gotten the chance to discuss just how beautiful Hawai’i is.  I would think that it is generally understood that Hawai’i is beautiful – it’s a famed tourist destination in an exotic corner of the Pacific Ocean. But you have to see it to believe it.

TAS DeSchryver melon-headed whales

Melon-Headed Whales take an evening ride alongside the starboard side of Sette.

I’ve been lucky enough to see the islands from a unique perspective as an observer from the outside looking inland, and I just can’t let the beauty of this place pass without mention and homage to its stunning features.

Hawai’i truly is her own artist.  Her geologic features create the rain that builds her famed rainbows, which in turn gives her the full color palate she uses to create her own landscape.  The ocean surrounding the shores of Hawai’i are not just blue – they are cerulean with notes of turquoise, royal, and sage.  She will not forget to add her contrasting crimson and scarlet in the hibiscus and bromeliads that dot the landscape. At night when the moon shines on the waters, the ocean turns to gunmetal and ink, with wide swaths of brass and silver tracing the way back up to the moon that lights our path to the sea.  With time, all of her colors come out to dance along the landscape – including the sharp titanium white foam that crashes against the black cliffs along Kona.  And if a hue is errantly missed in her construction of the landscape, early morning showers sprout wide rainbows as a sign of good fortune, and as a reminder that she forgets no tones of color as she creates.

It is our responsibility to protect these waters, this landscape – this perfect artistry.  It is critically important to protect the animals that live in the ocean’s depths and the ones that cling to the island surface in their own corner of paradise.  I like to think that this study takes on this exact work.  By giving each of these species a name and identifying them to each individual group, we share with the world that these cetaceans are a family of their own with a habitat and a purpose.  When we “re-sight” whales that the team has seen in past studies, we further solidify that those animals have families and a home amongst themselves.   The photo identification team counts every new scar, marking, and change in these animals to piece together the story of their lives since they last met with the scientists.  Everyone on Oscar Elton Sette  talks about the new calves as if we were at the hospital with them on the day of their birth, celebrating the new life they’ve brought forth to continue their generations.  I like to think we all make a little room in the corner of our hearts for them as a part of our family, as well.

Did you know?

The Frigate bird has a Hawaiian name, “Iwa”, which means “thief.”  They call this bird “thief” because they steal prey right from the mouths of other birds!

 

“Spyhopping” is the act of a whale poking his head out of the water and bobbing along the surface.

 

It is legal for research ships to fish off the ship, so long as we eat what we catch while underway.  This led to the shared consumption of some delicious mahi mahi, fresh from the depths for lunch today.  Yes.  It was as good as it sounds.

 

Oscar Elton Sette knows how to celebrate!  Yesterday was Adam’s birthday, a marine mammal observer.  They decorated the mess in birthday theme, cranked up the dinnertime music, and the stewards made Adam his favorite – blueberry cheesecake for dessert!

 

Much of the crew likes to pitch in with food preparation.  The on ship doctor, “Doc”, makes authentic eastern dishes, and the crew made barbeque for everyone a few nights ago at dinner.

Dawn White: Pinging for Populations, June 29, 2017

 

NOAA Teacher at Sea

 Dawn White

Aboard NOAA Ship the Reuben Lasker

June 19 – July 1, 2017

 

Mission: West Coast Sardine Survey

Geographic Area of Cruise: Pacific Ocean; U.S. West Coast

Date: June 29, 2017

 

Weather Data from the Bridge

Date: June 29, 2017                                                         Wind Speed: 7.7 kts

Time: 6:15 p.m.                                                                 Latitude: 4805.5N

Temperature: 12.7oC                                                      Longitude: 12520.07W

 

Science and Technology Log

The technology present on this ship is amazing and at the same time quite overwhelming.  These systems allow for data to be collected on a wide range of variables both continuously and simultaneously.  Below are a couple of photos of the acoustics room where multiple sensors are monitoring the feedback from sonar systems placed below the ship’s hull.  One of the acoustic probes sends out sound waves in a cone-like formation directly below the ship.  Another unit emits sound waves in a horizontal pattern.  The ship was designed to run as quietly as possible so as to not disturb the marine life present in the waters as the ship passes by and also to reduce the interference of the ship’s sounds with the acoustics feedback.

 

 

Acoustics technician Dan Palance managing the multiple computers that are constantly collecting data.

Multiple programs help to eliminate the “noise” received by the probes until all that remains are images that represent schools of fish and their location relative to the ocean floor.

 

The images above were taken from a poster on board the Reuben Lasker. They illustrate the range of the water column surveyed by the various acoustic systems.

 

The “soundings” are received by the ship, processed and “cleaned up” using a series of program algorithms. The image below shows the feedback received from one of the systems.

Displays of feedback from an acoustics system

Once the background “noise” has been eliminated, the resulting image will show locations of fish, school size, and the depth (y axis) at which they can be found.

Graph of acoustic feedback, with background “noise” eliminated, depicting depth and size of fish schools

 

Extension question for my students reading this:  Approximately how deep are the schools of fish being picked up by the sonar at this location?

Acoustics aren’t the only tools used to try pinpoint the locations of the fish schools.  As I wrote about on an earlier blog, the CUFES egg sampler is used to monitor the presence of fish eggs in the waters that the ship passes over.  Water samples are analyzed every half hour.  If egg samples appear in an area where there is also a strong acoustics signal, then that may be a location the ship will return to for the night’s trawl.  The main focus of this trip is to monitor the anchovy and sardine populations, so extra attention is paid to the locations where those eggs appear in the samples.

Personal Log:

Each time we drop the net for an evening trawl it is always retrieved with a bit of suspense:  What’s going to be in the net this time?  How big is the haul?  Will we capture any of the key species or haul in something completely different?

I can honestly say that while on board there were no two hauls exactly the same.  We continued to capture large quantities of pyrosomes – unbelievable amounts.  Check out the net-tearing load we encountered one night.  We literally had to weigh them by the basketful!

Here I am getting ready to help unload this large catch.

TAS Dawn White prepares to help unload large catch

 

Net-tearing load of pyrosomes!

Above is the codend of the net filled with pyrosomes and fish.  A 5-basket sample was pulled aside for analysis.  The remainder was simply classified and massed.

While I was certainly don’t need to see another pyrosome any time soon, there were plenty of other times when some very unique species made an appearance!

Pacific Jack Mackerel

Solitary Common Salp

TAS Dawn White holds a Blue Shark

Dogfish Shark

Did you know?

The dogfish shark (pictured above) was one of about 50 or so that were caught in the same haul.  We had trawled through a school that was feeding on the small fish found at the ocean surface during the evening hours.  This is the same species of shark that is commonly provided to students for dissection.  Use the search terms “dogfish shark dissection” and see what you find!

Nikki Durkan: The sound of…fishes! June 17, 2015

NOAA Teacher at Sea
Nikki Durkan
Aboard NOAA Ship Oscar Dyson
June 11 – 30, 2015

Mission: Midwater Assessment Conservation Survey
Geographical area of cruise: Gulf of Alaska
Date: Wednesday, June 17, 2015

Weather Data from the Bridge:
Wind speed (knots):  13.47
Sea Temp (deg C):  8.55
Air Temp (deg C):  9

Science and Technology Log

The sound of fishes.

What are we doing here off the coast of the Aleutian Islands? Listening…sort of.  We are collecting data used to estimate biomass (total amount of living matter in a given habitat) and to project population estimates for the Walleye Pollock Gadus chalcogrammus fishery.

Transects we fish are the lines somewhat perpendicular to the islands.

Transects we fish are perpendicular to the islands.

How do we do this? In order to understand the instruments we are utilizing, I’ll attempt a simple but not completely accurate analogy: if I bounce a basketball on a cement driveway – it could bounce back with enough energy to hit me in the face (I’m not saying this has happened to me); however, if instead, I bounce the ball down onto a grassy lawn, the ball will barely bounce back up.   Different materials reflect energy back with different frequencies and the picture this information translates to on a computer monitor is called an echogram:

Red - seafloor Bluish dots above - fishes!

Red – seafloor
Bluish dots above – fishes!

The Oscar Dyson has several scientific echosounders (EK60, EK80, and ME70) with transducers attached to our hull that send out energy at various frequencies. As we travel along the transects (mostly perpendicular to the island chain) we are collecting these acoustic data. The fish species produce a different pattern on the echogram and the swimbladder (full of air) makes them show up clearly; scientists have been studying the Walleye Pollock for a while now and have a pretty good idea of what Walleye Pollock “look” like on an echogram.  Sometimes the scientists observe an echogram that they are not certain about or want to verify characteristics such as length, weight, and age for an area – this means we get to fish!

 

Me learning to measure the length of a Pollock.  Photo Credit:  Patrick Ressler

Me learning to measure the length of a ~3 yr Pollock. Photo Credit: Patrick Ressler

Personal Log

The process began with a bit of dancing to Macklemore and Gangnam Style (thanks, Alyssa Pourmonir for providing the playlist!).  Music makes every task more enjoyable! I learned how to sex a fish and cut its skull open to pull out the otoliths (calcium carbonate structures located behind the brain that can be used to estimate age and growth rate) – more on this process to come! Given that I spent the majority of my childhood as a vegetarian and maintained aspirations of becoming a veterinarian and saving the lives of animals, today was a gigantic step in another direction. I could not help but feel remorse as I sliced into the bellies of the fish and splayed them open to reveal the ovaries or testis.  As a newbie, I was quite a bit slower than my coworkers, but after about 30 fish, I started to hesitate less often and verify the gonads more quickly. If any of you have spent time fishing with me, you’ll know that I enjoy the chase, but avoid handling the fish once they are on board, I’ve even been known to utter an impulsive “uh oh” when I catch a fish. I am pretty sure that after this trip, I’ll be comfortable filleting…no guarantees on my casting skills.

We unintentionally caught a salmon shark but the crew was able to return it safely!

We unintentionally caught a salmon shark but the crew was able to return it to the ocean safely!

Did you know?  Killer whales are the most widely distributed marine mammal and live in matriarchal societies.  I’ve been enjoying watching these whales from the bridge!