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: 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.
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 (2PM (Alaska Time), June 19): 55o 30.9384′ N, 159o 47.6478′ W
Data from 2PM (Alaska Time), June 19, 2023 Air Temperature: 8.2 oC Water Temperature (mid-hull): 6.8oC Wind Speed: 18 knots Wind Direction: 62 degrees Course Over Ground (COG): 30 degrees Speed Over Ground (SOG): 11 knots
Date: June 20, 2023
To conduct a fisheries survey or any oceanographic research expedition, there’s an enormous checklist of items you need on a ship. Jokingly, those on board will tell you that food and internet access are at the top of the list. But there’s no doubt that technology and its function, application, durability, etc., are critical during the time at sea. For example, see NOAA’s explainers for Ocean Exploration Technology: How Robots Are Uncovering the Mysteries of the Deep and Collecting and Visualizing Deep-Sea Data. For a broader look at the technologies NOAA uses to explore the ocean (vessels and submersibles, observing systems and sensors, communication technologies, and diving technologies), see Exploration Tools.
Leg 2 of this Summer Survey will be bringing on board the DriX, an uncrewed surface vehicle (USV), to see if this technology can improve the efficiency of collecting acoustic and biological data to estimate pollock abundance when working alongside Oscar Dyson. To read more/see a video, check out NOAA’s article, Uncrewed Surface Vehicles Complement NOAA Vessels for More Efficient Fisheries Surveys.
Trawl Sonar
The Simrad FS70 on the back deck of Oscar Dyson (June 2023)
Trawl sonar units are used to provide a rough estimate of how many fish are going into the trawl net. The device (which we’ve been using on our expedition, a Simrad FS70 nicknamed “the turtle”) is a third wire system that in real time establishes communication between the submerged sonar head and the bridge. On this cruise, the trawl sonar unit is placed on the headrope of the trawl net (i.e., on the top of the mouth of the net). It communicates its depth back to the ship. It also scans the mouth of the net and relays any acoustic images of things going into the net back to the ship. These data allow the scientists and crew to adjust the depth of the net and length of time the trawl net remains in the water to collect samples. Our goal is to collect enough fish (approximately one ton) to have a representative sample of the various species and lengths of fishes in the water column.
Screenshot of the display returned by the FS70 during a trawl. The pink/yellow/blue line in the left column is where you see the bottom of the net. This is also represented in the middle column by the multi-colored horizontal line you see in the third circle from the center. (Screenshot from Leg 1 provided by Rick Towler).
One fascinating piece of technology we’re using on this pollock survey is the CamTrawl. This article I found will give you everything you would want to know about CamTrawl in a non-technical summary:
Introduced in 2012, the CamTrawl is a stereo camera system when attached to a trawl net, can provide data about fish without ever touching a fish. This 3D imagery records fish passing by the camera towards the codend (the closed end of the trawl net), which provides species and size composition data as well as how fish behave in the trawl net to be collected from within a midwater survey trawl. CamTrawl is used to verify the trawl catch and specimen data, and in some cases, can be used to determine where in the water column the species entered the net. These data help inform ecosystem-based fisheries management.
The CamTrawl on Oscar Dyson for 2023 Summer Survey. The orange balls are flotation devices, the two “eyes” in the middle are the stereo camera and computer system, with the battery power across/under the eyes. The four round devices in the corner are lights used during the image recording.
Top-down view of the CamTrawl. The front of the camera set-up is the wider side of the trapezoidal frame (top of image) which is then attached to the trawl net.
Figure 1 from Williams et al. (2016). CamTrawl system description.
CamTrawl attached to trawl net about to be set off the back of Oscar Dyson.
The CamTrawl has uses and applications beyond our walleye pollock survey. It can go to depths of the ocean where it is not possible to lower a trawl net and capture data on other fish species like the bottom-dwelling rockfish. CamTrawl can explore and map deep-sea corals, and there is potential for collaborative research with the fishing industry.
Some CamTrawl footage from Leg 1 of 2023 Summer Survey.
The CamTrawl was developed by NOAA scientists Kresimir Williams and Rick Towler (both of whom I’m sailing with on Oscar Dyson for Leg 1). I feel incredibly fortunate to have sailed with these two scientists and to hear how NOAA encourages their researchers to be creative and experiment with developing technologies to advance NOAA’s overall mission and expedition objectives.
CamTrawl being detached from a trawl net after a mid-water trawl (June 16, 2023, on Oscar Dyson)
Curious to see more? Check out this Salmon shark caught on CamTrawl underwater camera.Below is a picture of a salmon shark from the Shumagin Islands, Alaska area in February 2017 (photo provided by Sarah Stienessen).
Boldt et al. (2018). Development of stereo camera methodologies to improve pelagic fish biomass estimates and inform ecosystem management in marine waters. Fisheries Research, 198. https://doi.org/10.1016/j.fishres.2017.10.013
Williams et al. (2018). A method for computing volumetric fish density using stereo cameras. Journal of Experimental Marine Biology and Ecology, 508. https://doi.org/10.1016/j.jembe.2018.08.001
Williams et al. (2016). Automated measurements of fish within a trawl using stereo images from a Camera-Trawl device (CamTrawl). Methods in Oceanography, 17. https://doi.org/10.1016/j.mio.2016.09.008
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 (2PM (Alaska Time), June 18): 55o 15.3391′ N, 160o 17.8682′ W
Data from 2PM (Alaska Time), June 18, 2023 Air Temperature: 8.9 oC Water Temperature (mid-hull): 7.7oC Wind Speed: 4 knots Wind Direction: 182 degrees Course Over Ground (COG): 356 degrees Speed Over Ground (SOG): 12 knots
Date: June 19, 2023
Acoustic fisheries surveys seek to estimate the abundance and distribution of fish in a particular area of the ocean. In my case, this Summer Survey is looking at walleye pollock in the Gulf of Alaska. How is this accomplished? Well, it’s not through this method:
The Alaska walleye pollock is widely distributed in the North Pacific Ocean with the largest concentrations in the eastern Bering Sea. For this expedition, Oscar Dyson is traveling to specific regions in the Gulf of Alaska and running transects perpendicular to the bathymetry/contours (which are not always perpendicular to the shore) to take measurements using acoustics and targeted trawling to determine the abundance and distribution of walleye pollock which informs stock assessment and management models. For this blog post, let’s focus on how and why we can use acoustics to locate fish.
Walleye pollock (Gadus chalcogrammus) are distributed broadly in the North Pacific Ocean and eastern and western Bering Sea. In the Gulf of Alaska, pollock are considered as a single stock separate from those in the Bering Sea and Aleutian Islands. Image from Alaska Department of Fish and Game.An snapshot of a nautical chart with transects plotted. The first transect was run during Leg 1 on June 14 at the furthest location to the west, then the ship worked its way back east with approximately 40 nautical miles between transects. Once Oscar Dyson reached the Shumagin Islands, survey work shifted into this area..
Our story starts with the fish itself. Alaska walleye pollock have a swim bladder. The swim bladder is an internal organ filled with gas that allows a fish to maintain its buoyancy and stability at depth.
One interesting effect of the swim bladder is that it also functions as a resonating chamber that can produce and receive sound through sonar technology. This connection was first discovered in the 1970s, when low-frequency sound waves in the ocean come in contact with swim bladders and they resonated much like a tuning fork and return a strong echo (see WHOI’s Listening for Telltale Echoes from Fish).
Internal anatomy of a boney fish. From Wikipedia (CC BY-SA 3.0).
The sound pulses travel down into the water column, illustrated by the white cones here, and bounce back when encountering resistance.(from NOAA Fisheries)
NOAA Fisheries uses echo sounding, which works by emitting vertical pulses of sound (often referred to as pings), and measuring the return strength and recording the time for the signal to leave and then return. Anything having a different density from the surrounding water (in our case – fish, plankton, air bubbles, the seafloor) can return a signal, or “echo”.
The strength or loudness of the echo is affected by how strongly different ocean elements reflect sound and how far away the source of the element is. The seafloor usually makes the strongest echo because it is composed of rock which has a density different than the density of water. In fish, the swim bladder provides a contrast from the water. In addition, each fish species has a unique target strength or amount of sound reflected to the receiver. The size and shape of the swim bladder influence the target strength. There is a different target strength to length relationship for each species of fish – the larger the fish, the greater the strength of the returning echo.
It’s important to note that echo sounders cannot identify fish species, directly or indirectly. The only way we know which fish species is causing a signal is based on trawl catch composition. There is nothing within the acoustic data that lets us identify fish species, even with the catch data. This is a subtle, but important, distinction. Acoustic data, particularly calibrated acoustic data, in tandem with the information from the trawl, definitely allows us to count fish.
Where is the echo sounder on Oscar Dyson? Look at the figure in the next section of this post – it’s a sketch of NOAA Ship Rainier, but the placement of the echo sounder is the same for Dyson. You can see a rectangular “board” that is extended down from the center of the ship. This is called – what else – the center board! Attached to the bottom of the center board are the echo sounders. When lowered, the echo sounders sit at 9 meters below the level of the sea (~4 meters below the bottom hull of the ship).
Did you know… Southern Resident killer whales use their own echolocation clicks to recognize the size and orientation of a Chinook’s swim bladder? Researchers report that the echo structure of the swim bladders from similar length but different species of salmon were different and probably recognizable by foraging killer whales. (reported in Au et al., 2010)
It starts with a calibration
Typical setup of the standard target and weight beneath the echo sounder.(from NOAA Fisheries)
Before we can begin collecting data, we need to calibrate the echo sounder. The calibration involves a standard target (a tungsten carbide sphere) with a known target strength. The calibration needs to be completed in waters that are calm and without significant marine life for the best results.
The sphere is suspended below the ship’s hull using monofilament lines fed through downriggers attached to ship railings. One downrigger is in line with the echo sounder on the starboard side, and the other two on the port side. This creates a triangle that suspends the sphere in the center of the echo sounder’s sound beam. By tightening and loosening the lines, the sphere can be positioned under the center of the sound beam and can also be moved throughout the beam. By doing an equipment calibration at the beginning and end of a survey, we can ensure the accuracy of our data.
One of the port side downriggers
A weight that goes at the bottom of the filament to ensure the calibration sphere remains below the echo sounder
The tungsten carbide sphere attached to the line, being lowered over the side
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, Western Gulf of Alaska Location (2PM (Alaska Time), June 15): 53o 38.9534′ N, 166o 10.9927′ W
Data from 2PM (Alaska Time), June 15, 2023 Air Temperature: 8.74 oC Water Temperature (mid-hull): 6.2oC Wind Speed: 3.55 knots Wind Direction: 310.61 degrees Course Over Ground (COG): 64.09 degrees Speed Over Ground (SOG): 11.61 knots
And now, it’s time for some science and surveying! Before I dive into the specifics of the methods we are carrying out on Oscar Dyson, I’m sharing this incredibly helpful NOAA Fisheries page that summarizes their Research Surveys, where “Our scientists and partners collect data on the water, from aircrafts, and from shore to understand the abundance, distribution, and health of marine life and habitats. That data forms the scientific foundation for our management and conservation work.”
There is also an informative podcast episode, Learn About NOAA Fisheries Surveys (transcript available at link). This podcast covers the need for sustainable fisheries, the 2013-2016 North Pacific Blob, how surveys were done historically, how surveys are using new technology, the impact of the pandemic, and the concept of being in a “stationary” versus “non-stationary” world. Such a fascinating listen!
First episode of “Dive In with NOAA Fisheries,” titled Learn About NOAA Fisheries Surveys
There is another podcast episode from the same series that is an excellent follow-on from the episode available above. Surveying Alaska’s Waters (transcript available at link) shares how surveys are a tools that allow NOAA to reach its mission, whether those measurement techniques come from satellites, autonomous vehicles, buoys, ships, drones, etc. Although these tools assist NOAA scientists in collecting data, climate change is playing an even bigger role in making ecosystem management a moving target. Again – worth a listen!
Third episode of “Dive In with NOAA Fisheries,” titled Surveying Alaska’s Waters
Surveys in the Gulf of Alaska
Trawl surveys have been conducted by Alaska Fisheries Science Center (AFSC) beginning in 1984 to assess the abundance of groundfish in the Gulf of Alaska (2021 Stock Assessment Report, p. 9). Starting in 2001, the survey frequency was increased from once every three years to once every two years on odd-numbered years. This is a flyer that describes the biennial bottom trawl survey in the Gulf of Alaska 2023.
The strategy of combining trawl and acoustic surveys was developed by AFSC and the University of Washington. They published a paper in the Canadian Journal of Fisheries and Aquatic Sciences (Kotwicki et al., 2018) that discusses the need to perform acoustic-trawl (AT) and bottom-trawl (BT) surveys to accurately estimate the abundance of fish populations along with their spatial distribution. I’ve provided below part of a news release from the University of Washington describing the content of the publication:
Many species of fish spend some of the time on the ocean bottom, and some of their time far off the bottom, which makes them hard to survey. Acoustic surveys (that bounce sound off fish schools), can estimate the midwater component of so-called “semipelagic” fish, while trawl surveys can measure the portion on the bottom. Now a new method has been developed that combines data from both types of surveys into a single estimate using information about the environment (bottom light, temperature, sand type, and fish size). The new method has been used to assess the status of walleye pollock, which sustains the largest fishery in the United States.
This image from Kotwicki et al., 2018, does an excellent job of showing the two types of survey methods, acoustic and bottom trawling.
Fig. 1. Illustration of conceptual model of walleye pollock sampling by an echo sounder and a bottom trawl. Note that acoustic data are collected directly under the survey vessel, while the bottom trawl catches walleye pollock some distance behind the vessel. Diving occurs in the time between the vessel passing over the school of walleye pollock and the trawl catching the same school. Source: Kotwicki et al. 2018.
What is different for my current expedition is that we are not doing any bottom trawling. We are doing the acoustic piece of the survey and trawling off the bottom. Separate surveys and ships are collecting the bottom data, and then will be combined with our data to provide a more accurate snapshot for the water column for the annual Stock Assessment Report for Walleye Pollock. AT and BT surveys get NOAA to their research objective: informing fish stock assessment models and catch allocation. NOAA publishes an annual 100+page Assessment of the Walleye Pollock Stock in the Gulf of Alaska from the surveys conducted each year (see reports from 2019, 2020, 2021).
To prepare to sail on Leg 1 of the Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska, I did a lot of reading and preparation so I could better understand what I would be learning, and how I could then connect the material with my students and additional audiences I see post-expedition. These two books in the image below helped give me a much better picture of not only walleye pollock but the fisheries industry, policy, and practices over time and space.
Each of these books provides some fascinating insight into the history, thought, and even debates, about the nature of ocean resources.
The title of Chapter 4 in Kurlansky’s book gives a hint for how to respond to my questions: “Being The Myth of Nature’s Bounty And How Scientists Got It Wrong For Many Years.” Early in the chapter, Kurlansky states:
“In the 1800s, when the study of fish and oceans was a relatively new science, it was the fishermen who were afraid that fish populations could be destroyed by catching too many fish, especially small fish. Scientists at the time believed that it was impossible to catch too many fish because fish produced so many eggs.” — World Without Fish, p. 53
One of the causes of concern for fishermen was the new technology developing – specifically, engine power, that allowed for even more fish to be caught.
“I believe that it may be affirmed with confidence that, in relation to our present modes of fishing, a number of the most important sea fisheries… are inexhaustible… and probably all the great sea-fisheries, are inexhaustible; that is to say that nothing we do seriously affects the number of fish. And any attempt to regulate these fisheries seems consequently… to be useless.” (*feel free to dive into Huxley’s speech to see his reasoning – the multitudes of fish available, and the destruction is minimal)
Then Lankester gave the final summary speech of the Exhibition – a rebuttal to Huxley. Lankester made the point that the fish in the sea are not unlimited, and captured fish are not readily replaced by others that exist further offshore from the fishing location. He raised the concern that the removal of the parents by fishing was going to impact the production of the young.
Although at the time many gave Huxley the victory in this debate, Huxley did not take into account the new development that I mentioned above – the modern trawl and the steam trawler to pull it, resulting in larger nets and catches. It’s interesting to note that eventually, Huxley studied the impact from engine-driven net draggers and changed his story. Huxley eventually agreed that overfishing was not only possible, but that it was happening.
Now to circle back to why we survey fisheries… it ultimately comes down to ecosystem management. As described in the two audio files at the top of this blog post and in my other posts, as well as the title to Chapter 8 in Kurlansky’s book, “The Best Solution To Overfishing: Sustainable Fishing.” And to engage in sustainable fishing, you need the data to make that happen – hence, fisheries surveys!
Mission: 2023 Summer Acoustic-Trawl Survey of Walleye Pollock in the Gulf of Alaska
Geographic Area of Cruise: Islands of Four Mountains area, Western Gulf of Alaska Location (2PM (Alaska Time), June 14): 52o 30.9860′ N, 169o 08.0942′ W
Data from 2PM (Alaska Time), June 14, 2023 Air Temperature: 8.11 oC Water Temperature (mid-hull): 8.0oC Wind Speed: 8.27 knots Wind Direction: 243.96 degrees Course Over Ground (COG): 239.25 degrees Speed Over Ground (SOG): 13.05 knots
Date: June 15, 2023
I’m trained as a geologist and oceanographer. My teaching and research has focused on the physical sciences, which is why I’m so excited to have the opportunity to work with scientists in the life sciences. But before I start with the acoustic-trawl survey of walleye pollock, I had to do my homework – namely, learn something about this fish!
There is a wealth of resources on NOAA’s website that are providing me the introductory overview or “101” on pollock and the overall mission of maintaining sustainable fisheries. I started by viewing this NOAA video on Alaska’s Pollock Fishery: A Model of Sustainability.
This video shared so much but also generated so many more questions! I decided to take a step back and do a deeper dive into some of these topics, starting with the fish…
Alaska (walleye) pollock
Alaska pollock (Gadus chalcogrammus) on the sorting table, from NOAA Photo Library
NOAA Fisheries is doing an incredible volume of work in the Alaska region – including a focus on the Alaska pollock.
A member of the cod family, Alaska pollock (Gadus chalcogrammus) is also referred to as pollock, walleye pollock, and Pacific pollock. The NOAA Fisheries Species Directory for Alaska pollock states that Alaska pollock typically grow between 12 and 20 inches and weigh between 1 to 3 pounds. Their speckled coloring allows them to blend in with the seafloor to avoid predators such as Stellar sea lions, fish, seabirds – even older pollock will feed on juvenile pollock! Humans feed on pollock in products from fillets to fish sticks to surimi.
Alaska pollock are found throughout the North Pacific Ocean but are most common in the Bering Sea. Pollock migrate inshore to shallow water to breed and feed in the spring, then move back to warmer, deeper waters in the winter.
The word “fishery” is used in many ways. It can refer to the occupation, industry, or season for catching fish. It can also refer to the area of ocean where fish are caught, or the business of catching the fish. U.S. fisheries include commercial (catching/marketing fish and shellfish for profit), recreational (fishing for sport/pleasure), and subsistence (fishing for personal/family/community consumption or sharing.
Next, what is meant by sustainable fisheries? NOAA defines this in the following video and in the quote below:
“U.S. fisheries are big business, providing jobs and recreation and keeping our coastal communities vibrant. In fact, the United States is a global leader in responsibly managed fisheries and sustainable seafood. Working closely with commercial, recreational, and small-scale tribal fishermen, we have rebuilt numerous fish stocks and managed to create some of the most sustainably managed fisheries in the world. U.S. fisheries are scientifically monitored, regionally managed, and legally enforced under 10 national standards of sustainability. Managing sustainable fisheries is a dynamic process that requires constant and routine attention to new scientific information that can guide management actions.” — from NOAA Fisheries – Sustainable Fisheries
NOAA’s FishWatch website is a great place to find the most up-to-date information on popular seafood harvested or farmed in the United States. This helps each of us as consumers to make smart choices! Check out the page for the Alaska pollock to see the details available for this fish, currently classified as a smart seafood choice because it is “sustainably managed and responsibly harvested under U.S. regulations.” This is so important to note, as according to FishWatch, the Alaska pollock fishery is one of the most valuable in the world, with commercial landings of Alaska pollock from the Bering Sea and Gulf of Alaska in 2020 totaling more than 3.23 billion pounds and were valued at approximately $420 million.
Alaska pollock library of articles
Several articles on NOAA’s website were helpful in not only providing me more background information to prepare for my time on Oscar Dyson, but the content really showed me the context of what NOAA is doing for fisheries research/management and why it matters. My students probably recognize this as a list of articles I would give them to develop their current event literacy, as these are recent dates of publication and from a credible source (NOAA, of course!) – and of course, contribute to advancing their ocean literacy.
If you wish to learn more about the current state of Alaska pollock research with NOAA, I highly recommend these recent articles from NOAA Fisheries News & Announcements:
For podcast fans, this 2013 NOAA Fisheries podcast episode titled Keeping an Eye on Pollock is an excellent overview of how “scientists and fishermen work together to understand how walleye pollock respond to a changing environment” (transcript available online).
NOAA Fisheries podcast, Keeping an Eye on Pollock
In reviewing these articles and the podcast, it is clear that NOAA is focused on advancing the technology to survey Alaska pollock with new tools such as saildrones. There is also an interest in closely monitoring the impact climate change is having on the juvenile and adult populations of pollock (see the NOAA Fisheries site on Climate Change). This video, released January 2022, is a great snapshot of how NOAA Fisheries is preparing and responding to the impacts of climate change (link to web page that supports the video).
OK, I’m feeling good about my background on the “what” and “why” of Alaska pollock, and I hope you are, too! Next, it’s time to share the activities of the science team that is applying science knowledge and technology tools to studying pollock on Oscar Dyson!
