“The joy of life comes from our encounters with new experiences, and hence there is no greater joy than to have an endlessly changing horizon, for each day to have a new and different sun.” — Jon Krakauer
Introduction
As I cram the last pair of socks, one more sweater and my field guide into my pack in preparation for my voyage on NOAA Ship Oscar Dyson next week, I think about how I got here and where I hope my journey helps to lead my students.
I was born a scientist, we all are; filled with questions and curiosity. As a child, I could often be found barefoot, traipsing about armed with a fishing net, a pair of binoculars, matches, a magnifying glass and the Little Golden Nature Guides. I grew up on an island and loved being out on the ocean and everything living within it. I took every biology class my high school offered because it meant weekly trips to the beach.
As a middle school teacher for over 30 years, my goal is to recreate not just that excitement of discovery, but the deep dive into problems when the answers don’t come easy. I encourage leaning into adventures and opportunities even when you feel out of your element or unsure of yourself. NOAA’s Teacher at Sea Program has given me just such an enterprise to lead by example, so come follow me on my great adventure.
Science and Technology Log
All great adventures involve a quest, so who are we searching for? Check out this legendary beast, this is the Alaskan pollock (Gadus chalcogrammus) aka the walleye pollock. That scientific name is like his code name: Gadus means “cod” and chalcogrammus “brass mark.” Check out his ID photo, see that golden brown line of spots, that’s our guy!
Pollock are a close relative of the cod fish we see here on the east coast. They typically grow to be between 12” – 20” in length and weigh from 1-3 lbs. It’s a fish eat fish world out there where, depending on their size and life stage, pollock eat everything from zooplankton to small fishes. In turn, pollock are a favorite meal for others including ocean mammals, such as sea lions, larger fish, sea birds and those of us who love a good Filet-O-Fish. Pollock, like middle schoolers, hang out with their buddies and family in large schools, spending their days on both the ocean bottom and the column of water above it. Although they live throughout the waters of the Pacific Ocean, the largest concentration of Alaskan pollock is in the Bering Sea, so that’s where we are headed. Up to the Alaskan coast starting out in the Aleutian Islands at Dutch Harbor.
Did You Know?
Alaskan pollock may seem new or unfamiliar to you but it has been hiding in plain sight all around you. Go on your own pollock hunt and see how many Bingo squares you can find in your home, school or community.
If you’re anything like me, you’ve never given the pollock (Gadus chalcogrammus) a second thought. However, the humble pollock, which occurs throughout the North Pacific Ocean and is especially common in Alaska, plays a linchpin role in the US seafood industry.
In 2024, pollock accounted for 43% of all seafood caught in the US by weight. That’s bigger than salmon, lobster, and tuna put together!
Clearly, pollock must be providing something of value; why is pollock such a large part of the harvest? Several factors contribute to pollock’s popularity with the fishing fleet.
1. Pollock are relatively easy to catch as they school densely in mid-water. Mid-water trawling can sometimes be much quicker and easier than other types of commercial fishing.
2. Pollock is a lean, lightly-flavored whitefish that can be used as whole cuts or processed into products such as surimi (artificial crab meat) and has been shown to be a good source of lean protein and Omega-3 fatty acids.
A comparison of the nutritional value of pollock to other dietary protein sources. – USDA
3. Pollock has a much smaller lifecycle carbon footprint than other protein sources. Due to the efficiency of mid-water trawling and industry innovations, you can hit your macros while leaving the carbon where it belongs, cycling through the ecosystem.
A comparison of the carbon impact of pollock vs other common animal protein sources.
Pollock sure sounds like a great, sustainable protein source, but let’s take a step back and meet the fish behind the stick!
An Adult Alaskan pollock (Gadus chalcogrammus)
Pollock are a member of the same genus as Atlantic and Pacific cod, and grow to around 20 inches on average over their 15-year lifespan. Their Latin name, chalcogrammus, is derived from the beautiful copper patterns that adorn their dorsal sides.
In winter, pollock move closer to shore, gathering in large schools to spawn. In summer, they migrate farther onto the continental shelf, forming more dispersed schools.
The Midwater Assessment and Conservation Engineering (MACE) Summer Pollock Acoustic Survey helps NOAA track and manage this vital economic and cultural resource by monitoring the location, size, and well-being of the eastern Bering Sea pollock population. This summer, the scientists have extended some of the acoustic transect lines northward to ensure the survey captures a more holistic picture of the population distribution in the eastern Bering Sea.
In this animation, lighter colors indicate a higher abundance of pollock at a given location. In 2010, AFSC bottom trawl data showed that the pollock population was concentrated at the far western edge of the study area. Conversely, in 2017, the population was much more evenly dispersed across the region. Observations like these help MACE scientists plan future work to better understand the extent and variability of pollock population distributions across the eastern Bering Sea. data source: FFSC eastern Bering sea bottom trawl survey from https://apps-st.fisheries.noaa.gov/dismap/index.html
Personal Log
As a guest of this crew, it has been great to get to know the science team, the NOAA Corps, and the crew that make Oscar Dyson run like a well-oiled machine. From Frankie in the mess (sooooo good), to the officers on the Bridge, it is evident that everyone WANTS to be here.
Wildlife sightings
🚨Charismatic Megafauna Alert🚨
A humpback whale stopped by on our way north from Dutch Harbor, AK.
Did You Know?
“For the 26th consecutive year, Dutch Harbor, Alaska, led the nation in seafood landed volume (780.1 million pounds, valued at $224.5 million).” (Fisheries of the United States 2023).
From the library
“The war between water and land is never-ending. Waves shatter themselves in spent fury against the rocky bulwarks of the coast; giant tides eat away the sand beaches and alter the entire contour of an island overnight…”
– Corey Ford, Where the Sea Breaks Its Back: The Epic Story of the Early Naturalist Georg Steller and the Russian Exploration of Alaska
NOAA Teacher at Sea Nick Lee Aboard NOAA Ship Oscar Dyson June 29 – July 20, 2024
Mission: Pollock Acoustic-Trawl Survey
Geographic Area of Cruise: Eastern Bering Sea
Date: July 21, 2024
Science and Technology Log:
When I applied to the Teacher at Sea program, I was hoping to use my experience on one of NOAA’s cruises to enhance my AP Environmental Science class. Now, having just completed my time aboard NOAA Ship Oscar Dyson, I’m looking forward to incorporating pollock and fisheries research into my existing curriculum. The scientists’ research involved concepts that are already a key part of the AP Environmental Science curriculum, like biodiversity, sustainable fishing, and ocean currents. I’m excited to engage my students this year with more real life examples and photos from the cruise!
View from the bridge on the last day of the cruise.
I wasn’t expecting to see as many applications of computer science on the cruise – however, I was surprised to learn how much of the scientists’ job on the ship involves coding and statistical analysis. At any given time, it seemed like at least one member of the science team was coding in Python or R, creating new programs and data visualizations that would help make their research more efficient and effective. We relied on many different computer applications to collect both acoustic and trawl data, almost all of which had been coded by the scientists and their colleagues.
MACE MasterApp, the suite of apps the scientists use to collect and analyze data.
Some of these programs didn’t even exist just a few months ago, but they were created when someone on the team recognized an area for improvement. This represents a broader mindset of adaptability and collaboration I noticed among scientists. On the ship, plans constantly changed in response to weather, delays, and equipment malfunctions. While these could be frustrating, the scientists always looked for ways to still complete their research, troubleshooting with each other and with the other ship departments.
The science team on my cruise. From left to right: Mike Levine, Robert Levine, Dave McGowan, Abigail McCarthy, Taina Honkalehto, Moses Lurbur, Sarah Stienessen, Matthew Phillips, Nick Lee (Photo Credit: Emily Resendez).
I also learned how the scientists had been adaptable in their own careers. Most of the scientists I had worked with had not intended to study pollock when they were younger, and some had not even planned on studying marine science. However, when interesting opportunities presented themselves, they took advantage, even when this meant learning about a new type of research or traveling to a new location. Having different academic backgrounds meant the scientists had different perspectives, and each was able to contribute their own ideas on how to improve the group’s research. On this particular cruise, scientists were testing out cameras and studying pollock behavior at night in the hopes of improving their data collection methods for future surveys.
Personal Log:
I just arrived back in Boston after a few long travel days – I took a small boat from the ship to Dutch Harbor, and then I flew to Anchorage, then Seattle, and then finally Boston.
From left to right: Small boat being lowered from the ship and an eagle warning sign in Dutch Harbor (Photo Credit: Abigail McCarthy).
I’m still processing my experience as a Teacher at Sea, but overwhelmingly I feel lucky to have spent three weeks aboard NOAA Ship Oscar Dyson and grateful to all of the people I met along the way.
The crew of the ship were all kind and welcoming, and I was able to learn about the other departments on board. I was able to tour the engineering department, and I learned how the ship makes its own freshwater by evaporating seawater. I shadowed the survey technicians as they deployed CTDs (conductivity, temperature, and depth sensor), and I touched water samples they had captured from the bottom of the ocean. During one trawl, I joined the deck crew, and I was able to witness how they safely manage nets containing thousands of pounds of pollock. Finally, I was able to learn about marine navigation from the NOAA Corps Officers, and I was even allowed to (briefly) drive the boat!
From left to right: Engineering control room, streaming the net with the deck crew (Photo Credit: Mike Levine), and learning to drive from NOAA Corps Officer Emily Resendez (Photo Credit: Savi Morales).
I want to thank all of the crew and officers of NOAA Ship Oscar Dyson for making the past three weeks such a meaningful experience, and I want to thank the science team for letting me contribute to their research and answering all of my questions (special thanks to Robert Levine for editing these blog posts)! Finally, I want to thank Emily Susko and the Teacher at Sea Program for supporting me throughout this entire process.
Did you know?
Applications for next season’s Teacher at Sea Program open in November – more info can be found here!
NOAA Teacher at Sea Nick Lee Aboard NOAA Ship Oscar Dyson June 29 – July 20, 2024
Mission: Pollock Acoustic-Trawl Survey
Geographic Area of Cruise: Eastern Bering Sea
Date: July 15, 2024
Weather Data from the Bridge:
Latitude: 59° 51.9 N
Longitude: 173° 53.5 W
Wind Speed: 11 knots
Air Temperature: 6.1° Celsius (42.9° Fahrenheit)
Science and Technology Log:
On my cruise, scientists take acoustic measurements along the length of each transect. To ensure that they are accurately estimating the abundance of pollock, they take steps to separate out any backscatter that they believe didn’t come from pollock.
Scientists then apply algorithms to the data in order to estimate pollock abundance over the entire survey area. First, they break up the transect into 0.5 nautical mile (NM) sections and record the average backscatter for that section. Specifically, scientists are interested in the areal density – the amount of backscatter per square nautical mile (NM2).
This data can be challenging to interpret, so one way the scientists represent it visually is with a stick plot over the survey area:
Acoustic backscatter from the 2022 pollock survey.
In this graphic, the transect lines are shown in black, and the density of acoustic backscatter for each 0.5 NM section is represented with a yellow stick. The longer the stick, the greater the density of backscatter at that location.
Scientists then use this data to perform calculations on the entire survey area, including the space in between transects. For each 0.5 NM section of transect, the acoustic density is extrapolated halfway to the next transect on either side.
In this diagram, the red line represents a 0.5 NM section of transect for which acoustic density is calculated. This acoustic density is then applied to the entire pink rectangle, which extends halfway to the next to the transect on either side.
By doing this process for every 0.5 NM section of transect studied, scientists are able to calculate values of acoustic density for the entire survey area.
Map of current survey area and transect lines (black), with boxes (purple) indicating the area over which data from each transect is extrapolated.
Getting from acoustic density to pollock abundance takes another set of calculations, this time making use of trawl data. The pollock caught in each trawl can vary drastically in terms of size – some trawls are mostly juveniles, some trawls are mostly adults, and some are an even mix of both. For a given location, scientists use data from the nearest geographic trawl to estimate the distribution of fish in that area.
In some trawls, the most fish were within 20-30 cm in length (above) while in others, most fish were over 40 cm in length (below).
Having trawl data is necessary to convert the acoustic data into fish abundance because small and large pollock do not reflect backscatter equally. Scientists have studied this, and they have created a relationship for the different backscatter reflected by different length pollock. Using the distribution of pollock in the nearest trawl, scientists are able to proportionally allocate the observed backscatter to pollock of different lengths.
As pollock length increases, backscatter also increases. (Equation from Lauffenburger et al., 2023. Mining previous acoustic surveys to improve walleye pollock (Gadus chalcogrammus) target strength estimates, ICES Journal of Marine Science, Volume 80, Issue 6, August 2023, Pages 1683–1696, https://doi.org/10.1093/icesjms/fsad094)
As an example, let’s simplify the two locations sampled in the graphs above. Suppose the first location had only 20 cm pollock, the second had only 40 cm pollock, and equal backscatter was observed at both sites. Scientists know that, all else being equal, 20 cm pollock produce less backscatter than 40 cm pollock. This means that in order to reflect the same backscatter, there must be a greater number of 20 cm pollock than 40 cm pollock.
By repeating a similar process for each geographic location, scientists are able to estimate the number of pollock in the entire survey area!
Personal Log
The sailing and many of the operations of NOAA Ship Oscar Dyson are done by NOAA Corps officers. I hadn’t heard of the NOAA Corps before sailing, but I’ve since learned that they play an important role in facilitating NOAA research.
To learn more about the experience of NOAA Corps officers, I interviewed Ensign Savi Morales.
Ensign Savi Morales (left) on the bridge collaborating with John Swenson, a member of the deck crew.
Why did you decide to become a NOAA Corps officer?
I’ve always wanted to support the protection of the environment and mitigating climate change. After college, I was trying to figure out where I would contribute the most. I really loved being out on the water, and I had sailed plenty but I wanted to find a way to combine my interests in an environment I contribute the most. The NOAA Corps felt like it was a combination of those things.
I also loved the idea of working with the crew, engineering department, and science. I really enjoy that mixture of groups we have aboard Dyson, which makes every trip’s dynamic different. There’s also a lot of hands-on experience on the bridge deck making our 12 days packed with projects I work on. The NOAA Corps embraces a diverse skill set in order to think and act like a Swiss army knife and be a jack of all trades.
What are your responsibilities on board the ship?
My responsibilities are two 4-hour bridge watches as a Junior Officer of the Deck as I work towards becoming a fully qualified Officer of the Deck. In between my watches I work on tasks related to my responsibilities as the Dyson’s damage control officer, assistant navigation officer, and assistant public affairs officer. I track the sea service hours for our augmenting and personal crew, which they can use to upgrade their license. I maintain flags, and I do monthly safety rounds, inspecting fire extinguishers and fire stations.
What do you enjoy the most about your work?
I enjoy meeting the characters that come to the Dyson, definitely an eclectic but fun group. I also enjoy how much they’ve thrown me into the mix and had me figure things out. It’s a little bit of a trial by fire, but I learn really quick and I’d rather learn by doing.
What part of your job with NOAA did you least expect to be doing?
Checking fire extinguishers, there’s about 100 on board and they all need to be checked monthly. It takes about 3-4 hours.
Here in the Bering Sea you hear about the big, massive waves, but it’s not always like that. The Aleutian Islands are gorgeous with lots of wildlife. I don’t think I’ve seen this many bald eagles, orcas, or puffins in my entire life. They always brighten my day.
What advice do you have for a young person interested in a career in the NOAA Corps?
NOAA Corps requires you to have a four-year college degree in order to apply. Other than that, I’d say find opportunities to go out on the water. There’s high school scholarships, there’s college scholarships. You can also volunteer if you have time. I volunteered at the UC Davis Bodega marine lab. I visited once a week just to hang out with the scientists, with the crew to see if this is what I liked. Be curious and experience things for yourself!
Did you know?
NOAA Corps is one of the country’s eight uniformed services, and its officers operate NOAA ships and aircraft around the country. After completing basic training at the US Coast Guard Academy, NOAA officers assist in fisheries research, seafloor mapping, monitoring atmospheric conditions, and may respond to natural disasters and extreme weather. Learn more at the NOAA Corps website here!
NOAA Teacher at Sea Nick Lee Aboard NOAA Ship Oscar Dyson June 29 – July 20, 2024
Mission: Pollock Acoustic-Trawl Survey
Geographic Area of Cruise: Eastern Bering Sea
Date: July 6, 2024
Weather Data from the Bridge:
Latitude: 61° 15.0 N
Longitude: 174° 56.8 W
Wind Speed: 13 knots
Air Temperature: 5.3° Celsius (41.5° F)
Science and Technology Log:
On NOAA Ship Oscar Dyson, the science party’s mission is to understand the population of walleye pollock in the Eastern Bering Sea. To collect data, scientists rely on two main tools: acoustics and targeted trawling. Before any trawling can happen, scientists must first locate fish using acoustics, so I’ll be focusing on acoustics in this blog post – stay tuned for a post on trawling next time!
Scientists use two kinds of acoustics: active and passive. Many of my students are familiar with how bats use echolocation to navigate in the dark – active acoustics relies on the same principle. First, the echosounder on the ship emits a pulse of sound, or ping. This sound travels through the water and bounces off of objects that have different densities than water (such as fish, krill, or the ocean floor). The echosounder then “listens” for and records these echoes, also known as backscatter. Passive acoustics work similarly, except the echo sounder only listens for sound and doesn’t emit any itself.
The echosounder emits a pulse of sound, which gets reflected by objects of different densities, like pollock.Image Credit: Wieczorek, Schadeberg, Reid (2021) “How do Scientists Use Sound to Count Fish in The Deep Sea?” Frontiers for Young Minds. https://kids.frontiersin.org/articles/10.3389/frym.2021.598169
The greater the distance between the echo sounder and the object reflecting the pulse, the greater the amount of time between when the signal was emitted and backscatter. Based on this time, echosounder can determine the depth of the object producing the backscatter. This information is represented visually in an echogram:
Screenshot of an echogram. The space between vertical grid lines represents 100 pings, and the space between horizontal grid lines represents 10 meters of depth.
The echogram shows depth on the y-axis and time on the x-axis. The intensity of backscatter is color-coded, where more intense backscatter is represented with red and brown, and less intense backscatter is represented with blue and green. The vertical grid lines represent all the backscatter from one ping, and the space between lines represent 100 pings.
On the cruise, pings are typically emitted at a rate of 1 Hz, or once every second. With every new ping, the echo sounder adds data to the right end of the echogram. This means that the horizontal grid lines represent the backscatter at one depth over time (or distance, if the ship is traveling at a constant speed).
At least one scientist monitors the backscatter throughout the duration of the transect. During the first day, the echogram was blank except for some lower-intensity backscatter near the surface and high-intensity reflection from the ocean floor. Because the mission of this cruise is to survey pollock, which tend to live at greater depths, we don’t pay much attention to the backscatter near the surface which is comprised of smaller organisms like krill. However, when scientists notice backscatter consistent with scattering from pollock, they may trawl to collect a sample for more detailed biological information.
Echograms from two different locations showing low-intensity backscatter (left) and high-intensity backscatter (right). When the backscatter looks as it does on the right, the science team may decide to fish in that area.
As we traveled along the first transect line, there was very little backscatter that the science team thought represented pollock. Our CTD (conductivity, temperature, depth) measurements also showed that the water temperature was cold, right around freezing. This may suggest that we were traveling through the Bering Sea cold pool, a mass of cold water that forms from melting ice. This water tends to be too cold for pollock and other fishes, however, other animals, such as snow crabs, can still survive the lower temperatures. Fish like cod prey on snow crab, so the cold pool offers these crab an important refuge from predators. Read more about the importance of the cold pool for crab here!
Historical bottom temperature showing cold pool in blue / purple (Image Credit: NOAA Fisheries)
Personal Log:
The start of the cruise has been busy learning new faces, maritime practices, and scientific terms. However, in the past few days, with the help of meclizine (seasickness medication), I’ve begun to feel more settled and like I have some sense of routine.
When I’m on shift, I bounce around between a few different places. The science team tends to be in the acoustics lab, where we monitor backscatter and make decisions on when to fish.
Acoustics lab, also called “the cave” for its lack of windows.
Once the scientists decide to fish, we first go up to the bridge, where NOAA officers control the direction and speed of the ship. The bridge has windows on all sides, so we’re able to make sure there are no marine mammals before putting the net in the water.
From the bridge, you can also see the trawl deck, where the deck crew works in collaboration with NOAA officers to put the net in the water. Once the fish are caught and hauled back to the ship, the science team processes the catch in the fish lab.
The bridge and its view of the trawl deck.
When we’re not working, we’ll grab food from the galley / mess deck. The stewards on the ship serve three meals a day, but since I’m on the night shift, I often heat up leftovers or take advantage of the wide selection of snacks they leave out. There’s also a lounge, two gyms, and places to do laundry while at sea!
The galley, where food is available 24 hours a day!
Did you know?
NOAA Ship Oscar Dyson has six onboard laboratories including a wet lab, dry lab, electronics lab, bio lab, acoustics lab, and hydrographics lab. Read more about the ship here!
