One or many? Exploring the population groups of the largest animal on Earth

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Hunted nearly to extinction during 20th century whaling, the world’s largest animal, the Antarctic blue whale, went from a population size of roughly 200,000 to little more than 300. The most recent abundance estimate in 2004 put Antarctic blue whales at less than 1% of their pre-whaling levels.

But is this population recovering? Is there just one population of Antarctic blue whales, or multiple? Why do these questions matter for conservation?

Zoe Rand, a PhD student in the UW Quantitative Ecology & Resource Management program (QERM), is tackling these questions in a new study, published in Endangered Species Research on November 14, 2024. Building on the last assessment of Antarctic blue whales in 2004, and using old whaling records which were surprisingly detailed, Zoe has been investigating if there are different populations or one big circumpolar population. Also involved in the study is UW School of Aquatic and Fishery Sciences (SAFS) Professor and Faculty for the QERM Program, Trevor Branch, and Jennifer Jackson from the British Antarctic Survey.

Paula Olson
Antarctic blue whales are the world’s largest animal, and are still recovering from being hunted nearly to extinction during 20th century whaling.

Antarctic blue whales are listed as an endangered species, and understanding their population structure is essential for their conservation. Conservation at the population-level increases biodiversity, and this diversity helps the species adapt better to environmental changes and increases chances of long-term survival.

During the whaling years, biologists began the Discovery marking program. Foot-long metal rods with serial numbers were shot into the muscles of whales. When these whales were caught, the metal rod was returned, and information about the whale’s size, sex, length, and where they were caught, was collected. Looking at where whales were marked compared to where they were caught can shed valuable insight into the movement of Antarctic blue whales, but this data has never been used before to look at population structure.

International Whaling Commission
Historical mark that was placed in the muscles of whales and then recovered during whaling.

In this new study, this historical data was used alongside contemporary survey data in Bayesian models to calculate inter-annual movement rates among the three ocean basins that make up the Southern Ocean (Atlantic, Indian, Pacific), which are the feeding grounds for Antarctic blue whales. They found frequent mixing among the ocean basins, suggesting that whales do not return to the same basin every year. This points to Antarctic blue whales being one single circumpolar population in the Southern Ocean.

These results are consistent with evidence from Antarctic blue whale songs, heard throughout the Southern Ocean. Only one song type has been recorded amongst the Antarctic blue whales. In comparison, pygmy blue whales have five different songs corresponding to five different populations. These results are also consistent with genetic studies which found that Antarctic blue whales are similar genetically.

Paula Olson
Antarctic blue whales are listed as an endangered species, and understanding their population structure is essential for their conservation.

This is the first time that historical mark-recovery data from the Discovery marking program has been analyzed using modern quantitative methods. This data exists for many other hunted whale species, such as fin and sei whales, so it could provide a framework for similar analyses for those whale species too.

There is still a lot we don’t know about the Antarctic blue whale. Acoustic data and their movement on the feeding grounds, suggests there is just one population in the Southern Ocean. Even though they do not appear to be separated geographically on their feeding grounds, they could still have population structure because of differences in breeding habitats or the timing of migration. However, almost nothing is known about Antarctic blue whale breeding behavior. Using historical data from whaling alongside contemporary data such as satellite tagging, and photo-identification is our best hope for uncovering the secrets of the largest animal on earth.

Wetland Ecosystem Team working with Long Live the Kings on habitat restoration project

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In a new blog by Long Live the Kings, they explore the preliminary findings of post-restoration monitoring undertaken by the UW Wetland Ecosystem Team at a habitat restoration project at Vigor Shipyards, which was completed in the Spring of 2023.

Long Live the Kings + Wetland Ecosystem Team
Preliminary data shows that the team captured more fish in sampling efforts this year than they did in 2021 when comparing fish densities within the nets.

Monitoring efforts measure fish presence and density, insect abundance, and fish feeding habits within the newly restored area. The team also monitors nearby Jack Block Park, which represents a more natural shoreline not being restored to use as a reference and comparison for the team’s measurements. Similar monitoring efforts were conducted in 2021, before the new habitat was constructed, so the team would have a baseline to compare to.

The goal of restoring habitat is to provide higher quality food for juvenile salmon as they migrate to the ocean, enabling them to grow larger and have a better chance of survival. If the results show that salmon are using the habitat for resting and feeding, it will be a good indication that more “salmon rest stops” could help salmon in the Duwamish estuary.

Read the full blog by Long Live the Kings

Hiring for SAFS Teaching Assistant for duties in Winter Quarter 2025

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The School of Aquatic and Fishery Sciences (SAFS) is hiring a Teaching Assistant for duties in Winter Quarter 2025

 Course: FISH 464A Arctic Marine Vertebrate Ecology

Instructor: Kristin Laidre

Dates: December 16, 2024 – March 15, 2025

Compensation: Position is 50% FTE; salary is commensurate with academic standing

(ASE salary schedule: https://facstaff.grad.uw.edu/advising-resources/funding-management/administering-assistantships/ta-ra-salaries/)

Deadline to Apply: NOVEMBER 6, 2024. Priority consideration given to applications received by this date. Applications will be accepted after this date if the position remains unfilled

COURSE DESCRIPTION:

Explores the structure and function of Arctic ecosystems, life history, and adaptations of vertebrates, and how species are affected by climate warming. Emphasizes upper-level trophic interactions, evolutionary drivers, food chains, energy transport paths, and influence of sea ice. Case studies provide background on Arctic conservation and management. Prerequisite: BIOL 180.

TO APPLY:

To apply, complete application form* here and upload the following additional documents (under one cover, with course name and number and your full name in the document’s title):

  1. Cover letter – include description of your general background, why you are applying for this ASE position, strengths and any abilities directly related to the specific course(s) that you would bring to the position, etc.
  2. Current resumé
  3. Name, title, and contact information (email, phone number) for three references who are familiar with your teaching abilities and/or knowledge and experience relevant to the content of the course(s) for which you are applying.

*To access the form, log in using your @uw.edu address (https://mail.google.com/a/uw.edu).

Full position description here. Questions may be directed to safsadv@uw.edu.

Giant fish keep washing up in Oregon

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In a new video created by the Burke Museum, Fish Collections Manager Katherine Maslenikov takes us behind the scenes to answer questions about the giant bizarre Sunfish washing up on the shores of Oregon. Where are these fish coming from? What do they eat to get so large? Why are they the “pinnacle of fish evolution”?

Visit the Burke Museum YouTube channel

Harbor seals and fish parasites: How two undergrads contributed to major discoveries in cryptic diversity

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Almost 25 years ago, an undergraduate took the SAFS “Aquatic Ecological Research in Alaska (AERA)” summer field class, as part of the Alaska Salmon Program (ASP). Always interested in marine mammals, Donna Hauser, a biology student who ended up double majoring in Biology and Aquatic and Fishery Sciences, started a study of the resident harbor seals in Iliamna Lake for her independent research project. Alaska’s largest lake and 7th largest in the US, students from the University of Washington have been conducting research on Iliamna Lake since the early 1960s, and these harbor seals are well-known to people living around the lake, but formal research on the seals was very limited prior to Donna’s work.

Donna Hauser
An Iliamna Lake harbor seal. Research conducted under NOAA scientific research permit 15126-03.

Combined with data collected by a subsequent student in the class, Donna published her findings in the Aquatic Mammals scientific journal in 2008, looking into the summer diet and consumption patterns of Iliamna Lake’s resident harbor seals. Going on to complete her MS and PhD at SAFS on killer whales and belugas, respectively, Donna is now a Research Associate Professor working for the University of Alaska Fairbanks. “Interest in these seals increased and after sampling for genetic tissue by Donna and others, a new paper has now been published by Biology Letters”, shared Tom Quinn, SAFS Professor and advisor to Donna for her undergraduate project at SAFS. “The essence of the paper is that these seals, which are easily capable of swimming to and from Bristol Bay and thus integrating with seals there, are highly different from them genetically.”

Peter Westley
FRI crew surveying for seal scats. Research conducted under NOAA scientific research permit 15126-03.

In comparison with other harbor seals, it has been revealed that there is more genetic similarity between harbor seals along their whole Pacific Rim range (e.g., based on samples from California to Japan, including Bristol Bay) than there is between Bristol Bay and Iliamna Lake. “This is a very cool discovery. While geneticists have done the bulk of the work to show how genetically different these seals are from other harbor seals, it was Donna’s opening, back in 2001, that got us thinking about them,” Tom said.

Donna Hauser
Iliamna Lake harbor seals. Research conducted under NOAA scientific research permit 15126-03.

Fast forward to 2012, when another undergraduate, Brian Harmon, headed up to Iliamna Lake for the same AERA class. “Brian’s serendipitous observation of parasites in sculpins initiated a study on the genetic status of the parasites, in comparison to the similar ones commonly seen in 3-spine and 9-spine sticklebacks”, Tom shared. Sticklebacks are a family of ray-finned fishes, and are found in freshwater, brackish, and marine environments and consume zooplankton, including copepods which are the source of infection. Sculpins are a primarily benthic species and generally do not appear to consume copepods in these environments, leading researchers to wonder what the mechanism is for widespread infection by the parasites.

“The study was expanded from Iliamna Lake to Lake Aleknagik, another Alaska Salmon Program site, and included parasites from two sculpin species as well as both stickleback species, and involved collaboration with parasitologists and geneticists,” Tom said. “This study, recently published in Parasitology in May 2024, shows that the parasites in the sculpins are highly different from those in the sticklebacks, and probably should be a distinct species”. After obtaining his BS in 2012, Brian completed his MS in Natural Resource Sciences at the University of Nebraska in 2017, and now works in the sustainability space as a Principal Technical Advisor for LMI.

Brian Harmon
Brian Harmon’s observation of parasites in sculpins initiated a study on the genetic status of the parasites, in comparison to the similar ones commonly seen in 3-spine and 9-spine sticklebacks.

The so-called “cryptic diversity” of both these species – Iliamna’s harbor seals and parasites found in fish in Alaska’s lakes – means that although they are superficially similar, their genetics are very different. “I credit the terrific opportunities of the AERA class and the creativity and hard work by these two students for a couple of major discoveries,” Tom said. “I am very proud of both Donna and Brian, for their insights and eagerness to see the projects through, and the wonderful collaborators inside and outside of the University of Washington, without whom these projects would have died on the vine.”

2024 Preview of the Eastern Bering Sea Pollock Stock Assessment

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Join us for the 2024 Preview of the Eastern Bering Sea Pollock Stock Assessment, held live on Wednesday 6 November at 4pm. It will take place on the UW Campus in Room 102 on the first floor of the Fishery Sciences Building (1122 NE Boat Street). 
 
Dr. Jim Ianelli, NOAA Fisheries Alaska Fisheries Science Center (AFSC) scientist and SAFS affiliate professor, will present the EBS pollock assessment model and the most recent trends in the EBS pollock stock.
 
The event will be followed by a catered reception. We look forward to you joining us!
 
Please share with interested parties. We would also ask you to (nonbinding) RSVP to Chris Anderson (cmand@uw.edu) as per UW event policy.

Download the poster

Bitter crabs…attitude problem or parasitic infection?

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Bitter crab syndrome might sound like an attitude problem, but it’s actually a condition faced by two very valuable fisheries in Alaska: snow crabs and Tanner crabs. So-called for the bitter flavor of crab meat in infected crabs, bitter crab syndrome (BCS) is caused by a parasitic dinoflagellate of the genus Hematodinium and infects a number of crustacean species around the globe.

Aspen Coyle, a SAFS graduate student who is a member of the Roberts Lab, is conducting research which looks more closely at the impact of BCS on Alaska’s snow and Tanner crab fisheries, which have a combined worth of over $44 million. Aspen’s project is examining rates of infection using survey data from specific sub-populations of Southeast Alaska Tanner crab. “From the mid to late 2010s, data from the Bering Sea showed steadily rising rates of bitter crab syndrome. It remains an important area of study as we want to know what factors impact infection and if these are impacted by environmental conditions,” she shared.

Grace Crandall
Hemolymph from an uninfected crab. If it was infected, it would be a milky white.

“In my research, I’ve been measuring all of the physical characteristics of Tanner crabs including carapace, sex, infections, injuries, but also capturing environmental data such as bottom temperature, bottom type silt, latitude, day of the year,” Aspen said. Using generalized linear mixed models, Aspen hopes to try and tease out what factors are associated with the parasite from the genus Hematodinium, which is responsible for BCS.

During experiments designed to simulate changing ocean temperature and the impact of warmer or cooler water temperatures on infection rates, Aspen found that in heatwave episodes, some genes and pathways are differentially expressed in infected crabs. Bitter crab syndrome is a fatal condition, but the timeline between infection and mortality remains uncertain due to the slow-developing rate of infection.

Grace Crandall
Tanner crabs in the NOAA labs in Juneau, Alaska.

Aspen is using a huge amount of Alaska Department of Fish and Game (ADFG) survey data from 2005 to 2019 to input into a model, which includes more than 151,000 measurements taken from crabs. “We’ve also found that females are more prone to have visible infections than males,” she said. What exactly does infection in a crab look like? “The legs of healthy snow and Tanner crabs tend to have a pale pink color. As the disease multiplies inside infected crabs, the cells of the parasite get so prevalent that turns their hemolymph – basically their blood – milky and white. This gives the crab a pale, bleached appearance,” Aspen added. 

The sex-specific differences between males and females is an interesting insight into bitter crab syndrome. “While females were more prone to having visible infections than males overall, females that were producing more eggs had lower rates of infection,” Aspen said. “The amount of healthy, egg-producing females is critical to the health of these fisheries. And so having deeper insight into the impact of bitter crab syndrome on female populations, and how females may be more resistant or react to BCS differently, is critical information for fishery managers.”

How does the parasite move around crustacean populations? “It hasn’t been confirmed without a doubt, but a consensus is forming that it is waterborne, directly infecting one crab and then moving on to the next,” Aspen shared. “A pattern observed in my model, which matches previous studies, has been that the older the crab shell, the less likely the chance of infection.” Tanner crabs have a terminal molt, which means they stop molting for the final time around seven years old. This shell is the one they have until they die, which slowly degrades over time. “What we have found is that when the crab is in the stages before a new shell is developed – where they have a soft shell immediately post-molt, which is easily penetrated – that’s likely when the parasite infects the host,” Aspen added.

Aspen Coyle
While working for the Alaska Department of Fish and Game (unrelated to her current project), Aspen joined a Bering Sea crab survey.

In a related project with NOAA, Aspen is examining gene expression in infected and uninfected crabs held at various temperatures. Keep an eye out for a future story on this topic!

Currently in her fifth year of a master’s program at SAFS, Aspen is in the process of writing up and publishing her research. She is also contributing to a chapter of a book for the American Fishery Society on the experiences of women and femmes in fishery sciences.

Community and connection with the Alaska Salmon Program

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It’s not all work while visiting the Alaska Salmon Program camps for the summer field season. Students head up to southwest Alaska, some for over three months, and downtime is a chance to explore, connect with their peers, and experience living in a field camp.

Naomi Prahl
Lots of fish!

Some students are avid fishers and get to experience fishing in a location that vacationers usually pay a large sum to enjoy. Ryan Luvera, a SAFS and Marine Biology double major entering his third year, shared: “Outside of a typical workday I love to fish, and the fishing up here is truly world class.” 

Whether you have visited the camps in person or only seen pictures, the location continues to be one that awes. Hiking Church Mountain, a familiar sight towering over the Lake Nerka field camp, is a tradition among those who spend time with the Alaska Salmon Program. “It was very steep but so worth it, both for the views and the sense of accomplishment. We got a bonus lesson on the history of glaciation in the valleys visible from the top. It was amazing to see the concepts physically laid out in the landscape,” Emma Meyer, a junior at SAFS, said. 

Some of the more subtle experiences are among the most memorable. “One of my favorite things to do was have lunch in the tundra,” said Callie Murakami, a SAFS major now in her third year. “Some days we packed lunches and snacks to have while we were out, and we would sit in the open tundra to eat. The ground was soft, there were crowberries and cloudberries growing everywhere, and we could all chat and take a break. Even in the rain, nothing could beat a tundra lunch.” 

Emma Meyer
A view from the top of Church Mountain.

Building a sense of community is a key part of the experience, from studying and working during the day, to pitching in for mealtimes and spending evenings together. “As a class, we all enjoyed each other’s company and would often play speed solitaire, cambio, and bananagrams in the evening after dinner,” shared Emma Bell, who will soon be graduating from SAFS. “One night we made popcorn and had a movie night which was also really fun.”

For many students, visiting Alaska is a highlight of their time studying at the University of Washington. “Last year I was at Friday Harbor Labs, and I thought that was going to be the peak experience of my college experience, and then I came to Aleknagik,” said Ryan Luvera. “This is truly an experience like no other, being able to be in living quarters with so many brilliant minds, I wish I could spend every summer here!”

Ryan Luvera
Salmon are not the only wildlife in these parts!

For others, it’s an opportunity to see another side of the fishery that they have experience with. Naomi Prahl, a SAFS major going into her senior year, shared: “I work as a commercial fisherman in the Bristol Bay sockeye salmon fishery, which is the fishery that utilizes the ASP data for their management decisions. Working in the fishery gave me a first look at how incredible the Bristol Bay ecosystem is, and getting to be a student with ASP this summer felt like a full circle moment. I got to see the ‘behind the scenes’ of the fishing job that I love so much. There was something almost magical about getting to see the salmon in every life stage through the class this summer after working a fishing season beforehand.”

Putting into practice key skills learned throughout their academic journeys is a central part of the Alaska Salmon Program and sets students on course for a range of opportunities in the future, from further study in graduate programs to careers in academic institutions and fishery-related fields. “I learned a lot of valuable skills about field and professional work, such as preparation and flexibility when it comes to working in the field, and how to work and communicate better as a team,” shared Callie Murakami.

How do students find out about this opportunity to spend a summer in Alaska? “While I was attending community college my only intention after I graduated was to transfer to SAFS,” said Emma Bell. “I was constantly looking at the SAFS webpage and seeing all the cool opportunities they offered and thought that the Alaska Salmon Program seemed really incredible. When I saw the flier posted, I was so excited to fill out an application.”

Emma Meyer
A trek through the tundra.

Hundreds of students from UW have spent time with the Alaska Salmon Program over the last few decades, immersing themselves in one of the world’s most remarkable ecosystems. For future students, Naomi Prahl shared some advice: “Just get excited. It’s such an incredible and unique opportunity and I think the way to appreciate it fully would be to dive in headfirst. Don’t hide your enthusiasm and share what you’re excited to learn about. When you get there, try everything. Don’t shy away from asking questions and trying things you have no experience with. Take full advantage of the learning opportunities presented.”

The return of the sockeye: Read Part 1 of the 2024 ASP blog series