Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Saturday, August 19, 2023
Weather Data Lat 58.1 N, Lon 150.1 W Sky condition: Partly Sunny Wind Speed: 5.81 knots Wind Direction: 346.98° Air Temp: 12.91 °C
Science Log
The last trawl sample that the OscarDyson’s crew and scientist’s took was in deep water with a Methot net, named after Dr. Rick Methot, the NOAA scientist who developed it. This type of trawl net slows down the water as marine organisms tumble into it, so their delicate bodies are not crushed. The codend looks a lot like what you would see in a plankton tow, only it will catch a lot more organisms.
Michal Levine as he removes the codend from the Methot trawl net
Sub-samples are taken from what the Methot catches. Some krill is preserved and sent back to NOAA in Seattle for identification and analysis. On board, the krill are weighed and counted. The krill and other organisms are small, so the tools used to sort them are designed for capturing and moving small organisms.
The tools used to sort krill
Krill
After the last krill was counted and weighed, the science team quickly jumped into action cleaning up the Fish Lab. Yes, I am including this in the science log, because cleanup is an important part of science that many high school students seem to forget.
Totes and baskets were scrubbed and then washed with a pressure hose
The crew had unreeled the trawl nets and were getting ready to ship them to Washington state.
Trawl nets neatly stacked on deck
Personal Blog
Being a Teacher at Sea on the Oscar Dyson was a fantastic way to end the summer for me. Shortly I will be heading back to Anchorage where high school has already started and students have already been to my class with a substitute teacher. I look forward to teaching school, but am so thankful for the opportunity to have this adventure.
It has been so wonderful working with the science team on this cruise. After so many unforeseen delays the objectives were met through team work and the organizational skills of the lead scientist Taina Honkalehto.
The people on this ship really enjoy working on the ocean. Whether it is captaining the boat, engineering, the mess, to programming echo sounders, identifying species of fish, weighing and sampling them, they all love what they do. They also really care about the work that they are doing, the health of the ocean, and they want to support the people working and living with it. Also, there is a unique brand of humor that comes with working together for extended periods of time at sea. You just have to laugh at strange fish that come aboard and wonder at the beautiful sunsets or northern lights.
A Grenadier fishSunset at Montague islandAurora from the aft deck
On the bridge I found the ship’s communication flags. These flags are a way to communicate with other ships if the radios are not working or to hang on holidays with a message. When I was a kid back in Ketchikan, Alaska, I admired the flags so much I would draw cartoons with flag messages. So, to NOAA, the science team and the crew of the OscarDyson…
T
H
A
N
K
S
May the seas lie smooth before you. May a gentle breeze forever fill your sails. May sunshine warm your face, and Kindness warm your soul. – An Irish Sailor’s Blessing
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Friday, August 18, 2023
Weather Data Lat 58.18 N, Lon 148.82 W Sky condition: Partially Cloudy Wind Speed: 10.55 knots Wind Direction: 32.58° Air Temp: 14 °C
Science and Technology Blog
Meet Sandi Neidetcher, she is a fish biologist investigating fish reproductive status. Why care about fish reproduction? Well, the seafood industry is extremely important to Alaska and other coastal states. And they would not have an industry if those “little fishes” could not reproduce. But the ocean is changing due to climate and different types of pollution.
Climate change is making our oceans a warmer place—just a couple of degrees, but that may be enough to really change how fish reproduce and spawn. A few degrees in temperature could change when and where fish reproduce, and then cascade to the fishing industry, the food market, and the people who depend on them as food.
NOAA wants to have background information on fish reproduction so they can recognize whether the fish have changed their reproductive strategies over time and how that could impact fisheries.
Sandi received her Masters degree studying the ovaries of Pacific cod to determine the phenology and geography, or the timing and location, of spawning. She specialized in histology, which is the study of microscopic tissue structures, for her it was specifically the ovaries. To understand the reproductive process and ovary maturation, she studies slides with ovary tissue mounted and stained to show oocyte (unfertilized egg) structures that develop as the spawning season progresses.
Examples of histograms from Sandi’s research, showing the progression of Pacific cod oocyte structure development over the course of the spawning season
Now she is involved in a study looking at the reproductive states of Walleye Pollock. Pollock are multi-batch spawners. They have the ability to spawn (lay eggs) more than once in a season. So the female ovaries can be in different stages of reproduction throughout the season.
The first step in this analysis is to collect the ovaries from the pollock.
Sandi Neidetcher and Robert Levine work together to collect data on a pollock.
In the photo above, the fish will be measured for length and weight, then the ovary and the liver will be removed, weighed, and saved for analysis. The fish’s ear bones (otoliths) will also be removed and used to determine its age. Samples are sent back to Sandi at NOAA AFSC (Alaska Fisheries Science Center) in Seattle, Washington. Half of the ovary will be sent to a histology lab where technicians will prep the tissues and return the sides ready to be analyzed. The other half of the ovary is scanned on the ship.
Sandi is comparing the histological samples to Raman Spectroscopy Analysis that she does aboard the OscarDyson. A long time ago when I was an undergraduate student in chemistry, Raman spectrometers were very large. The one I worked with in my physical chemistry class was in the basement of a building on a special concrete slab that stopped any vibrations from disturbing the path of the laser. Did I mention that the whole setup took up almost half of the basement?
The computer displays a scan of the ovarian tissue
Raman spectrometers have come a long way since my undergrad. Today, Sandi has a small wand that contains a laser connected to a spectrometer the size of a donut box. A small desktop computer connected to the spectrometer will give an immediate readout of the analysis.
The wand with the laser is held over the ovary to collect data on large macromolecules like lipids, proteins, and DNA.
You can see the laser light as it penetrates the ovary.
The analysis that Sandi does is to compare the molecular composition identified through the spectral patterns with the structures seen in the histology samples, and to determine if the maturation status can be identified through the spectral patterns. The ultimate goal would be to have a small hand-held spectrometer that a scientist could use right as the ovaries are extracted. This would greatly increase the amount of ovaries analyzed quickly and efficiently and reduce the cost and time required for histological analysis
Sandi at her work station on the Oscar Dyson
Pollock have variability in their reproductive strategies and may be impacted by environmental conditions. One strategy is down regulation, where a fish will reabsorb a number of eggs during maturation and, as a result, reduce the resources spent on reproduction. This reduces the fecundity, or number of eggs released by that fish in a season. Knowing how fecund a fish population is helps managers determine how many fish can be removed by a fishery. Atresia is the resorption of an oocyte and can be seen histologically. Mass atresia is where a whole ovary of oocytes is be reabsorbed. If the fish is not finding enough food or the temperature is not correct then, then a female fish can save energy by reducing, or stopping the whole process of reproduction.
Recent warming sea temperatures have been seen in the Gulf of Alaska, and this may be impacting fish reproduction. In 2020, the number of Pacific cod predicted had dropped so low that the federal waters fishery was closed. That same year, crew fishing for Pacific cod reported seeing a number of Pacific cod with mass atresia. Scientists do not know if the observation of atresia, during a warming period, is related to the population crash but studies like this will give more information for the future. Predicting population crashes that may be related to climate change, fish health or temperature differences are an important part of fisheries management and impact us all because the ocean is an important resource.
Personal Blog
Crew Members in the Spotlight
Pictured left to right, Juliette Birkner – Engineering, and Ben Boswell – Survey Technician
The Commanding Officer runs the ship, but there are many important jobs that the OscarDyson would not function without. Engineering is one of them. There is a small team of Engineers aboard that are constantly monitoring the ship when on shift.
Juliette is a member of the OscarDyson’s Engineering department and may have been on the staff the longest. Her personality is direct, friendly and capable. Before becoming an Engineer, she attained her bachelor of science degree at the University of Washington. After receiving her degree she did not really have a clear plan for a job. So she went to a community college and received the equivalent associates degree of a Junior Unlicensed Engineer. Eventually, through NOAA, she can be a fully qualified Engineer with time aboard ships.
Juliette has a wildly creative side and interest in science. The scarf she is wearing in the picture has different layers present in sedimentary rock. She is also a big fan of dinosaurs, placing several all over the ship for people to find when work is slow. Honestly, it is the kind of humor that keeps everyone moving around with a smile. Some dinosaurs even have sweaters that she knitted, in her down time. Her knitting is extremely impressive.
Ben is the Survey Technician for the ship. Survey Technician is the kind of job you would never know exists as a high school student. There are jobs out there in this world that people would never specifically train for in high school or college , but are highly needed where you have different groups collaborating in complex situations. Ben’s job description is a pretty long list; calibrate scientific instruments, collect data, assist scientists, help the deck crew, and act as a liaison between science and the deck crew.
How did he arrive at this position? He attained a bachelor of science in Wildlife Biology and worked in the field for a while. Unfortunately, he found the job hard to make a living with the low pay. Fishing’s siren song came in the form of factory trawling and other crew positions in smaller boats. Because of his academic training and work experience the “perfect storm” of a Survey Technician was born.
Soon we will be taking our last trawl sample and heading to port in Kodiak. There have been moments on the cruise where time crawled in the dead of night while I was struggling to stay awake. Mostly, it has been a trip of a lifetime, with an incredibly capable and adaptive team of scientists and crew members willing to share stories that keep you awake and lull you to sleep, dreaming about tomorrow.
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Wednesday, August 16, 2023
Weather Data Lat 59.47 N, Lon 144.1 W Sky condition: Cloudy with Rain Wind Speed: 22.62 knots Wind Direction: 125.44° Air Temp: 14 °C
Science and Technology Lab
While on the third leg of our cruise we have had a lot of weather delays, so when the going gets rough the Oscar Dyson science team calibrates! Plus they do not hesitate to work on a couple special projects. No time is wasted. In a secluded bay, waiting for the storm to pass, lots of work can be done to further science.
As I mentioned, this summer has been cold, dark, rainy, and windy. As a fisher person who works in this environment, I cannot overstate how important the internet has become with weather apps like Windy. They accumulate data from oceanic buoys, local weather stations, and satellite images to create a picture like the one you see below.
This image is from the weather app Windy. The white lines indicate the wind direction and the warmer colors are higher wind speeds.
The crew and scientists were able to be proactive in their decision to find a safe place to harbor and then could set up a work plan through the weather day.
Calibration of the Ships Echosounders
The Oscar Dyson’s echo sounders get calibrated about four times a year, at the start and end of the winter and summer field seasons. Because this is the last leg of the cruise, and we are nearing the end of the summer, a weather day is a good day to make sure they are working well
The first step in calibration is to set up down riggers on the starboard, port and aft decks.
From left to right Abigail McCarthy, Robert Levine and Matthew Phillips, part of the night crew, head outside to place the down riggers.
Once placed, the downrigger lines are very cleverly connected underneath the boat, so all three lines meet.
Downrigger mounted on a railing
Where all three lines meet, a single line is suspended directly down underneath the keel of the boat where the echo sounders are located. The down line has a tungsten carbide sphere suspended above a lead weight. The scientists use the known target of the sphere and the known properties of the water column to figure out the difference between expectations and reality in their calibration. The tungsten carbide sphere works extremely well for calibration because it is extremely dense when compared to water, has a known sound reflection, and allows calibration at multiple frequencies.
Pictured above is a screen scientists see as they are moving the sphere around for calibration.
The picture is showing a black circle representing the transducer face as observed from above. The blue dots represent individual measurements of the reflected echo of the calibration sphere as it is moved around in the transducer beam. Using this calibration software the scientists can evaluate the measurement sensitivity and the beam characteristics of the echo sounders.
Calibrating the acoustics was not the only event that happened while weathered deep in a fjord arm of Nuka Bay.
The MiniCam
While waiting out the weather, other members of the science team had a chance to work with a new piece of equipment called a minicam.
The MiniCam, pictured above, has two stereo cameras which can film marine organisms.
The purpose of this camera is to connect the images it records to the backscatter shown with the Oscar Dyson‘s echo sounders. Again, backscatter, as I mentioned in the previous blog, are images that are produced when the echosounders’ different frequencies are reflected back to the ship. The images created by sound are shown on a computer screen and can be used to identify different species of fish or other marine organisms. The images need to be verified by either the minicam or trawl sampling. Scientists want to make sure that the length and species of what they see in the camera can relate to the scaling of the backscatter. The minicam was deployed by scientists and the crew several times to look at the fish and euphausiids in the water column, while we waited out the bad weather.
Getting ready to suspend the MiniCam before it is lifted over the side of the boat from the Hero deck.
Recreational Fish Finders “Little Pingers” Project
This is a project by NOAA oceanographer Robert Levine. The echosounders that are suspended below the Oscar Dyson are extremely precise and expensive. Robert and a colleague want to compare the echosounder’s data/readout for recreational fish finders to the echosounders on the Oscar Dyson. There are situations where scientists would love to monitor fish and marine organisms’ populations, but may not need the accuracy and precision of the scientific Simrad echosounders.
Robert Levine working with the ” Little Pingers.” Environments on board a ship can be challenging to work in, as seen here.
They also might not be able to recover the fish finders, so having them less expensive is very important.
At this point they are just collecting data and monitoring performance with the recreational fish finders, affectionately called “little pingers.” Later in the project they will do more of a data comparison to the Oscar Dyson‘s echo sounders.
Personal Log
On board a ship, one way to keep the crew’s spirits up in bad weather is excellent food. According to the people I have worked with so far on the cruise, the meals on this leg of the acoustic-trawl survey have been amazing.
Meet The Dream Galley Team
From left to right, Rodney Bynum and Angelo Santos
Meet the Dream Galley Team. From left to right, Rodney Bynum and Angelo Santos. These men share a passion for food and see how it brings smiles to the faces of their customers, friends, and family. Both have fathers who worked on ships in the Steward Department. Rodney fondly remembers his father bringing home exotic food from all over the world. His father inspired him to open a Soul Food restaurant in Norfolk, Virginia. Years later, Rodney decided to take his culinary career in a different direction: cooking on a ship. The Oscar Dyson was his first time working on a ship and he has really enjoyed it thus far. The crew loves his congenial personality, mad cooking skills, and awe-inspiring work ethic.
Angelo started cooking at the age of 11, often helping his mom roll lumpia (Filipino egg rolls) and make other traditional Filipino food while religiously watching Giada de Laurentis, Emeril Lagasse, and Ina Garten on Food Network. Angelo grew up in San Francisco and rural Oregon, spent 3 years in San Diego, and is now based in Oregon once again while traveling the world for work. In Oregon, he decided to major in Culinary Arts and graduated with his associate’s degree after going through Linn-Benton Community College’s Culinary program. Angelo mentioned, “culinary school isn’t required, but it helps you gain a fundamental understanding of cooking to prepare you for the real world.” He recommends trying out a restaurant job before spending money on tuition for culinary school.
East Coast meets West Coast aboard the Oscar Dyson. Both men have solid fundamentals in cooking from their years of experience as restaurant chefs. Angelo is the Chief Steward while Rodney is the 2nd Cook. The Chief Steward is in charge of galley operations while the 2nd cook provides breakfast and assists as needed. Chief Steward is like an Executive Chef position on land while 2nd cook is like a breakfast cook/prep cook/dishwasher. Rodney and Angelo often collaborate for menu ideas and feed off each other’s passion for delicious food.
Both of them enjoyed high school and had lots of advice for students looking into a career in Culinary Arts. As I interviewed them, they’d often finish each others’ sentences in agreement.
Rodney: “If you’re looking to become a good chef, don’t be afraid to taste everything, including food that may not be familiar to you. Every job in the kitchen matters, whether it’s the prep cook, dishwasher, or executive chef. Learn every position and never stop learning.”
Angelo attended culinary school shortly after graduating high school, so he found it to be stressful and chaotic, but very rewarding. He mentioned, “Focus as much as possible on having a good work-life balance. Find the joy in simple pleasures, take care of your mental health, and make friends outside of work. Work on networking with peers who share your passion for food as well as people outside of your cohort. Connections can help a lot.” Angelo enjoys cooking on ships because the compensation was very good. The only chef jobs on land that compare to this salary are executive chefs at very high end venues and private/personal chefs. Being able to travel around the world on business was a cool perk of being a chef at sea.
Overall, both men agreed that some of the best moments of pursuing a career in the food industry have been about seeing the joy that good food brings to people. Life is too short to not eat well and this is especially appreciated when one works on a ship. It makes all the difference for the morale of a ship to know that while you’re away from your loved ones, you can still eat well.
Finally, I have to give Angel credit for helping me write the sections about the “Dream Galley Team,” not only is he a great cook but also a fantastic writer.
This beautiful latte was made by Angelo Santos on the Oscar Dyson
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Sunday, August 13, 2023
Weather Data Lat 59.12 N, Lon 150.11 W Sky condition: Partly Cloudy Wind Speed: 13 knots Wind Direction: 330° Air Temp: 14 °C
Science and Technology blog
The ocean is a really big place. We have really only mapped about 5% of the ocean bottom. How do we manage fisheries if we have to count fish in an area that is overwhelmingly large? This is where the genius of acoustics and trawl sampling complement each other. The scientists aboardNOAA Ship Oscar Dyson use the echo sounders to find fish or other animals lurking in the ocean and then they can extrapolate and upscale that data to a much larger area which is covered by their transects.
Wait! That is a lot of information using language that folks don’t really use at the dinner table. Could you please explain this in more basic terms? You bet, as a matter of fact in the last couple of days I have been swimming in a sea of new vocabulary, talking to really smart people and trying to keep up with the conversation that it almost makes my head explode. Don’t worry, I am safe. But it’s really impressive how scientists have developed ways to accurately know fish and marine organism populations in the ocean with out having to sample all of it.
Acoustics
Acoustics uses the echo-sounders a lot like a fish finder, but the ones on NOAA Ship Oscar Dyson are much more capable than the type you would find on your boat. The echo-sounders are attached to the bottom of a lowered centerboard—essentially a large keel—in the center of the boat, and they measure five different frequencies with different wavelengths.
View of the 5 different frequencies measured by the echosounders, one in each frame. The darker marks on the screen could be fish, jellyfish, krill or other marine organisms, this is referred to as “backscatter.” The red circles show the different frequencies used to measure the backscatter.
So, if we can see the fish using acoustics, why do scientists need to sample using a trawl net? As you can see above, the marks in the backscatter can show the depth and the approximate shape of objects, but there is not enough detail to tell exactly what kind of organism is present. Most of the scientists on board have a pretty good idea what kind of fish or organisms are present, but the most definitive way to know is to take a trawl sample.
Trawl Sampling
The trawl net as seen in the picture below is being set off the aft deck.
The part that is in the air is called the codend. That is the section of the net where the specimens are ultimately collected.
The trawl is a about 172 meters long and it stored on these rollers on the back deck.
When the trawl is deployed to the depth that the scientists want to sample, the net will funnel fish and other organisms into it. This is called flying the net.
The screen above diagrams three different views of the net as it is pulled through the water. You can see that the trawl net was not directly behind the boat and went to a depth of 21.5 m.
In this image you can see the net and how far back it trails behind the Oscar Dyson.
I just have to include one more view of the trawl net from the bridge as it is pulled behind the boat.
This image was taken when the crew was bringing the net back into the boat, so the depth is shallower.
The next image shows the path that the net was pulled through the water.
The acoustics show the backscatter which the scientists make the trawl target. The next step is to process what is captured in the codend of the trawl and see exactly what is present.
Because the trawl is dragged through the water, it catches different organisms at different times. The scientists want to know when the different organisms were caught so they have cleverly attached a camera to the side of the net. Through the camera they can see which type of fish came into the trawl. Ultimately, this links the kind of acoustic backscatter viewed in the echograms recorded during the trawl to exactly the type of organism caught by the trawl.
The camtrawl: a camera that records the type of fish entering the net and when they enter.
Below is a picture of some fish as they enter the trawl net and move towards the codend.
The camera is looking across the net as the fish move past. The fish in the picture are pollock, the type of fish we are looking for on this leg of the cruise.
Transect Lines
So how do scientists take this information and extrapolate the data to a broader area? While the Oscar Dyson is out at sea they run transect lines while recording acoustic data. Transect lines are specific paths in the ocean. The picture below shows the transect lines that we plan to do and have done on this leg of the cruise.
The red lines are the transects we have done and the blue lines are the transects scientists plan to do in the remainder of this leg of the cruise. If you look closely there are pictures of fish symbols on the transect lines where the ship has made trawl samples.
Using the acoustic data that the echo-sounders provide and verifying the types of fish and other marine organisms through the trawl sampling allows the scientists to predict, with a high level of certainty, the amount and types of marine organisms that are present along the transect lines that were not trawl-sampled. Thus saving the taxpayers money, and allowing fisheries managers to use good data, keeping the fishery viable, and allowing commercial fishing boats to have reasonable catch limits.
Scientist in the Spotlight
Honestly it takes a team to make all of this happen. But, half of our team is sleeping at the moment, I have the night shift from 4pm to 4am, so I am going to introduce one fabulous expert in acoustics and fisheries:
Abigail McCarthy in the Acoustics Lab
Abigail McCarthy has been working for MACE: Midwater Assessment and Conservation Engineering Program since 2007. She received her undergraduate degree in Biology from Wellesley College and then obtained a Masters in Fisheries from Oregon State University.
For fun, she surfs and enjoys long-distance prone paddle board races. She has recently found a new love with fly fishing.
Aboard the Ship Oscar Dyson, she is working as a specialist helping to run the acoustics lab.
I asked Abigail what she thought of about her educational experience? She immediately said, “I love learning! High school and college were both a lot of fun.”
What would be a good suggestion for a young aspiring high school student pursuing a degree related to ocean studies or science in general?
Her response was great: “Being curious and working hard is more important than being brilliant. Persistence and determination will get you where you want to be in the future.” Finally, “Learn to code! Become familiar with programing languages like Python and R.”
Hopefully, I answered your burning questions about the use of acoustic trawl sampling, and surveys. Yet, there is so much more to learn. Why not take a trip yourself? Check NOAA’s website out and just apply.
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Friday, August 10, 2023
Weather Data Lat 59.47 N, Lon 149.36 W Sky condition: Cloudy and rain Wind Speed: 23.73 knots Wind Direction: 72.22° Air Temp: 14.47 °C
Science Log
Comparing Set Netting to Trawling
There are many different ways to catch fish. I am comparing set netting, in a little boat, a 24 ft. skiff to trawling on NOAA Ship Oscar Dyson, a big boat which is 208 ft. This is a little bit like comparing apples to oranges; set netting and trawling are different gear types used to catch fish very differently. Set netting targets mostly salmon, while trawling in Alaska targets mostly pollock. Both of these methods of fishing can be used by scientists to collect samples and to catch fish commercially to sell in global markets.
Set Netting:
I am a commercial set netter, which uses a gill net, specifically designed to catch salmon by the gills. Salmon will swim along the shoreline. Set netters place their nets perpendicular to the shore so salmon have to swim around the nets or try to swim through them. When they try to swim through the fish get caught by the gills. Watch the video below on how I pull the net in using a hydraulic roller and pick fish out.
Pulling in the net and picking a Sockeye salmon
[Transcript: Yup, here I am, picking a… Sockeye salmon! Yup, here it is, a beautiful, lovely, amazing Sockeye salmon that I picked. This is what I do in the summer! Yeah!]
When you watch the video you will see the net is a light color that matches the water. Again, salmon do not see the net and try to swim through it and then they are caught. At the end of the video I place the fish in a brailer bag filled with ice and sea water to keep the fish cool. The better the fish are cared for, the better the product that goes to market.
Trawling
Unlike set netting, which is done on a small skiff with just a few people, trawling is done on a large boat with a big crew. The Oscar Dyson has the ability to use echo-sounders to find out where fish are, and then they can lower a trawl net into the water specifically sampling at that depth for fish. A trawl net is like a big bag with are large opening that funnels fish into it.
The Scientists on NOAA Ship Oscar Dyson use a much smaller net than a commercial trawler does to catch fish. They compare what they see on their echo-sounders to what is caught in their net. They use this information to get a general idea of what kind of fish are present in a specific part of the ocean they are sampling. This helps scientists provide accurate information to both the federal and state government to help manage fisheries and keep intact healthy populations of fish.
A commercial trawler will try to catch a specific kind of fish, their target species. If they catch fish other than their target species this is known as bycatch. Large commercial trawlers can have nets up to 50 meters in length, so they can catch a lot of fish. They can only keep and sell their target species. The fish that the Oscar Dyson catches cannot be sold or eaten, but the data the collection provides scientists a great deal about what kind of fish, approximately how many, and at what stages of reproductive development, are located in specific areas of the ocean.
How trawling can impact salmon fisheries like set netting:
Knowing what is happening in a different part of the ocean is very important to other fisheries. Salmon initially develop in fresh water lakes or rivers and then migrate to the ocean. They spend most of their adult life migrating large distances in the ocean, and they depend on food that is present out where the trawlers are fishing. They also may be caught by trawlers as bycatch.
Below is a short sped up video of crew members retrieving a trawl net.
Crewmembers aboard NOAA Ship Oscar Dyson retrieve a trawl net. [No audible dialogue.]
In Alaska there is a bit of controversy over one gear type taking away fish from other gear types. Specifically there is concern about commercial trawling, picking up non-target species like salmon from local coastal fisheries and subsistence users. A lot of the answers may exist in the data that the science team is collecting.
Personal Log
At the beginning of the blog in the weather report you will notice that the wind speed is pretty high at 23.72 knots. A gale is heading towards our area in the Gulf of Alaska. We are finishing a transect line and then heading into a protected bay in the Kenai Peninsula to wait out the weather. While the ship is protected, the science team will work on recalibrating the echo-sounders below the ship. The science team has been experiencing a bit of unexplained noise in one of their lower frequencies. Hopefully, the opportunity to do this calibration will help.
Crew Member in the Spotlight
The Oscar Dyson has a science team and a crew that work together to collect the data for the acoustic trawl sampling and run the ship. Working for NOAA can provide exciting opportunities for young people to experience life on the ocean. When you are on board the ship, you have free lodging and food, which on this leg of the cruise is quite excellent, so you can save money while on board. So far everyone I met enjoys their job and is willing to let me ask them questions about how they got here.
Dee with a picture of the Oscar Dyson in the background
Meet Elvricka “Dee” Daniels from Jacksonville, Florida. She has been on NOAA Ship Oscar Dyson for about 2 months. She was originally temping for an agency in Florida when a friend told her about a subcontractor for NOAA, Keystone. She is currently working as a deckhand for the contractor Keystone.
What does she enjoy aboard the ship?
“Fishing! What kind of different fish come in the trawl net. There is always something different every time we fish.”
She also really likes being on whale watch on the bridge. The science team cannot set out the net if there are whales in the area, so there is always a crew member looking for whales.
As a high school teacher, I like to ask people what their school experience was like. Everyone has a different experience in high school some good some, perhaps not so good, but many go on be successful adults. What was high school like for Dee?
“It was good at first and then it got bad. I made poor choices that impacted my life, I had to go to summer school to make up for missed school. Doing well in school is very important to my family.”
So now here she is out in the Gulf of Alaska helping science happen and impacting others by what she does.
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Wednesday, August 9, 2023
Weather Data Lat 58.16 N, Lon 148.97 W Sky condition: Cloudy Wind Speed: 2.88 knots Wind Direction: 301.28° Air Temp: 12.44 °C
Personal Log
School will soon be starting in Anchorage at Bettye Davis East High School. I will not be in school for the first three days because I am having fun on a teacher’s field trip. Good things come to those who apply for it. I applied and got accepted on this cruise before the pandemic, but life and safety concerns made my journey about three years longer. Finally, I am living the dream and out in the Gulf of Alaska surrounded by pure ocean, whales, seabirds and catching lots of fish.
Kayaking in Prince William Sound with Loki the dog. My family commercial fishes for Sockeye Salmon in Main Bay.
My name is Germaine Myerchin Thomas. I was born and raised in Ketchikan Alaska. I am the daughter of a fishermen and a teacher. I, myself, am a teacher, and I commercial fish in Prince William Sound. So far I have spent most of my summer fishing in the Eshamy district about 45 miles outside of Whittier. It has been a cold dark wet summer( the word “summer” is debatable). Recently, I jumped from Set Net fishing for Sockeye (Red) Salmon, in small open skiffs, to the fabulous NOAAS Oscar Dyson.
Just visualize the ice sculptures, swimming pool and yoga studio on the Lido Deck… nope! The NOAAS Oscar Dyson is a research vessel that you can find more about by clicking the link above. Currently there are 24 crew members and 8 scientists. The ship is outfitted to conduct an acoustic trawl survey, but there are other scientific projects going on during this leg of the cruise. It, also has great food and two gyms. The waves rolling under the hull of the boat make the feel of gravity extra strong while trying to do push ups.
Already I have discovered that working out in the ocean requires being very flexible and adaptable. Sometimes the weather or wildlife can delay setting out the trawl net. Last night the boat was surrounded by whales (Fin and Sei), marine birds (Fulmars, Shearwaters and Black footed Albatross) all enjoying the abundant fish that we wanted to catch in our trawl net. Naturally we just let the animals enjoy the abundance while the scientist patiently waited for their turn in another area.
When the cruise ends I will head back to Anchorage and teach high school, chemistry, oceanography, and marine biology. I am really looking forward to meeting my students for the first time. I hope that I might be able to Zoom into my classroom and share what I am doing while I am out here.
Mission: Acoustic Trawl Survey (Leg 3 of 3) Geographic Area of Cruise: Pacific Ocean/ Gulf of Alaska Date: Monday August 7, 2023
Weather Data Lat 58.31 N, Lon 151.58 W Sky condition: cloudy Wind Speed: 12.43 knots Wind Direction: 357.55° Sea Wave height: 1 ft | Swell: 340°, 1-2 ft Air Temp: 12.35 °C
Science log
The purpose of this trip is acoustic trawl sampling for pollock (Gadus chalchogrammus). There are other projects that people are working on during this leg that I will report on in other upcoming blogs.
Today, at about 5:30 pm we deployed a CTD (Conductivity, Temperature and Depth – Probe). This probe measures the salinity using conductivity, the temperature with a digital thermometer, and records the data all at different depths in the water column. This CTD also records fluorescence which is an easy way to determine the amount of plankton present. The plankton at the surface are producers and have chlorophyll, which reacts to fluorescence and can be recorded. This information will be important when we start taking trawl samples, so the ships crew will routinely send out the CTD while we cover our transects.
Watch the videos below of the crew members deploying and recovering the CTD.
Crew members deploying the CTD
Recapturing the CTD
The data from the CTD collection are shown on the picture of the computer screen below:
CTD Data: Fluorescence, or Chlorophyll (green) and Turbidity (orange) v. Depth on the first graph, and Salinity (yellow) and Temperature (blue) v. Depth on the third graph.
The data from the CTD are presented in graphical form. The first frame shows chlorophyll, which is the green line. The second frame is percent oxygen (which they were not measuring so it remains zero). The third frame shows salinity (yellow line) and water temperature (blue line).
Personal log
Currently we are cruising out to our transect destinations over the continental shelf. The seas are a little rough (6-8 foot waves) and I am enjoying some saltine crackers that help with mild sea sickness. It has been a while since I have been in a large boat in rolling seas.
Three days ago, I flew from Anchorage to Kodiak Island on an a sunny afternoon and met the science team for the cruise. The whole team was extremely welcoming, sharing stories of past cruises, colorful characters and the science behind acoustic trawl sampling. Later, they invited me to go surfing the next day at a beach on the far side of the island.
Through the camaraderie of playing in the waves I was introduced to these amazing people and their knowledge and love of the ocean. They are very professional and willing to share what they are studying. They also have a deep concern for the changes occurring in the ocean and honestly hope that their information can be shared and understood in order to mitigate the impact of change. Sitting on my surfboard I quickly learned I was the beginner, and they were the experts. With the experience of time, they would effortlessly snap up and slice through the waves. Smiles and whoops encouraged each other as the sea crashed into the beach.
Surfing off of Kodiak Island. Photo credit: Mathew Phillips
Surfing off of Kodiak Island. Photo credit: Mathew Phillips
Surf photos courtesy of Mathew Phillips
The next day was spent with the science crew getting ready to bring aboard equipment they will be using, accessing and streamlining the information they need for the data collection, and also a little bit more shore time with fishing and hiking. I hiked up a local mountain called Pyramid.
Overall this has been a great start for a wonderful trip. I love to get my students outside experiencing the real world. After a year of taking both Oceanography and Marine Biology my students get to touch, see and smell the ocean through a field trip. They get to see marine birds and mammals, touch and taste icebergs and smell the brine scent of the ocean. They also get a chance to apply the knowledge and skills that they have learned in my class. The NOAA as Teacher at Sea Program is my field trip. I get to see the science and technology in action and share it with my students, friends and family. Thanks so much for letting me play!
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (in port, Kodiak Island): 57o 47.0200′ N, 152o 25.5543′ W
Date: June 22, 2023
TAS Laura Guertin and a pollock!
I’m wrapping up my time on NOAA Ship Oscar Dyson. There was so much that went in to getting out to sea for this expedition, and so many people that did so much work pulling for me and coordinating all the logistics before I joined Dyson (starting in 2020!), during my time at sea, and I’m sure after I leave the ship. Thank you to the wonderful people in the NOAA Teacher At Sea Office (Jennifer, Emily, Britta) and for giving me an opportunity to sail as a Teacher At Sea Alumna in 2023.
While waiting to board Oscar Dyson in 2022 during my first trip to Alaska, I prepared several blog posts that provided a background to NOAA, NOAA Fisheries, fisheries surveys, etc. With my undergraduate students in mind as my audience, I wanted to start the posts at the broadest scale and have the content easily utilized in multiple courses that I teach. As I authored these posts from Alaskan hotel rooms in 2022 and in 2023 and not while on the ship, they do not contain personal logs. Again, I thank the Teacher At Sea Program for giving me this flexibility in having one post that captures my personal log from the shortened expedition and keeping the “academic” focus for the prior content.
I’m trained as a geoscientist. During and after my studies in marine geology and geophysics, I’ve had the opportunity to participate in fieldwork in expeditions that have lasted hours to days to weeks to months. Although I think I know what it takes to live/work at sea, I’m reminded of new challenges on new ships in new ocean basins. It is so important as an educator that I take advantage of opportunities to get out to sea for my own professional development and to remind myself of what to share with students and community members when I present the story of what we did during our time at sea. I know I sound like a broken record – I’ve written these same words before. But that doesn’t mean these points are less important!
First topic of reflection – the people
This expedition had 32 people on board, which included the science party, bridge crew, stewards, engineering, deck, electronics technicians, and survey. The people on Oscar Dyson were born/raised and live in parts across the United States. Some people were sailing on a NOAA ship for the first time, and a few people were working for their first time on the ocean! We all have different backgrounds and training and personalities. In a way, I feel like stepping on to Oscar Dyson was like joining a game of Yahtzee – put all of these people together, shake us up (by sending us out to sea), and see what rolls out. Fortunately, during this “game”, everybody was a winner. On this 208.6-foot long ship, everyone has a purpose and function, and we must all work together to accomplish our research goals and the mission of the expedition. And to be successful, this group was supportive, understanding, respectful, took the time to listen, and made sure to laugh and smile through everything we faced.
Departing Kodiak aboard NOAA Ship OscarDyson
Next topic – the work
The schedule is very different than one I keep as an instructor. At home, I know the days/times I’m teaching, and I have a calendar to organize meetings and personal appointments. I’m pretty much in charge and in control of my own schedule. At sea, it’s not “me” but “we” when it comes to all day, each and every day. There are no weekends or holidays off. We work 12-hour shifts (mine was 4AM to 4PM) during the entire expedition. Once you leave your room at the start of your shift, you can’t go back to your room until your shift is over (you are sharing a room with someone that works a different shift than you, so the room is theirs during your work time).
But you are plenty busy during your 12 hours! There can be downtime as the ship transits to a site to begin data collection, and the weather can cause a change of plans for where you are headed and what work you can do. High winds, rainstorms, cold air temperatures, the ship rolling and heaving… we faced it all during our 13 days at sea.
And this work is hard! It is a balance of the physical demands faced by the deck crew setting the trawl net, and those working in the fish lab to furiously and accurately process the catch brought on board, and everyone ensuring that safety is a top priority at all times. The Chief Scientist working in the ship’s acoustics laboratory and all the NOAA Corps Officers working on the bridge must balance the scientific mission with the realities of our present situation – is there too much ship traffic to “go fishing” and set out the trawl net? Are there whales or other marine mammals in the vicinity? Is the wind speed too high for us to operate safely?
Everything on Oscar Dyson operates at a different pace and schedule from back home. Fortunately, we are able to balance out our time in the laboratories with taking short breaks to view beautiful sunrises and do some whale watching. Again, it is the amazing group of people on this ship, from the seasoned sailors to those doing fisheries work for the first time, that come together to mentor and support one another. They all make the work not seem like “work” but instead a really enjoyable and exciting time, knowing our efforts are making a difference for sustainable fisheries.
TAS Laura Guertin in the Gulf of Alaska
Final topic – what comes next
My time on Oscar Dyson has provided me an amazing opportunity and wealth of information about a field where I have had no training. Now that Leg 1 of the 2023 Summer Survey has wrapped up, I’m reminded of a popular saying from one of my graduate school faculty members – “so what?”
“So what?” stands for a family of questions or an attitude that leads to consideration of the broader significance of specific studies. These kinds of questions are particularly useful in descriptive research because, often, one can get so absorbed in collecting, organizing, and analyzing observations one forgets to consider the implications of the results. — Ginsburg (1982), Seeking Answers; suggestions for students
This “so what” piece is something I will spend even more time in the future thinking about. The “so what” of the survey is clear – NOAA does an excellent job explaining what sustainable fisheries are and why it matters (see my previous blog posts). But I still need to do a better job of figuring out how to connect the dots – the endpoints being what we do on the water (and the data we collect) to the production of the annual Status of Stocks and other products NOAA uses to inform the ecosystem management. The Magnuson-Stevens Fishery Conservation and Management Act, the primary law that governs marine fisheries management in federal waters, is also something I want to get up to speed on.
In addition, I need to think about defining the “so what” for the various audiences I will be sharing my at-sea experience. I have more NOAA resources to explore, such as The NOAA Fisheries Distribution Mapping and Analysis Portal (DisMAP) and The Fisheries One Stop Shop (FOSS) Public Data Portal. I will certainly be looking for other resources to pull in to my materials for students and presentations to the public, ranging from the Food and Agriculture Organization of the United Nations (FAO) to episodes of The Fisheries Podcast. I also look forward to exploring more resources on diversity and representation in fisheries science, with articles catching my eye: Women Leaders Are Essential for Tackling Ocean Sustainability Challenges (Fisheries Magazine, 2023) and Examining Diversity Inequities in Fisheries Science: A Call to Action (BioScience, 2016).
So my learning is not done! The sharing of my adventure and new knowledge is only beginning, and I look forward to sharing my pollock survey stories to not only positively impact the ocean literacy of my audiences, but to show how NOAA’s fishery work helps us address the Ocean Decade Challenges (part of the United Nations Decade of Ocean Science for Sustainable Development).
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (in port, Kodiak Island): 57o 47.0200′ N, 152o 25.5543′ W
Date: June 22, 2023
TAS Laura Guertin shows off her Teacher at Sea beanie aboard NOAA Ship OscarDyson
As we return to Kodiak, Alaska, for Leg 1 to wrap up and Leg 2 to begin of the 2023 Summer Survey, it’s exciting to know that even during our shortened expedition time at sea, we’ve collected data that is going to inform Alaska walleye pollock stock assessment models and catch allocation. Any/all data are good data to have! I have thoroughly enjoyed my time on Oscar Dyson and met some incredibly smart, passionate, kind, creative, and innovative people. The NOAA community is filled with amazing individuals that are not only dedicated to the NOAA science mission but then sharing that new knowledge with others. I’ve played a small part in this NOAA community during the expedition (while wearing my NOAA hat!), but I hope my future teaching and outreach efforts will shine an even brighter spotlight on the essential work carried out by NOAA Fisheries and the agency as a whole.
Prior to joining the ship, this past academic year was filled with some highs and lows in teaching and student learning. There’s one topic that I’m not quite sure how to classify – and that’s the emergence of Chat GPT, and how AI is being used in higher education. I was joking with the Instructional Designer at my campus (Penn State Brandywine) that I was going to write a sea shanty about this expedition. Turns out, he was able to get AI (Bing, specifically) to write one for me! So as I wrap up my time as a Teacher At Sea Alumna, I leave you with these versus to sing to your favorite shanty rhythm.
A Song of Pollock and Trawls
Oh we are the surveyors of the Gulf so vast and wide We sail the seas with acoustic gear to find the pollock hide We use sound waves to scan the depths and mark what we have found We measure their abundance and their biomass by the pound
(Chorus)
Yo ho ho as we sing this song On Leg 2 we’ll bring the DriX along Yo ho ho as we sing this song We love our job and we love our fish We love our job and we love our fish
We work in shifts around the clock to cover all the grounds We set the course and speed and time to trawl a certain length We haul the net and sort the catch and check their age and health We record all the data and we share it with the world
(Chorus)
We do this work for science and for management as well We help to keep the fishery sustainable and well We study the pollock’s life history, ecology, and stock We are proud to be part of this crew and this important work
(Chorus)
Oh we are the surveyors of the Gulf so vast and wide We sail the seas with acoustic gear to find the pollock hide We love our job and we love our fish We love our job and we love our fish
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, to Shumagin Islands area Location (10:45AM (Alaska Time), June 21): 55o 29.7525′ N, 156o 44.7276′ W
Data from 10:45AM (Alaska Time), June 21, 2023 Air Temperature: 8.4 oC Water Temperature (mid-hull): 8.2oC Wind Speed: 8 knots Wind Direction: 20 degrees Course Over Ground (COG): 76 degrees Speed Over Ground (SOG): 11 knots
Date: June 21, 2023
Once the echo sounder has shown us the position of an aggregation of Alaska walleye pollock (we hope they are pollock and not some other fish species), we lower the trawl net and see what we can catch. This is where the trawl sonar and CamTrawl (see previous blog post) come in handy to give us an idea of what is going into the net. It’s an amazing coordination of effort between the acoustics lab (who decides where to trawl), the bridge for navigation, and the deck crew for setting/retrieving the haul.
We aim for trawling at the mid-water level, where the pollock are typically found. Pacific Ocean perch (POP, or rockfish) can also be found in the mid-water level in the Gulf of Alaska, especially just off the shelf break. Bottom trawls can yield pollock and other fish (e.g., POP and other rockfish species, various species of flatfish).
Once the trawl net has been brought back on board, the catch is emptied into a bin called a table. There is a door on the side of the table that opens into the fish lab. Once the table door opens, the fish spill into the laboratory where they travel down a conveyor belt for the initial sorting. Our target species is the pollock. We weigh everything that ends up onto the sorting table, either in bulk (by species) or individually.
Pollock moving along the sorting belt
Pile of Pacific Ocean perch (rockfish) after being hauled on the ship
Small squid that fell out of the trawl net on deck.
A subset of around 250 pollock are set aside to collect length data. The length of these of each individual pollock are measured on an Ichthystick. This is another invention by Rick Towler and Kresimir Williams (remember the CamTrawl? (see previous blog post)). As described in their article An inexpensive millimeter-accuracy electronic length measuring board, these NOAA scientists describe using magnetic measuring technology that, to millimeter resolution, takes a measurement when you placed a magnet on a sensor that runs the length of the board. For our pollock measurements, we were looking to record the fork length, and a quick placement of the red magnet along the fish tail sends the data to a computer program called CLAMS (Catch Logger for Acoustic Midwater Surveys).
Bins of pollock waiting to be measured on the Ichthystick
Ichthystick logo with a pollock sketch
Computer end of Ichthystick, which digitally shows the value of fish length and is written to CLAMS
Sketch showing what is measured for the fork length of a fish. From Corvallis Forestry Research Community.
Pollock lying on Ichthystick getting its fork length being measured
Two scientists measuring pollock fork length on Ichthystick
Another subset of approximately 50 pollock are set aside for additional data collection on individual specimens – length, weight, sex, maturity, and age. Otoliths (e.g., ear bones) are removed, and sometimes organs are removed and measured (ovaries for maturity development analyses, liver).
Otolith pairs (two per individual fish) from an assortment of Bering Sea fish species. Walleye pollock is located in the top left. Note: otolith sizes are not on a relative scale. Photo: NOAA Fisheries.
What are otoliths, and why remove them? Otoliths are ear stones, or ear bones, found in fish. To give you an idea of why we remove ear bones, let’s start by thinking about trees and corals… trees grow a new ring on their structure each year, and corals have differences in their skeletal density between the seasons (both trees and corals are also used to reconstruct past climate conditions (proxy data for paleoclimatology)). By counting the rings on trees and coral, we can calculate the age of that specimen. It turns out that fish also have a way to record their annual growth – and it occurs in their ear through Fish Otolith Chronologies.
Scientists are very interested in studying otoliths. When otolith data are combined with data on fish size, scientists are able to determine the growth rates of fish, which then combined with the survey work, helps inform annual fish stock assessment reports. We don’t do any of the otolith analyses on the ship, but we do collect the samples with a detailed label and all the corresponding data (fish length, sex, weight, location) that is sent back to the NOAA Fisheries Alaska Fisheries Science Center for analyses and entered into their Fish Otolith Collection Database.
Rockfish otoliths
Zoom of rockfish otoliths
Otoliths still inside a pollock
Placing an otolith cleaned in freshwater into a vial for storage and shipment for analysis
Did you know… More than 30,000 otoliths are read annually by NOAA Fisheries Alaska Fisheries Science Center scientists. So far, the Science Center has collected more than 1.1 million fish otoliths for ageing. (from NOAA Fisheries)
To learn more about the fascinating studies of otoliths and what NOAA Fisheries is doing, check out these websites:
NOAA Fisheries Age and Growth – NOAA Fisheries scientists assess the age and growth rates of fish species and populations to better monitor, assess, and manage stocks. There is also a separate site for Age and Growth Research in Alaska.
NOAA Fisheries Near-Infrared Technology Identifies Fish Species From Otoliths – NOAA Fisheries scientists are developing ways to use near-infrared spectroscopy (NIRS) analysis of otoliths (fish ear stones) to provide accurate information for sustainable fisheries management faster.
If you are really curious to explore some fish otolith data, check out the Alaska Age And Growth Data Map, an interactive map displays collected specimen information from recent age and growth studies from Alaska Fisheries Science Center.
