Lacee Sherman: Teacher Counting Krill June 16, 2018

NOAA Teacher at Sea

Lacee Sherman

Aboard NOAA Ship Oscar Dyson

June 6, 2018 – June 28, 2018

Mission: Eastern Bering Sea Pollock Acoustic Trawl Survey

Geographic Area of Cruise: Eastern Bering Sea

Date:  June 16, 2018

 

Scientists on deck

Fisheries Biologist Sarah Stienessen, Chief Scientist Denise McKelvey, TAS Lacee Sherman, and Fisheries Biologist Nate Lauffenburger on the Hero Deck of NOAA Ship Oscar Dyson in front of a few volcanoes.

 

Weather Data from the Bridge at 18:30 on 6/17/18:

Latitude: 57° 09.7 N

Longitude: 166° 26.4 W

Sea Wave Height: 3-5 ft

Wind Speed: 10 knots

Wind Direction: 345°

Visibility: 8 knots

Air Temperature: 7.2° C

Water Temperature: 7.8° C

Barometric Pressure:  996.8 mb

Sky:  Grey and slightly foggy

More scientists on deck

TAS Lacee Sherman with Fisheries Biologists Matthew Philips and Nate Lauffenburger on deck of NOAA Ship Oscar Dyson in front of nearby Volcanoes

Science and Technology Log

In the fish lab, after the haul is sorted out, a sample of each species are randomly selected to undergo additional measurements and data collection.  One of the primary pieces of information needed is the lengths for about 300 pollock per haul.  The length of the pollock is important because larger fish have larger internal organs.  The internal organ that matters most to this survey is the size of the swim bladder since this is what give us the echo that can be picked up by our acoustic transducers.

According to the NOAA Ocean Service, “If fish relied solely on constant swimming to maintain their current water depth, they would waste a lot of energy. Many fish instead rely on their swim bladder, a dorsally located gas-filled organ, to control their stability and buoyancy in the water column. The swim bladder also functions as a resonating chamber that can produce and receive sound, a quality that comes in handy for scientists locating fish with sonar technology.”

To process a trawl sample, the pollock are put into baskets and weighed. One basket is selected at random to obtain the lengths and weights of individual fish. 30-35 Fish are selected for otolith samples (ear bones) that can be used to age the fish.  These fish are also inspected to look for the sex of the fish and their maturity stages.  There are 5 different maturity stages for pollock:  immature, developing, pre-spawning, spawning, and spent.  Since the fish already needs to be cut open for this process, we will sometimes look at the stomach contents of the fish as well to see what they are eating.  Based off of stomach contents, one of the main food sources for pollock in the Bering Sea this summer are euphausiids, or krill.

Flow meter

Flow Meter used on the Methot Net. This is a calibrated instrument and we use the number of spins to measure the volume of water going through the net. This is an important tool for determining the catch per unit effort.

In addition to trawl samples, we also are taking samples of Euphausiids with a special tool called a Methot net. Four Methot samples will be taken on each leg of this research survey.  A Methot net includes a sturdy metal frame of a set circumference with a net attached to the back. The net is a very fine mesh (small holes), so that the small euphausiids don’t escape.  A flow meter is attached that measures the volume of water that is going through the net.

Methot Net on deck

A photo of the methot net on deck of the NOAA Ship Oscar Dyson

The euphausiids are a very important component of the marine food web in the Bering Sea.  Euphausiids eat very small phytoplankton and zooplankton, so they are omnivores.  Pollock eat the euphausiids, and then the pollock are eaten by marine animals such as seals, orcas, large cod, and even larger pollock.  Humans also eat pollock, often in the form of imitation crab meat and the fish filet sandwiches from fast food chains.

Euphausiids being counted

Euphausiids being separated into groups of 10 so that they can be counted. This only represents a small sample of what was brought in with the Methot. There were 1,110 in total counted.

Once the Methot net has come back on the ship at the end of the haul, a scoop (sub-sample) of them is taken and counted.  Fish larvae and anything else that is not euphausiids is taken out and counted separately and then we go to work counting to get a total number of euphausiids from our sample.  In our small sub-sample of .052 kg, our count was 1,110 euphausiids.  Based off of the total haul weight of 2.12 kg, we are able to estimate the total number of euphausiids for this haul to be 45,251.  This number is calculated based off the total number and weight of our sub-sample, compared to the total weight of the Methot haul.

Personal Log

I finally saw Orcas!!  All of the running around on the ship was worth it!  We always seem to be heading in opposite directions so I have seen mostly just dorsal fins, but I’ll take it!  One morning I finally saw them from a closer distance and was able to see the white patch near the eye.  I feel like I will be remembered by everyone on the ship as the “crazy whale-obsessed teacher,” but I can live with that.

First Orca

The dorsal fin of an Orca spotted from NOAA Ship Oscar Dyson

One of the side experiments happening on the ship looks at the survival rate of fish caught on traditional fishing lines versus fish caught in trawl nets.  One pollock had been caught and all of us on the ship decided the name should be Jackson Pollock.  Jackson survived for a few days, but didn’t last past 6/15/18.  The next day six new fish were put into the tank after a trawl catch, and after 24 hours, only two were still alive.

 

NOAA Careers and Unexpected Learning Opportunities

I have been trying to talk to everyone on the ship about how they first got interested in this type of work and exactly what their role is for day to day operations.  There are so many different career options that can allow you to live on ships and be involved with scientific research.

The past few days I have spent time trying to learn as much as I can about everything related to the ship.  I spent time speaking with Commanding Officer (CO) Michael Levine and Ensign (ENS) Sony Vang about their ship and land assignments and the requirements of the NOAA Corps.  ENS Vanessa Oquendo showed me how some of the ship’s controls work.  They are regularly focused on navigation (on a paper chart and electronically), and communication with other ships about positioning, weather, and the speed and direction of the ship.  There is a lot to consider and to maintain 24/7.

Easy button and emergency affirmation

A few of my favorite buttons on the ship.

Getting the nets in and out of the water is a very complicated process and involves many different ropes, chains and weights.  I noticed this really cool type of knot that seemed to undo itself, so I asked one of the Deck Crew members, Jay Michelsen to teach me some cool ship knots.  I learned how to make:  bowline knots, flying bowline knots, cow hitch knots, daisy chains, double daisy chains, and a way to finally wrap up headphones so that they won’t tangle themselves.

Matthew Phillips and Scientist Mike Levine taught me how to fillet a fish which will be useful since I enjoy cooking so much! I will no longer be intimidated to buy fish whole.  We got some practice on a spare cod that we caught and a few rockfish.

One of the licensed engineers, Becca Joubert, gave me a tour of the engine room and I was able to see the engines, winches, rudder, water filtration systems, and the repair shop.  I didn’t realize that fuel was held in different tanks, but it works best that way because of safety and because it helps to distribute the weight all around the ship better.

 

 

Did You Know?

The NOAA Ship Oscar Dyson was named after a commercial fisherman named Oscar Dyson.   There is a smaller boat on board named the Peggy Dyson after his wife, who would broadcast the weather forecast twice a day every day to local ships as well as personal announcements and important sports scores.

Things to Think About:

Dolphins and Orcas eat a variety of fish, squid, and sometimes other marine mammals, while large whales such as blue whales and humpbacks mostly rely on krill as their main food source. Why would such large marine mammals feed primarily on tiny krill?

Since there is a relationship between pollock and euphausiids, as the number of pollock grows, what is a reasonable prediction about the number of euphausiids?

 

 

Marsha Lenz: Celebrating Science and the Solstice, June 21, 2017

NOAA Teacher at Sea

Marsha Lenz

Aboard Oscar Dyson

June 8-28, 2017

Mission: MACE Pollock Survey

Geographic Area of Cruise: Gulf of Alaska

Date: June 21, 2017

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Though modern technology is used daily, one can still find traditional charting tools on the Bridge.

Weather Data from the Bridge

Latitude: 55 15.0 N

Longitude: 160 06.7 W

Time: 1300

Visibility: 10 Nautical Miles

Wind Direction: VAR

Wind Speed: LT

Sea Wave Height: <1 foot

Barometric Pressure: 1003.4 Millibars

Sea Water Temperature: 9.8°C

Air Temperature: 7.0°C

Science and Technology Log

            We have been surveying transect lines (sometimes we fish, sometimes we don’t). During the times that we aren’t fishing, I find myself looking out at the ocean A LOT! During these quiet times on the ship, I am reminded of how large the oceans are. I found a quiet window to sit by in the Chem Lab and enjoy watching as the waves dance off of the side of the ship.

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Abigail enjoys singing to the fish.

During some of these times when we are not collecting data from fish, identifying species from the DropCam, or preparing for the next haul, I find myself reading, which is a luxury all in itself. A friend of mine lent me to book to read and as I was reading the other day, the author quoted Jules Verne, author of 20,000 Leagues Under the Sea. Verne said, “Science, my lad, is made up of mistakes, but they are mistakes which it is useful to make, because they lead little by little to the truth.” I found this to be fitting for what I am doing on this survey, for the three weeks that I am a Teacher At Sea.   Though I am surrounded by trained and educated professionals, I have realized that mistakes still happen and are something to be expected.   They happen regularly. Often, actually. And, it’s a good thing that they do. They are important for learning. When humans make mistakes, hopefully, we can adjust our actions/behaviors to reduce the chances of that same “mistake” from happening again. When applied to science, the same idea is also true. When  we can collect data from something that we are studying, we learn about the ways that it interacts with its surroundings. Through these findings, we not only learn more about what we are studying, but then take measures to protect its survival.

We had a real experience like this happen just the other day. For days, the “backscatter” was picking up images of fish that the scientists didn’t think were pollock on the bottom of the ocean. Backscatter is what the scientists use to “see” different groups of fish and quantify how many are in the water. The ship uses various echosounders.  Several times, the science team decided to collect fish samples from these areas.  Every time that they decided to “go fishing”, we pulled up pollock. The team was baffled. They had a hypothesis as to why they were not catching what they thought they saw on the backscatter. They thought that it was rockfish that were hanging around rocks, but the pollock were being caught as the net went down and came back up.  Finally, after several attempts of not catching anything but pollock, they decided to put down the DropCam and actually try to see what was going on down there.

At that point, the Chem lab was filled with scientists. Everyone wanted to see what was going to show up on the monitor. The NOAA Corps Commanding Officer even came to see what was going to show up on the monitor.  The room will filled with excitement.

 

Abigail steers the DropCam and watches the monitor simultaneously.

We see rockfish!

          It was just as they predicted!  The rockfish were hanging out in the rocks.  It was a moment of great satisfaction for the scientists. They were able to identify some of the fish on the backscatter that was causing them so much confusion! Yay, science!

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This is a pollock!

Later in the day, we went fishing and collected the usual data (sex, length, weight, etc.) from the pollock.  There are usually 4 of us at a time in the Fish lab.  We are getting into a routine in the lab and I am getting more familiar with my responsibilities and duties. I start by controlling the door release, which controls the amount of fish released onto the conveyor belt. After all of the fish have been weighed, I separate the females and males.  Once that has been done, I take the lengths of a sample of the fish that we caught. When I finish, I assist Ethan and Abigail in removing and  collecting the otoliths from a selected fish sample.  Then, its clean-up time.  Though we all have appropriate gear on, I somehow still end up having fish scales all over me.  Imagine that!

Every time that we “go fishing”, a “pocket net” is also deployed.  This is a net that has finer mesh and is designed to catch much smaller marine life.  On this haul, we caught squid, age “zero” pollock, and isopods.

In the evening, we headed towards Morzhovoi Bay.  There, we were greeted by a pod of Pacific white-sided dolphins.  They spent some time swimming next to us.  When they discovered that we were not that interesting, they swam off.  They did leave us though with a great sense of awe and appreciation (and a few great pictures!).

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Personal Log

Happy Summer Solstice!  Today is the longest day of the year!  We have had some spectacular days. We were all excited as we got up this morning to welcome the rising of the sun. We woke up and were holding position in front of Mt. Pavlof.  We saw the sunrise and went up to the  Flying Bridge to do some morning yoga.  After a wonderful breakfast of a bagel with cream cheese, salmon, Larrupin sauce, and Slug Slime, I went back up to the Bridge to get a full 360 degree view of the bay.  There I saw a humpback whale swimming around.  This will definitely be a summer solstice to remember!

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Did You Know?

A humpback whale is about the size of a school bus and weighs about 40 tons! They also communicate with each other with songs under the water.

sidenote: I know I wrote in my last blog that I was going to discuss the fishing process today, but there were so many other amazing things that happened that it is going to have to wait until next time. Sorry!

 

Mary Patterson, June 17-19, 2009

NOAA Teacher at Sea
Mary Patterson
Onboard NOAA Vessel Rainier 
June 15 – July 2, 2009 

Mission: Hydrographic Survey
Geographical area of cruise: Pavlov Islands, AK
Date: June 17-19, 2009

Weather Data from the Bridge 
Overcast
Wind 15 kts
8 mi visibility
Pressure 999.5 mb
Dry Bulb Temp 6.7 C Wet bulb 5.6 C
Seas 0-1 ft.
Water temp 6.7C, 44 F

Here I am getting ready to cast the CTD.

Here I am getting ready to cast the CTD.

Science and Technology Log 

While the weather holds, we head out on the launches to survey areas that are not charted or were last charted probably back in the time of Captain Cook. After the boats are lowered using gravity davits, 4 boats head out to survey. Upon reaching the survey area, the first thing that gets done is a casting. This consists of lowering the CTD (Conductivity, Temperature and Depth) unit into the water at the surface for 2 minutes for calibration. Then it’s lowered to the sea floor (taking measurements as it goes) and brought back up to the surface with a winch and a pulley system. The sensor unit is cabled to the computer and the data is downloaded. This is a vital step in interpreting the sonar data. Since saltwater conducts electricity differently based on the salt concentration, using the CTD gives the hydrographer information about sound velocity at different depths.

Velocity of sound is most affected by temperature, which is also measure by the CTD.  Next, the hydrographer decides whether to use the high or low frequency transmitter depending on the depth. The hydrographer uses a lower frequency for deeper water.  Casting is often done again after lunch since temperatures can change, especially at the surface. Alaska is known for the confluence of fresh and salt water at the surface due to melting glaciers and fresh water runoff. The MVP (moving vessel profile), is another device used for sound velocity. It looks like a torpedo and it’s towed behind the boat allowing for continuous casting.

The shape of a plane has more points than a boat so is a good way to use points to line up a survey transect.

The shape of a plane has more points than a boat so is a good way to use points to line up a survey transect.

The plane you see on the picture is used instead of a boat because of the position of the GPS sensor relative to the shape. The coxswain can make the plane pivot on a point as they line up on a line to survey. On the survey, the map is broken down into polygons. Each sheet manager gets a sheet with their polygons to survey. Surveying consists of the coxswain driving the boat as they watch the computer screen. As they drive, the screen shows in real-time a swath of color indicating the swath of the beams. After surveying, the boats return to the ship and are hoisted back up onto the davits. All survey techs meet in the wardroom to discuss what happened on their survey. The Captain and FOO (Field Operation Officer) ask questions about what was surveyed and any problems they had with any equipment. This is a true community of scientists who share data and knowledge.

Worksheet with polygons completed

Worksheet with polygons completed

Personal Log 

We load the launches at 8:00 am and complete surveys until noon.  We break for lunch and unpack the ice chest packed by the cooks for us. It’s always a surprise to see what we have! Then we continue surveying until about 4:00 pm when we return back to the ship. I have had the opportunity to cast the CTD unit into the water, drive the launch and collect the data on the computers. The coxswains make driving the boat following the lines on the computer look so easy! Especially in rough seas, the coxswains do an amazing job of helping the survey techs collect data. Again, good communication is a key! I’ve also seen how the techs have to problem- solve on a daily basis.

One day we got into the launch and the engine wouldn’t start and the coxswain had to troubleshoot the problem. Another day, several boats had problems with their CTD units and they had to repeat trials several times. When you are 12 miles away from the nearest help, it’s crucial to have good problem-solving skills. After dinner, there’s time to finish writing journals, do laundry, fish off the fantail, watch a movie, play guitar hero or exercise in the gym area. Then, it’s time for bed and the day will start over again. If you are not on a survey launch, you work in the night processing lab compiling the data collected by the survey techs during the day’s launch. This includes applying various filters to clean up the “noise” or fuzziness from the sonar. The coolest part is seeing the data in three dimensions. After the data is cleaned up, the sheet managers write up a descriptive report that gets sent to Pacific Hydrographic Branch. This ship is a great example of a system: there are many separate parts that when combined with other parts, complete a task. 

Pavolf and Pavlof’s Sister are active volcanoes.

Pavolf and Pavlof’s Sister are active volcanoes.

Each night at 10 pm, fellow Teacher at Sea –Jill Stephens and I go to the bridge and collect weather data that is transmitted directly to NOAA. Although the days have started off hazy and grey, by evening we often see sunshine that lasts until 11:00 pm. This part of Alaska is breathtaking! I love watching the volcanoes, Pavlov and Pavlov’s sister, in different types of light.

Animals Seen 

Whales, Puffins, and Sea gulls.

New Word of the Day 

Cavitation: The sudden formation and collapse of low-pressure bubbles in liquids by means of mechanical forces, such as those resulting from rotation of a marine propeller. 

Lisa Hjelm, August 12, 2008

NOAA Teacher at Sea
Lisa Hjelm
Onboard NOAA Ship Rainier
July 28 – 15, 2008

Mission: Hydrographic Survey
Geographical area of cruise: Pavlov Islands, Alaska
Date: August 12, 2008

Chief Boatswain outlining the day’s work to crewmember

Chief Boatswain outlining the day’s work to crewmember

Science and Technology Log 6: Looking Ahead 

The weather started getting rough, the tiny ships were tossed. If not for the courage of the fearless crews the data could be lost. 

We’re into our last two work days before Rainier begins the transit back to Homer, AK. The weather has indeed changed. The skies are shifting, shades of gray, and this afternoon the winds may kick up to 15 knots. Spits of rain hit your face when you venture on deck. It could be a rough day on the launches. A few people picked up seasickness medication on the way to the morning meeting on the fantail. After fifteen days of work the faces of the crew of the Rainier are taking on determined, tired looks.  These are the final days of the 2008 season in the Pavlof Island area.

Even with an end in sight no one is gearing down. There is still plenty to do. The crew is preparing the ship for an upcoming inspection and an open house during “Hydrapalooza”, a gathering of hydrographers in Homer, AK. The officers are preparing for the 36-hour return transit. The survey technicians are putting finishing touches on their final survey sheets and reports for this area. There is activity and some excitement everywhere. Perhaps due to the extended period of fine weather, work is ahead of schedule. Today, the launches are surveying a new sheet that wasn’t scheduled until 2009. They’ve named this one SNOW: white uncharted territory.

Okeanos Explorer, image courtesy of NOAA Office of Ocean Exploration

Okeanos Explorer, image: NOAA Office of Ocean Exploration

After three days working evenings on Night Processing, I am still learning the procedure. There are many steps involved in processing the sonar data. I was fortunate to have the opportunity to work on SNOW data. It was exciting to be the first person to see the bathymetry of uncharted seafloor. It is amazing to think that only 1% of the world’s oceans have been mapped. The future for aspiring hydrographers looks bright. And that brings me to the topic of my final Teacher at Sea Science log: what’s in store for the future. Talking with the crew, observing and listening to stories, two projects that people on the Rainier are or will be involved with captured my interest: Okeanus Explorer and Autonomous Underwater Vehicles, (AUVs).

In 2008, NOAA will commission an ocean exploration ship, Okeanos Explorer. It’s currently in Seattle, WA which is, coincidentally, the homeport of the Rainier. Rainier’s Chief Steward suggested that I read about the Okeanos Explorer because it has an interesting educational mission. That seemed like a great idea, and I discovered that the Chief Boatswain from the Rainier will be moving to the Okeanos Explorer when it is deployed. So, I looked it up at, “Okeanos Explorer: A New Paradigm for Exploration”, where I found the following information. The Okeanos Explorer will be dedicated to exploring the world’s oceans with a threefold mission: deep water mapping; science class remotely operated vehicle (ROV) operations; and real-time ship to shore transmission of data. Scientists, educators, students and the Chief Boatswain from the Rainier will be participants in ocean exploration in much the same way that I was part of project SNOW (see above).

Through ship personnel there is also a connection between NOAA Ship Rainier and Autonomous Underwater Vehicles (AUVs). Recently, I talked with a visiting Survey Technician who was programming as he spoke. The keyboard seemed an extension of his fingers. His regular job in Silver Spring, MD turned out to be in research for developing and improving AUVs. AUVs are unmanned, underwater robots that can use their sensors to detect underwater mines, objects of archaeological interest or for mapping the seafloor. This was fascinating to me, and I asked many questions.  Last summer, 2007, I had followed the day-by- day log of the Icebreaker Odin in the eastern Arctic Ocean. On this expedition two AUVs, named PUMA and Jaguar, were used to explore and map below the ice on the Gakkel Ridge. In part their mission was to search for hydrothermal plumes or vents. AUVs and their potential are probably as interesting to ocean explorers as the Mars Rover is to NASA scientists. I found out more about NOAA’s role in exploration with AUVs at “AUVfest 2008: Navy Mine-Hunting Robots help NOAA Explore Sunken History”.  

Personal Log 6: Back on the Bridge, Headed Home 

An AUV demonstrates its ability to sense and respond to its surroundings.

An AUV can sense and respond to its surroundings.

As we transit from the survey area to Homer, AK, I have time to reflect on what I will take away from this experience. Again, I am pleasantly interrupted by trips to the Bridge to look at whale spouts and the endless display of volcanic mountains, islands and sea. We’ve made a stop en route for the anglers aboard, and I periodically race back to the fantail for photos of fish, and fishermen and women. But, my thoughts keep returning to, how to make an experience like this real for students. I believe that a research experience and interaction with scientists can make an impression on a student that will last a lifetime. I want students to ask questions and be able to find the resources to answer them. On this voyage I have learned how scientists map the seafloor, and like NOAA I am interested in finding even more ways to use the data.  The Hydrography branch of NOAA recognizes that seafloor maps are a valuable resource that can have multiple uses in addition to producing nautical charts for safe surface navigation. They are looking for ways to, Map It Once: Use Many Times. I had in mind something catchier like, Hydrographic Survey: Ocean Window, but the thought is the same. I like the idea of something called Hydrographic Survey Highlights.

Students could see seafloor discoveries or mysteries from the most recent surveys, and then use NOAA resources to discover what they are or what seafloor features they represent. A good example would be the images of the volcanic plume surveyed by the Fairweather in Dutch Harbor, AK this summer. Another question I have had while surveying the seafloor around Pavlof Volcano is, “Is it glacial, or is it volcanic?” Perhaps I will use one of those topics for a lesson plan when I get back.

I want to close my Teacher at Sea logs by saying that I have had the time of my life, and am willing to come back again if the Rainier ever needs me.

Here are some resources for looking at hydrographic survey data:

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Lisa Hjelm

Lisa Hjelm, August 9, 2008

NOAA Teacher at Sea
Lisa Hjelm
Onboard NOAA Ship Rainier
July 28 – 15, 2008

Mission: Hydrographic Survey
Geographical area of cruise: Pavlov Islands, Alaska
Date: August 9, 2008

A survey technician night processing on the Rainier

A survey technician night processing on the Rainier

Science and Technology Log: Ping to Chart … 

For the past three days I have been Night Processing. That may sound confusing, so I’ll explain. Instead of going out to sea to collect data, I have been processing the data that comes in from the launches. I can’t begin my job for the day until the evening. Survey technicians rotate between collecting and processing data. This science log will summarize the steps that go into turning raw hydrographic data into a navigational chart. Beginning right after dinner, three, four or five, (depending on how many launches were out that day) survey technicians get right to work processing data. CTD casts are used to calculate sound velocity throughout the water column. Night processors take that sound velocity data and apply it as a correction to the raw bathymetry data collected by the launch. Next, the raw data is corrected for the heave of the boat (wave action), and finally for the influence of tides. Then all of this corrected data is merged, and a preliminary base surface (seafloor surface) is created for the bathymetry data.

A preliminary bathymetry chart posted in the Mess.

A preliminary bathymetry chart posted in the Mess.

To check the preliminary base surface, it is viewed with the corrected raw data overlaid. The night processor scans each line of the merged data and looks for anomalies, variations from the norm that might have skewed the base surface. This scan is a time-consuming process. To an outsider it looks a little bit like playing a computer game. Each survey line is divided into small increments and scanned in cross section. Any obviously anomalous data points are highlighted and eliminated. Once the day’s charted area has been scanned and cleaned, the new data is merged with other days’ work. Gradually, building day by day, an entire work area is charted.  To make this process manageable over a sizable area, the survey is divided into sections. Each survey technician is responsible for a section, or sheet. When all of the data has been collected and reviewed, the survey technician writes a scientific report that discusses any data quality  issues, and the work that was done. Other information collected, such as bottom sample data, is included in the scientific report. The sheet is compared with the existing, current chart and also with the bordering sheets. The completed field sheet is sent to the Pacific Hydrographic Branch (PHB) in Seattle where it is reviewed and checked for quality. Finally, the sheet is sent to the Marine Charting Division (MCD) in Silver Spring, MD. The Marine Charting Division chooses the actual soundings that will appear on the chart and publishes it.

An important exception to this step by step process occurs when a danger to navigation is discovered. Dangers are fast tracked, and the information is released to the public almost immediately.

The current chart on the Bridge. The red circle indicates the area in the bathymetric map to the left.

The current chart on the Bridge. The red circle indicates the area in the bathymetric map above.

Personal Science Log: There Ought to be Vents 

Each year my sixth grade science students at Crossroads Academy use one of the NOAA Ocean Explorer Expedition websites for a research project. The students ask a question, and then use NOAA resources to answer the question and write a lab report. This is a challenging project for sixth grade students, so I think some of my students will enjoy reading about how I have used the Teacher at Sea experience to “practice what I preach.”

Vocabulary: Hydrothermal vents -places on the seafloor where warm or hot water flows into the ocean. They are found in areas where there is volcanic activity. The hot, acidic fluids may carry dissolved metals that can precipitate to form ore deposits.

Pavlov Island volcano on the Alaska peninsula

Pavlov Island volcano on the Alaska peninsula, AK Observatory Program

I must confess that along with my Mission from NOAA to perform the duties of a Teacher at Sea (TAS), I came aboard Rainier on a mission of my own. I came to see volcanoes, and even more specifically, I dreamed of discovering volcanic activity or active hydrothermal venting on the seafloor. For as long as I can remember I have been interested in ore deposits that form at vents.

Before becoming a teacher, I mapped and studied ore deposits that formed millions of years ago. It would be very exciting to find evidence of an active vent here in Alaska. That evidence might be: cone shaped or cratered features on seafloor bathymetry maps; floating pumice; gas bubbling on the sea surface; local seawater color changes; and seismic activity (Carey and Sigurdsson, 2007).  By searching the NOAA Vents website I was able to confirm that anomalous values detected by the CTD (Conductivity, Temperature, Depth sensor) instrument (described in log 2) can also be used to help locate hydrothermal vents. Prior to the cruise, I researched the geology of the area as best I could without knowing the exact location of our work area. When I arrived at Rainier, I knew there would be active volcanoes nearby, and I was ready to go.

Approximate area of the current survey with nearby volcanoes indicated.

Approximate area of the current survey with nearby volcanoes indicated, Observatory Program

So far I haven’t seen evidence of hydrothermal venting, no floating pumice, discolored or bubbling water, and the Alaska Volcano Observatory, hasn’t reported seismic activity here within the last month. I have learned how to take a CTD cast, observed volcanic and glacial features in the local landscape, and studied the preliminary bathymetry posted on a chart in the Mess. I am not disheartened nor dissuaded from my quest. In fact, I am encouraged by news from the Office of Marine and Aviation Operations (OMAO) Newsletter for the weeks of July 21 through August 4, 2008 where I read the following report.

Oscar Dyson and Fairweather:  In late June, Oscar Dyson responded to a request from the Office of Coast Survey to investigate a reported area of discolored water outside Dutch Harbor. Dyson confirmed the discoloration during a transit and took a water sample that suggested a possible plankton bloom.  OCS and OMAO then tasked Fairweather to investigate the anomaly during a scheduled transit. Fairweather personnel also confirmed the discolored water, and surveyed the area with the ship’s hull-mounted multi-beam echosounder systems. This revealed a group of small mounds rising a few meters off the seabed in about 100 meters of water directly below the area of discolored surface water. The sonar trace indicated that at least one of these features appeared to be actively emitting a plume of fluid or material. Based on a chartlett produced from the scan, OCS does not believe that these features pose any hazard to surface navigation.  These results have been shared with the U.S. Coast Guard and the Alaska Volcano Observatory, as well as NOAA’s National Weather Service, Pacific Marine Environmental Laboratory, and Office of Ocean Exploration and Research.

Rainier and I are only about 200 miles east of active hydrothermal vents. I have resisted the urge to shout, “Turn the ship around and head west!” After all, when compared to the vast territory that is Alaska, Dutch Harbor is right next door.

References: Carey, Steven, and Sigurdsson, Haraldur. 2007. Exploring submarine arc volcanoes. Oceanography, 20, 4: 80-89.

To learn more about discovering hydrothermal vents and to watch a submarine volcanic eruption, check out the websites below.

Katie Turner, July 25, 2008

NOAA Teacher at Sea
Katie Turner
Onboard NOAA Ship Miller Freeman
July 10 – 31, 2008

Mission: Pollock Survey
Geographical Area: Eastern Bering Sea
Date: July 25, 2008

Bald eagles are abundant around the port in Dutch Harbor

Bald eagles are abundant around the port in Dutch Harbor

Weather Data from the Bridge 
Visibility: 10 nautical miles
Wind Direction: 075
Wind Speed: 13 knots
Sea Wave Height: 1-2 feet
Swell Wave Height: 3 feet
Seawater Temperature: 7.1˚C.
Present Weather Conditions: Cloudy, 9.3˚C, 94% humidity

Science and Technology Log 

After spending 3 weeks at the dock in Dutch Harbor, MILLER FREEMAN finally began the cruise with less than a week left to complete the study. We pulled away from the dock Thursday afternoon, 24 July, and sailed to nearby Captain’s Bay to calibrate the acoustic instruments.

A line diagram of MILLER FREEMAN showing the location of the centerboard below the hull

A line diagram of MILLER FREEMAN showing the location of the centerboard below the hull

Background 

Acoustics is the scientific study of sound: its generation, transmission, and reception.  Sound travels in waves at known rates, and the physical properties of the material the waves travel through affect the speed of sound.  These properties of sound waves enable their use in medical diagnosis, testing critical materials, finding oil-bearing rocks underground, and counting fish in the ocean. Sound travels through seawater of average salinity about 5 times faster than through air (~1,500 m/s, or about 15 football fields in one second).  Many animals that live in the ocean rely on sound more than vision for communication and survival. You are probably already familiar with echolocation and communication vocalizations in whales and porpoises.

Picture of the transducers in the centerboard, which is lowered when the ship is at sea. Lowering the transducer away from the hull reduces the noise interference of bubbles running along the hull while underway.

Picture of the transducers in the centerboard, which is lowered when the ship is at sea. Lowering the transducer away from the hull reduces the noise interference of bubbles running along the hull while underway.

The speed of sound in water increases as temperature and salinity increase.  It also increases with depth due to the increase in pressure.  Therefore, in order to know the speed of sound at a given location in the sea, you need to know the temperature, salinity, and depth. There are other factors that are important to consider as well.  As sound travels through seawater it loses energy because of spreading, scattering and absorption.  When sound waves strike bubbles, particles suspended in the water column, organisms, the seafloor, and even the surface, some of the energy bounces off or is scattered. When the sound energy is scattered at angles greater than 90 degrees it is referred to as backscatter.

Fish Assessment 

Scientists use acoustics to measure fish abundance in the ocean by emitting sound waves at specific frequencies and then measuring the amount of backscatter.  Different organisms and other objects will have a characteristic backscatter that is dependent on many biological factors as well as the physical properties of the medium. The most important biological factor is presence and the size of a swim bladder, but also the organism’s size, shape and orientation.  If scientists know the backscatter signature of the target species (which can be determined experimentally or by mathematical models), they can use sound to identify and measure certain fish populations in the ocean. Onboard the ship, sound waves are emitted from an instrument called a transducer, which is located in the centerboard of the ship. The transducer generates sounds directly beneath the ship into the water column below (pings).  When these sound waves are backscattered from the fish below back to the transducer, they are converted to an electrical signal that is sent to the scientist’s computer.  There, a profile can be created that represents the fish in a graphical image.

Chief Scientist, Patrick Ressler, attaches calibration spheres to the line that will be lowered beneath the ship.

Chief Scientist, Patrick Ressler, attaches calibration spheres to the line that will be lowered beneath the ship.

Before making any actual measurements during this study, it is necessary to calibrate the acoustic instruments on board the ship. Calibrations of instruments and other measuring devices are done by using a known standard to compare the output of the instrument. So for example, if I wanted to calibrate a stick as a measuring device, first I would compare its length to a known standard such as a ruler. We anchored in Captain’s bay, on both bow and stern to keep the ship from moving much, and spheres with known acoustic properties were suspended beneath the ship at a known distance below the transducers. Acoustic data were then collected on backscatter from the spheres. Knowing the distance to the spheres, their acoustic qualities (how they will backscatter the sound), and the physical qualities of the medium (seawater temperature and salinity) allowed the scientists to standardize their equipment.   While acoustic calibrations were performed by the scientists, the survey technicians collected seawater temperature and salinity. The way these properties are measured is standard practice on research vessels.  An instrument package called a “CTD” measures conductivity (which is converted to salinity), temperature, and depth.  Sensors for each of these make up the package, and are mounted on a metal frame called a rosette. The rosette is lowered into the water column by a crane, and the data collected is transmitted via a cable to a computer on board. Once the calibration and CTD measurements were completed, we pulled anchor and headed northwest into the Bering Sea to meet up with NOAA Ship OSCAR DYSON.  We expect to reach our rendezvous point by late Friday to begin our study.

Survey Technician Tayler Wilkins monitors the CTD data transmission while communicating with the crane operator as the rosette is lowered through the water column. The computer automatically produces a profile of temperature and salinity with depth.

Survey Technician Tayler Wilkins monitors the CTD data transmission while communicating with the crane operator as the rosette is lowered through the water column. The computer automatically produces a profile of temperature and salinity with depth.

Personal Log 

The long stay in Dutch Harbor made the departure that much more exciting.  I am looking forward to what little time is left.  The crew of MILLER FREEMAN have all made me feel welcome, and have been helpful in answering my questions and educating me on shipboard operations.

New Terms 

acoustics, calibration, backscatter, centerboard, transducer, CTD rosette

Learn more here 

Katie Turner, July 18, 2008

NOAA Teacher at Sea
Katie Turner
Onboard NOAA Ship Miller Freeman
July 10 – 31, 2008

Mission: Pollock Survey
Geographical Area: Eastern Bering Sea
Date: July 18, 2008

The ship

The ship

Science and Technology Log 

Where is the Bering Sea?

Where is the Bering Sea?

The Vessel 

NOAA Ship MILLER FREEMAN is a 215 foot fishery and oceanographic research vessel, and one of the largest research trawlers in the United States.  She carries up to 34 officers and crew members and 11 scientists.  The ship is designed to work in extreme environmental conditions, and is considered the hardest working ship in the fleet.

She was launched in 1967 and her home port is Seattle, Washington. MILLER FREEMAN has traditionally been used to survey walleye pollock (Theragra chalcogramma) in the Bering Sea.  These surveys are used to determine catch limits for commercial fisherman.  In 2003 NOAA acquired a new fisheries research vessel, the NOAA Ship OSCAR DYSON. OSCAR DYSON is to eventually take over MILLER FREEMAN’s research in Alaskan working grounds, allowing MILLER FREEMAN to shift her focus to the west coast. OSCAR DYSON was built under a new set of standards set by the International Council for the Exploration of the Sea (ICES), which reduces the amount of noise generated into the water below, while MILLER FREEMAN is a more conventionally-built vessel which does not meet the ICES standards.  The assumption is that marine organisms, including pollock, may avoid large ships because of the noise they make, thus altering population estimates.  It is therefore important for scientists to know the difference between population estimates of the two ships. This is done through vessel comparison experiments, in which the two ships sample fish populations side by side and compare their data.  The primary purpose of this July 2008 cruise is to complete a final comparison study of the two ships and measure the difference in the pollock population data they collect.  

Image of the eruption of Okmok, taken Sunday, July 13, 2008, by flight attendant Kelly Reeves during Alaska Airlines flights 160 and 161.

Image of the eruption of Okmok, taken Sunday, July 13, 2008,
by flight attendant Kelly Reeves during Alaska Airlines
flights 160 and 161.

The Location 

The Bering Sea covers an area of 2.6 million square kilometers, about the size of the United States west of the Mississippi.  The maximum distance north to south is about 1,500 kilometers (900 miles), and east to west is about 2,000 kilometers (1,500 miles).  The International Date Line splits the sea in two, with one half in today and the other in tomorrow. The area is also bisected by a border separating the Exclusive Economic Zones (EEZ) of Russia and the United States. The EEZ is the area within a 200 mile limit from a nation’s shoreline; where that nation has control over the resources, economic activity, and environmental protection. More than 50% of the U.S. and Russian fish catch comes from the Bering Sea. It is one of the most productive ecosystems in the world.  The broad continental shelf, extensive ice cover during the winter, and the convergence of nutrient-rich currents all contribute to its high productivity. It is a seasonal or year round home to some of the largest populations of marine mammals, fish, birds, and invertebrates found in any of the world’s oceans.  Commercial harvests of seafood include pollock, other groundfish, salmon and crab.  The Bering Sea has provided subsistence resources such as food and clothing to coastal communities for centuries.

Aleutian Island volcaneos

Aleutian Island volcaneos

Repairs and Delays 

Anchorage high school teacher, Katie Turner, arrives at the pier in Dutch Harbor, Alaska

Anchorage high school teacher, Katie Turner,
arrives at the pier in Dutch Harbor, Alaska

While all aboard were anxious to begin this Bering Sea Cruise, the ship could not sail until crucial repairs could be made.  During the previous cruise a leak was discovered in the engine cooling system that brought the ship in from that cruise early.  The location of the leak was the big mystery.  After days of testing and a hull inspection by divers the leak was located.  It was in a section of pipe that runs hot water from the engine through the ship’s ballast tanks and into a keel cooler on the outside of the ship’s hull, where it is cooled before circulating back to the engine. This turned out to be a very labor intensive job and workers spent days draining and cleaning the tanks before the leak could be repaired.

In the meantime, a repair to one of the engine’s cylinders required a part that had to be shipped from Seattle via Anchorage (about 800 miles northeast of Dutch Harbor). To complicate the arrival of this part, a nearby volcano erupted, spewing ash 50,000 feet into the path of flights to and from Dutch Harbor.   Alaska has many active volcanoes. The Aleutian Island arc, which forms the southern margin of the Bering sea, comprises one of the most active parts of the Pacific’s “ring of fire”. This tectonically active area has formed due to the subduction of the Pacific plate beneath the North American plate. So far we do not have a definite departure schedule.  Each day spent at the dock is one day less for the scientific team to complete the goals of the cruise.  Meanwhile, OSCAR DYSON is completing its survey in the Bering Sea, and anticipates the arrival of MILLER FREEMAN to complete the comparison study.

NOAA Teacher at Sea, Katie Turner, gets a tour of the bridge and quick navigation lesson from Ensign Otto Brown

NOAA TAS, Katie Turner, gets a tour of the bridge and quick navigation lesson from Ensign Otto Brown

Personal Log 

I arrived in Dutch Harbor on July 9th with a forewarning that repairs to the ship would be necessary before heading out to the Bering Sea, and that I would have some time to explore the area. I have managed to keep busy and take advantage of opportunities to interview the crew, hike, and find my way around town. The weather in Dutch Harbor has been exceptional with many sunny days. It’s uncommon for a NOAA research ship to spend so much time at the dock, and we attracted the attention of a newsperson from the local public radio station. Commanding Officer Mike Hopkins and Chief Scientist Patrick Ressler were interviewed by KIAL newsperson Anne Hillman while MILLER FREEMAN was delayed for repairs in Dutch Harbor. Unalaska Island has few trees and along with other islands on the Aleutian chain is known for its cool and windy weather. There are no large mammals such as bear on the islands but small mammals, such as this marmot, are common along with many species of birds and a wide variety of wildflowers, which are in bloom this time of year.

Chief Scientist Patrick Ressler explains how he uses acoustic equipment to study pollock in the Bering Sea.

Chief Scientist Patrick Ressler explains how he uses acoustic equipment to study pollock in the Bering Sea.

A marmot spotted on a ridge alongside the road up Mt. Ballyhoo on Amaknak Island

A marmot spotted on a ridge alongside the road up Mt. Ballyhoo on Amaknak Island

A Bald Eagle guards the crab pots stored near the pier

A Bald Eagle guards the crab pots stored near the pier

The view from Mt. Ballyhoo on Amaknak Island. Lupine, a common plant found on the island, is in bloom in the foreground

The view from Mt. Ballyhoo on Amaknak Island. Lupine, a common plant found on the island, is in bloom in
the foreground

Black Oystercatchers take flight over the harbor

Black Oystercatchers take flight over the harbor

Learn more about the Bering Sea ecosystem at these Web sites: 

http://www.avo.alaska.edu/volcanoes/aleutians.php http://www.worldwildlife.org/what/wherewework/beringsea/index.html http://www.nature.org/wherewework/northamerica/states/alaska/preserves/art19556.html http://www.panda.org/about_wwf/where_we_work/europe/what_we_do/arctic/what_we_do/marine/bering/index.cfm