GEMM Lab 2021: A Year in the Life

Another year has come and gone, and the GEMM Lab has expanded in many facets! Every year it gets just a little bit harder to succinctly summarize all of the research, outreach, and successes that the GEMMs accomplish but it is an absolute honor and thrill to be a member of this lab. So, please enjoy the 6th edition of a GEMM Lab Year in the Life!

Our lab has almost doubled in size since I wrote the 2020 edition of this blog! This year we welcomed the arrival of two postdocs (Drs. Alejandro [Ale] Fernández Ajó and KC Bierlich) and two Master’s students (Allison Dawn and Miranda Mayhall). Ale and KC joined us as freshly minted Drs., as Ale defended his doctoral thesis from Northern Arizona University in April, while KC graduated in May from Duke University. Both of them immediately jumped into GRANITE fieldwork, scooping gray whale poop and flying drones (more below). Allison also dove headfirst into gray whale fieldwork as she co-led the TOPAZ and JASPER projects with me (Lisa) after defending her undergraduate thesis and graduating from the University of North Carolina with highest honors in the spring. Miranda, a U.S. Army Intelligence veteran, also joins us from the East Coast as she moved from Virginia to Oregon with her 10-year-old daughter, Mia, and two dogs, Angus and Mr. Gibbs. Unlike our other new arrivals, Miranda’s research does not relate to gray whales as she is part of the GEMM Lab’s newest research project…

There are exciting developments in the research project realm of the GEMM Lab every year. This year’s new project, HALO (Holistic Assessment of Living marine resources off Oregon), is particularly exciting as it is a joint project with the Cornell Lab, with GEMM Lab PI Leigh collaborating with Dr. Holger Klinck to better understand cetacean distributions off Oregon. HALO will involve monthly survey cruises aboard MMI’s R/V Pacific Storm along the Newport Hydrographic line (65 nm to 5 nm off Newport), where three Rockhopper hydrophones have been deployed and are passively monitoring cetacean acoustics. The HALO team, which includes GEMM students Miranda and PhD candidates Dawn Barlow and Rachel Kaplan, has already had two successful cruises this year! Check out the HALO website to stay tuned for updates throughout 2022. In addition to starting new research projects in our Oregon backyard, the GEMM Lab has also ventured further north, to the more frigid waters of Kodiak, Alaska. Postdocs KC and Ale went on a scouting mission to Kodiak Island to see whether the multidisciplinary methods we use in the GRANITE project to study PCFG gray whales in Oregon, can also be applied to other gray whales in other study areas. The reconnaissance trip was a huge success with KC and Ale making vital connections with potential collaborators and managing to collect some pilot data (drone flights, prey samples, and one fecal sample!). Both of these new ventures are funded by sales and renewals of the special Oregon gray whale license plate, which benefits MMI. We gratefully thank all the gray whale license plate holders, who made this research possible, and encourage any Oregonians that don’t have a whale on their tale yet, to do so in 2022!

These new research ventures certainly do not mean that we neglected our already established field research projects – in fact, most of them have flourished and thrived this year! Rachel and Dawn returned as marine mammal observers to the R/V Shimada for the May stint of the Northern California Current research cruise. They observed Dall’s porpoise, Northern right whale & Pacific white-sided dolphins, as well as killer, humpback, & fin whales. These sightings will add to the growing OPAL (Overlap Predictions About Large whales) dataset that both Rachel and postdoc Solène Derville are analyzing to better understand whale distribution patterns in Oregon waters. Speaking of OPAL, MMI Faculty Research Assistant Craig Hayslip and Leigh continued to take to the skies in U.S. Coast Guard helicopters to obtain monthly cetacean distribution data, which is also being used in the OPAL project to identify the co-occurrence between whales and fishing effort in Oregon to reduce entanglement risk. Both of our gray whale projects, GRANITE (Gray whale Response to Ambient Noise Informed by Technology & Ecology) and TOPAZ (Theodolite Overlooking Predators & Zooplankton)/JASPER (Journey for Aspiring Scientists Pursuing Ecological Research) had another year of successful field seasons. The GRANITE team, which includes Leigh, Todd Chandler, Ale, KC, PhD student Clara Bird, and myself, headed out in search of gray whales earlier than usual this year to document the potential effects of a National Science Foundation (NSF) funded seismic survey, which was conducted off the Oregon coast, on gray whales in the area. By the end of October, we had conducted 80 drone flights, collected 48 and 66 fecal and prey samples (respectively), and seen 36 individual whales during 201 sightings. Down south in Port Orford, the TOPAZ/JASPER project experienced a passing of the torch as I stepped down from the team lead position (which I held since 2018) and handed the project reins over to Allison. We co-led another fantastic field season this year. While whale sightings were much lower than in previous years (read some musings here), the project continued to be successful at making real impacts on young people’s lives as we once again engaged a local Pacific High School student (Damian Amerman-Smith) and two OSU undergraduates (Nadia Leal & Jasen White) in the field work. While our annual reach may be small in terms of numbers, the impact we have is huge, with many of the high school interns (including this year’s) deciding to go to college and/or to study biology directly as a result of our project.

TOPAZ/JASPER certainly is not the only project in our lab that engages students in ecological research. This year, we collectively oversaw and mentored 13 students. The OBSIDIAN (Observing Blue whale Spatial ecology to Investigate Distribution In Aotearoa New Zealand) project was assisted by three interns (Grace Hancock, Mateo Estrada Jorge, and Mattea Holt Colberg) overseen by Dawn and Leigh. Grace worked on maintaining the New Zealand blue whale photo-ID catalogue and won best student poster at our department’s annual student conference (RAFWE) for this work. Mattea, a 2020 TOPAZ/JASPER team member, switched study species and assisted Dawn in validating blue whale calls and songs. Mateo was a NSF Research Experience Undergraduate (REU) who conducted an analysis on blue whales and earthquakes. Clara also supervised a REU student with Leigh: Marc Donnelly, who created a habitat map for the GRANITE project. Rachel mentored Amanda Kent, an Undergraduate Research, Scholarship, & the Arts (URSA) Engage student, who helped her conduct a literature review about two Oregon krill species that are primary prey of whales. Over the summer, we had two student workers (Noah Goodwin-Rice & Julia Parker) join us in our efforts to better understand gray whale prey. Noah assisted us by sorting and identifying gray whale prey samples collected this summer and Julia wrapped up the microplastics analysis of gray whale prey and fecal samples. In the fall, both Clara and Allison supervised students (Kathryne Macallan & Jasen White, respectively) taking the Coastal & Estuarine Research Management class in our department who produced independent research projects during the term. Kathryne investigated the relationship between body length and blow intervals of gray whales during different behavioral states, while Jasen dove into the relationship between zooplankton abundance and environmental covariates. 

The sharing of our research and expertise was not limited to mentoring students. Despite most conferences and seminars still occurring virtually this year due to the pandemic, the GEMM Lab presented numerous talks including at the State of the Coast (Rachel, Dawn, Leigh, & myself), International Biologging Symposium (Solène), HMSC Research Seminar (Ale & Solène, KC), and the Northwest Student Society of Marine Mammalogy chapter conference (Clara, Dawn, & myself), to name a few. Furthermore, Clara and I were guest lecturers once again for Dr. Renee Albertson’s marine mammal classes in our department, and Solène gained her first teaching experience by creating and leading a data visualization workshop (called “Pimp my figure!”) for RAFWE in May, which she reiterated at the University of New Caledonia in October.

Another huge accomplishment comes from the southern hemisphere as the hard work and time that Leigh and Dawn dedicated to OBSIDIAN and the results generated contributed to the denial of a seabed mining permit to extract iron sands in the South Taranaki Bight. This milestone has been years in the making, starting in 2013 when Leigh published her hypothesis that an unrecognized blue whale foraging ground existed in New Zealand. Since then, Leigh and Dawn have been building a tower of knowledge about these resident New Zealand blue whales block-by-block. They first confirmed Leigh’s hypothesis by presenting a bounty of evidence in support of this resident population, then assessed the skin condition of these whales, modeled the functional relationships between oceanography, krill and the distribution of blue whales, discovered temporal and spatial lags between wind, coastal upwelling, and blue whale occurrence, and most recently, developed dynamic models to forecast blue whale distribution three weeks into the future. We are extremely proud of the direct applications that the OBSIDIAN research outputs have had on the management and conservation of these New Zealand blue whales – hurrah to Leigh & Dawn!!

Other hurrahs this year include that Rachel passed her College of Earth, Ocean, & Atmospheric Sciences qualifying exam, now making her a PhD Candidate. Clara also reached a graduate milestone this year as she not only formed her PhD committee but also successfully defended her research review in the spring. Additionally, Clara became a certified drone pilot right before the start of the GRANITE field season and joined Todd and KC as pilots this summer. The lab and its members also received numerous grants and awards. There are too many to name for this blog, but we are very grateful for all of them! I do want to highlight two here: Dawn was awarded the Bob Moch memorial endowment award that recognizes service to the Hatfield Marine Science Center (HMSC) and broader Oregon coast community. I cannot think of anyone more deserving of this award than Dawn who truly does so much to serve and better the HMSC and Oregon coast communities! Clara was awarded a prestigious ARCS (Achievement Rewards for College Scientists) scholarship which provides awards to academically outstanding students to further their scientific knowledge. 

We have once again been prolific writers, contributing 24 total peer-reviewed publications to 17 different scientific journals. If you are in the mood for some holiday reading, you will find the full list of publications at the end of this post.

And YOU, our awesome, supportive readers, have once again been supportive viewers, with a whopping 27,135 views of our blog this year!!! Thank you for joining us on our 2021 journey! We hope you have enjoyed the tales that we have told and the knowledge we have (hopefully) conveyed. We wish you all restful, happy, and most importantly, healthy holidays and hope you will join us again in 2022!

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Andréfouët, S., Derville, S., Buttin, J., Dirberg, G., Wabnitz, C.C.C., Garrigue, C., & Payri, C. E. 2021. Nation-wide hierarchical and spatially-explicit framework to characterize seagrass meadows in New Caledonia, and its potential application to the Indo-Pacific. Marine Pollution Bulletin 173:113036.

Barlow, D.R., & Torres, L.G. 2021. Planning ahead: Dynamic models forecast blue whale distribution with applications for spatial management. Journal of Applied Ecology. (Link)

Barlow, D.R., Klinck, H., Ponirakis, D., Garvey, C., & Torres, L.G. (2021). Temporal and spatial lags between wind, coastal upwelling, and blue whale occurrence. Scientific Reports 11(1):1-10. (Link)

Beal, M., … Torres, L.G., et al. 2021. Global political responsibility for the conservation of albatrosses and large petrels. Science Advances 7(10):eabd7225.

Bierlich, K.C., Schick, R.S., Hewitt, J., Dale, J., Goldbogen, J.A., Friedlaender, A.S., & Johnston D.J. 2021. A Bayesian approach for predicting photogrammetric uncertainty in morphometric measurements derived from UAS. Marine Ecology Progress Series. DOI:

Bierlich, K.C., Hewitt, J., Bird, C.N., Schick R.S., Friedlaender, A.S., Torres, L.G., Dale, J., Goldbogen, J.A., Read, A., Calambokidis J., & Johnston, D.W. 2021. Comparing uncertainty associated with 1-, 2-, and 3D aerial photogrammetry-based body condition measurements of baleen whales. Frontiers in Marine Science 8:749943. doi: 10.3389/fmars.2021.749943  

Bonneville, C.D., Derville, S., Luksenburg, J.A., Oremus, M., Garrigue, C. 2021. Social structure, habitat use and injuries of Indo-Pacific Bottlenose Dolphins (Tursiops aduncus) reveal isolated, coastal, and threatened communities in the South Pacific. Frontiers in Marine Science 8:1–14.

Clatterbuck, C.A., Lewison, R.L., Orben, R.A., Ackerman, J.T., Torres, L.G., Suryan, R.M., Warzybok, P., Jahncke, J., & Shaffer, S.A. 2021. Foraging in marine habitats increases mercury concentrations in a generalist seabird. Chemosphere 279:130470.

D’Agostino, V.C., Fernandez, A.A.A., Degrati M., Krock, B., Hunt, K.E., Uhart, M.M., & Buck, C.L. 2021. Potential endocrine correlation with exposure to domoic acid in Southern Right Whale (Eubalaena australis) at the Península Valdés breeding ground. Oecologia 1-14.

Dillon, D., Fernandez, A.A.A., Hunt, K.E., & Buck, C.L. 2021. Investigation of keratinase digestion to improve steroid hormone extraction from diverse keratinous tissues. General and Comparative Endocrinology 309:113795.

Fernandez, A.A.A., Hunt, K.H., Sironi, M., Uhart, M., Rowntree, V., Giese, A.C., Maron, C.F., DiMartino, M., Dillon, D., & Buck, C.L. 2021. Retrospective analysis of the lifetime endocrine response of southern right whales calves to gull wounding and harassment: a baleen hormone approach. Integrative and Comparative Biology 61.

Fernandez, A.A.A., Hunt, K.E., Dillon, D., Uhart, M., Sironi, M., Rowntree, V., & Buck, C.L. 2021. Optimizing hormone extraction protocols for whale baleen: tackling questions of solvent: sample ratio and variation. General and Comparative Endocrinology 113828.

Garrigue, C., & Derville, S. 2021. Behavioral responses of humpback whales to biopsy sampling on a breeding ground : the influence of age-class , reproductive status , social context , and repeated sampling. Marine Mammal Science 1–16.

Gough, W.T., Smith, H.J., Savoca, M.S., Czapanskiy M.F., Fish, F.E., Potvin, J., Bierlich, K.C., Cade, D.E., Di Clemente, J., Kennedy, J., Segre, P., Stanworth, A., Weir, C., & Goldbogen, J.A. 2021. Scaling of oscillatory kinematics and Froude efficiency in baleen whales. Journal of Experimental Biology224(13):jeb237586. DOI:

Hildebrand, L., Bernard, K.S., & Torres, L.G. 2021. Go gray whales count calories? Comparing energetic values of gray whale prey across two different feeding grounds in the eastern North Pacific. Frontiers in Marine Science,

Jones, D.C., Ceia, F.R., Murphy, E., Delord, K., Furness, R.W., Verdy, A., Mazloff, M., Phillips, R.A., Sagar, P.M., Sallée, J-B., Schreiber, B., Thompson, D.R., Torres, L.G., Underwood, P.J., Weimerskirch, H., & Xavier J.C. 2021. Untangling local and remote influences in two major petrel habitats in the oligotrophic Southern Ocean. Global Change Biology 27(22):5773-5785.

Kone, D.V., Tinker, M.T., & Torres, L.G. 2021. Informing sea otter reintroduction through habitat and human interaction assessment. Endangered Species Research 55:159-176. 

Lemos, L.S., Olsen, A., Smith, A., Burnett, J.D., Chandler, T.E., Larson, S., Hunt, K.E., & Torres, L.G. 2021. Stressed and slim or relaxed and chubby? A simultaneous assessment of gray whale body condition and hormone variability. Marine Mammal Science.

Lemos, L.S., Haxel, J.H., Olsen, A., Burnett, J.D., Smith, A., Chandler, T.E., Nieukirk, S.L., Larson, S.E., Hunt, K.E., & Torres, L.G. 2021. Sounds of stress: assessment of relationships between ambient noise, vessel traffic, and gray whale stress hormone. Scientific Reports. DOI:10.21203/

Maron, C.F., Lábaque, M.C., Beltramino L., DiMartino, M., Alzugaray, L., Ricciardi, M., Fernandez, A.A.A., Adler, F.R., Seger, J., Sironi, M., Rowntree, V.J., & Uhart, M.M. 2021. Patterns of blubber fat deposition and evaluation of body condition in growing southern right whale calves (Eubalaena australis). Marine Mammal Science. DOI: 10/1111/mms.12818.

Orben, R.A., Adams, J., Hester, M., Shaffer, S.A., Suryan, R.M., Deguchi, T., Ozaki, K., Sato, F., Young, L.C., Clatterbuck, C., Conners, M.G., Kroodsma, D.A., & Torres, L.G. 2021. Across borders: External factors and prior behavior influence North Pacific albatross associations with vessel traffic. Journal of Applied Ecology.

Savoca, M.S. Czapanskiy, M.F., Kahane-Rapport, S.R., Gough, W.T., Falhbusch, J.A., Bierlich, K.C., Segre, P.S., Di Clemente, J., Penry G.S., Wiley, D.N., Calambokids, J., 
Nowacek, D.P., Johnston, D.W., Pyenson, N.D., Friedlaender, A.S., Hazen, E.L., & Goldbogen, J.A. 2021. Baleen whale prey consumption based on high-resolution foraging measurements. Nature 599:85–90.

Stephenson, F., Hewitt, J.E., Torres, L.G., Mouton, T.L., Brough, T., Goetz, K.T., Lundquist, C.J., MacDiarmid, A.B., Ellis, J., & Constantine, R. 2021. Cetacean conservation planning in a global diversity hotspot: dealing with uncertainty and data deficiencies. Ecosphere 12(7):e03633.

Thompson, D.R., Goetz, K.T., Sagar, P.M., Torres, L.G., Kroeger, C.E., Sztukowski, LA., Orben, R.A., Hoskins, A.J., & Phillips, R.A. 2021. The year-round distribution and habitat preferences of Campbell albatross (Thalassarche impavida). Aquatic Conservation: Marine and Freshwater Ecosystems 31(10):2967-2978.

Looking for micro in the macro: microplastics in cetaceans

By Lisa Hildebrand, PhD student, OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

Since we find ourselves well into the cozy winter season, I thought it was an appropriate time to update you all on our project COZI (Coastal Oregon Zooplankton Investigation). COZI is a cross-college collaborative effort, led by GEMM PI Leigh Torres, that aims to better understand the quality of Oregon coast zooplankton prey and its impacts on gray whale foraging ecology and health. Leigh is joined by three other early-career female scientists, Dr. Sarah Henkel, Dr. Kim Bernard, and Dr. Susanne Brander, that each contribute a different area of expertise to the project. The quartet recently graced the cover of the Oregon Stater in an article all about COZI written by Nancy Steinberg (which I highly recommend reading!). To date, the COZI team (which includes myself as well as many other students) has found that the caloric content of the six predominant zooplankton species in Oregon coastal waters differs significantly, with Dungeness crab megalopae coming out on top as a caloric goldmine (Hildebrand et al. 2021). We found that these Oregon prey are calorically competitive with the predominant benthic amphipod that gray whales feed on in the Arctic, which has interesting implications for foraging ground selection and use of gray whales in the eastern North Pacific (read about it in detail in my blog about the publication). Now that we know that Oregon zooplankton quality differs in terms of calories, we are curious to determine whether these species are impacted by microplastics in the environment, to what extent, and how gray whales may be affected.

What is in those zooplankton? A microscopic view of several mysid shrimp collected in Oregon coastal waters. Source: L. Hildebrand.

To answer these questions, we are analyzing both zooplankton and gray whale fecal samples for microplastics to see what kind, and how many, microplastics we find, and whether microplastics biomagnify up the food chain. The lab analysis has just been completed and we are working on interpreting the results. We can’t let the cat out of the bag yet, but a little sneak-peek of what we have found is that there are different levels of microplastic loads by zooplankton species, which also end up in the whale poop. So, until we finalize those results for sharing, I am going to review the field of microplastics research, with a particular focus on cetaceans. Avid readers of our blog may recall that I wrote a blog about marine plastics at the start of 2019. In that blog, I mentioned that a GoogleScholar search of “microplastics marine” generated 7,650 results. To get an idea of how microplastics research in the marine environment has progressed since I wrote my 2019 blog, I conducted the same GoogleScholar search for this blog but I limited the results to studies published between 2019-2021. GoogleScholar presented me with a whopping 18,000+ results, which shows the rapidity at which the field of marine microplastics research has grown in the last couple of years. The studies span all kinds of topics from distribution & occurrence, to chemical behaviors & interactions with other toxins, to sources & sinks (to name a few!). The results encompass both laboratory and field studies investigating samples from all five oceans of the world. Unfortunately, the title of my blog from two years ago still rings very true: plastics truly are ubiquitous in the marine environment. 

In my last blog, I listed three cetacean species that had been found to contain microplastics: a True’s beaked whale (Lusher et al2015), a humpback whale (Besseling et al.2015) and an Indo-Pacific humpback dolphin (Zhu et al.2018). Reflective of the marine microplastics field in general, this list has also grown considerably in the last two years. Since 2019, microplastics have been detected in harbor porpoises (Philipp et al. 2021), common dolphins (Nelms et al. 2019), striped dolphins (Novillo et al. 2020), bottlenose dolphins (Battaglia et al. 2020), Atlantic white-sided dolphins (Nelms et al. 2019), beluga whales (Moore et al. 2020), and Bryde’s & sei whales (Zantis et al. 2021). At this point, I would posit that the main reason this list is not longer is due to the time it takes to collect and analyze samples for microplastics, rather than microplastics being absent in other cetacean species. During my research for this blog, I noticed that the studies on microplastics in cetaceans are starting to shift from focusing on simply determining microplastic occurrence to attempting to estimate levels of exposure and/or ingestion, determine the main source (from water vs. from prey), and long-term consequences. 

Graphical abstract taken from Zantis et al. (2021) representing the pathway of microplastics exposure of large marine filter-feeders. Source: Zantis et al. (2021).

A study published this year examined fecal samples of Bryde’s and sei whales in coastal waters in New Zealand and detected 32 ± 24 microplastics per 6 g of feces (Zantis et al. 2021). By extrapolating these values to the proportions of prey species in the whales’ diet, the authors estimate that these whales consume over 24,000 pieces of microplastics per mouthful of prey, or more than 3 million microplastics per day. Another study (Shetty 2021) in the same geographic region investigated the levels of microplastics in coastal surface waters, which allowed the authors to estimate whether the source of the microplastics that the Bryde’s and sei whales ingest come from the water or the prey. They found that the estimated level of microplastics that the whales consume daily from their prey is four orders of magnitude higher than the microplastic levels in the coastal waters. This finding strongly suggests that the predominant mode of exposure of large filter feeders, such as baleen whales, for microplastic pollution comes from their prey through biomagnification (not just from the ambient sea water).

The GEMM Lab collecting a gray whale fecal sample along the Oregon coast captured from a drone. Source: GEMM Lab.

COZI aims to conduct similar analyses as these studies described above to understand the exposure of coastal Oregon zooplankton to microplastics and how this may be affecting gray whales. Stay tuned for those results!

I am aware that I have painted a very bleak (but true) picture of microplastic pollution in our oceans in this blog but there are things you can do to help reduce microdebris in the environment!

  1. A major source of pollution in the ocean comes from microfibers through our laundry. You can help stop this pathway by simply using a Cora Ball or installing a filter (such as this one) in your washing machine that captures microfleece & polyester fibers.
  2. Minimize your use of single-use plastics. There are so many ways to do so including reuseable water bottles, travel mugs for coffee or tea, fabric totes as shopping bags, carry a set of utensils for takeout food, beeswax wraps instead of plastic wrap or sandwich bags.
  3. Use public transport when possible as another huge source of microplastics comes from tire treads! This solution also helps reduce your carbon footprint.

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Battaglia, F.M., Beckingham, B.A., & McFee, W.E. 2020. First report from North America of microplastics in the gastrointestinal tract of stranded bottlenose dolphins (Tursiops truncatus). Marine Pollution Bulletin 160:111677.

Besseling, E., et al. 2015. Microplastic in a macro filter feeder: humpback whale Megaptera novaeangliae. Marine Pollution Bulletin 95: 248-252.

Hildebrand, L., Bernard, K.S., & Torres, L.G. 2021. Do gray whales count calories? Comparing energetic values of gray whale prey across two different feeding grounds in the eastern North Pacific. Frontiers in Marine Science.

Lusher, A.L., et al. 2015. Microplastic and macroplastic ingestion by a deep diving, oceanic cetacean: the True’s beaked whales Mesoplodon mirus. Environmental Pollution 199: 185-191.

Moore, R.C., et al. 2020. Microplastics in beluga whales (Delphinapterus leucas) from the eastern Beaufort Sea. Marine Pollution Bulletin 150:110723.

Nelms, S.E., et al. 2019. Microplastics in marine mammals stranded around the British coast: ubiquitous bus transitory? Scientific Reports 9:1075.

Novillo, O., Raga, J. A., & Tomás, J. 2020. Evaluating the presence of microplastics in striped dolphins (Stenella coeruleoalba) stranded in the western Mediterranean Sea. Marine Pollution Bulletin 160:111557.

Philipp, C., et al. 2021. First evidence of retrospective findings of microplastics in harbor porpoises (Phocoena phocoena) from German waters. Frontiers in Marine Science.

Shetty, D. 2021. Incidence of microplastics in coastal inshore fish species and surface waters in the Hauraki Gulf, New Zealand. Master’s thesis, University of Auckland, New Zealand.

Zantis, L.J., et al. 2021. Assessing microplastic exposure of large marine filter-feeders. Science of The Total Environment 151815.

Zhu, J., et al. 2018. Cetaceans and microplastics: First report of microplastic ingestion by a coastal delphinid, Sousa chinensis. Science of the Total Environment 659: 649-654.

Of snakes and whales: How food availability and body condition affect reproduction

Clara Bird, PhD Student, OSU Department of Fisheries, Wildlife, and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

Over six field seasons the GEMM lab team has conducted nearly 500 drone flights over gray whales, equaling over 100 hours of footage. These hours of footage are the central dataset for my PhD dissertation, so it’s up to me to process them all. This process can be challenging, tedious, and daunting, but it is also quite fun and a privilege to be the one person who gets to watch all the footage. It’s fascinating to get to know the whales and their behaviors and pick up on patterns. It motivates me to get through this video processing step and start doing the data analysis. Recently, it’s been especially fun to notice patterns that I’ve seen mentioned in the literature. One example is adult social behavior. 

There are two categories of social behavior that I’m interested in studying: maternal behavior, defined as interactions between a mom and its calf, and general social behaviors, defined as social interactions between non-mom/calf pairs. In this blog I’ll focus on general social behaviors, but if you’re interested in maternal behavior check out this blog. General social behavior, which I’ll refer to as social behavior moving forward, includes tactile interactions and promiscuous behaviors (Torres et al. 2018; Clip 1). While gray whales in the PCFG range are primarily foraging, researchers have observed increases in social behavior towards the end of the foraging season (Stelle et al., 2008; Torres et al., 2018). We think that this indicates that the whales are starting to focus less on feeding and more on breeding. This tradeoff of foraging vs. socializing time is interesting because it comes at an energetic cost.

Clip 1. Example of social interaction between a male and female gray whale off the coast of Oregon, USA. Collected under NOAA/NMFS permit #21678

Broadly, animals need to balance the energetic demands of survival with those of reproduction. They need to reproduce to pass on their genes, but reproduction is energetically demanding, and animals also need to survive and grow to be able to reproduce. The decision to reproduce is costly because reproduction requires energetic investment and time investment since animals do not forage (gaining energy) when they are socializing. Consequently, only animals with sufficient energy reserves (i.e., body condition) to invest in reproduction actually engage in reproduction. Given these costs associated with reproduction, we expect to see a relationship between social behavior and body condition (Green, 2001) with mainly animals in good body condition engaging in social behavior because these animals have sufficient reserves to sustain the cost. Furthermore, since body condition is an indicator of foraging success and prey availability, environmental conditions can also affect social behavior and reproduction through this pathway. 

Rahman et al. (2014) used a lab experiment to study the relationship between nutritional stress and male guppy courtship behavior (Figure 1). In their experiment they tested for the effects of both decreased diet quantity and quality on the frequency of male courtship behaviors. Rahman et al (2014) found that individuals in the low-quantity group were significantly smaller than those in the high-quality group and that diet quantity had a significant effect on the frequency of courtship behaviors. Males fed a low-quantity diet performed fewer courtship behaviors. Interestingly, there was no significant effect of diet quality on courtships behavior, although there was some evidence of an interaction effect, which suggests that within the low-quantity group, males fed with high-quality food performed more courtship behaviors that those fed with low-quality food. This study is interesting because it shows how foraging success (diet quantity and quality) can affect courting behavior. 

Figure 1. A guppy (Rahman et al., 2013)

However, guppies are not the ideal species for comparison to gray whales because gray whales and guppies have quite different life history traits. A more fitting comparison would be with an example species with more in common with gray whales, such as viviparous capital breeders. Viviparous animals develop the embryo inside the body and give live birth. Capital breeders forage to build energy reserves and then rely on those energy reserves during reproduction. Surprisingly, I found asp vipers to be a good example species for comparison to gray whales.

Asp vipers (Figure 2) are viviparous snakes who are considered capital breeders because they forage prior to hibernation, and then begin reproduction immediately following hibernation without additional foraging. Naulleau & Bonnet (1996) conducted a field study on female asp vipers to determine if there was a difference in body condition at the start of the breeding season between females who reproduced or not during that season. To do this they marked individuals and measured their body condition at the start of the breeding season and then recaptured those individuals at the end of the breeding season and recorded whether the individual had reproduced. Interestingly, they found that there was a strongly significant difference in body condition between females that did and did not reproduce. In fact, they discovered that no female below a certain body condition value reproduced, meaning that they found a body condition threshold for reproduction. 

Figure 2. An asp viper

Additionally, a study on water pythons found that their body condition threshold for reproduction shifted over time in response to prey availability (Madsen & Shine, 1999). These authors found that females lowered their threshold after several consecutive years of poor prey availability. These studies are really exciting to me because they address questions that the GRANITE project team is interested in tackling.

Understanding the relationship between body condition and reproduction in gray whales is an important puzzle piece for our work. The aim of the GRANITE project is to understand how the effects of stressors on individual whales scales up to population level impacts (read Lisa’s blog to learn more). Reproduction rates play a big role in population dynamics, so it is important to understand what factors affect reproduction. Since we’re studying these whales on their foraging grounds, assessing body condition provides an important link between foraging behavior and reproduction. 

For example, if an individual’s response to a stressor is to forage less, that may lead to poorer body condition, meaning that they may be less likely to reproduce. While reduced reproduction in one individual may not have a big effect on the population, the same response from multiple individuals could impact the population’s dynamics (i.e., increasing or decreasing abundance). Understanding these different relationships between behavior, body condition, and reproduction rates is a big undertaking, but it’s exciting to be a member of the GRANITE team as this strong group of scientists works to bring together different data streams to work on this big picture question. We’re all deep into data processing right now so stay tuned over the next few years to learn more about gray whale social behavior and to find out if fat whales are more social than skinny whales. 

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Green, A. J. (2001). Mass/Length Residuals: Measures of Body Condition or Generators of Spurious Results? Ecology82(5), 1473–1483.[1473:MLRMOB]2.0.CO;2

Madsen, T., & Shine, R. (1999). The adjustment of reproductive threshold to prey abundance in a capital breeder. Journal of Animal Ecology68(3), 571–580.

Naulleau, G., & Bonnet, X. (1996). Body Condition Threshold for Breeding in a Viviparous Snake. Oecologia107(3), 301–306.

Rahman, M. M., Kelley, J. L., & Evans, J. P. (2013). Condition-dependent expression of pre- and postcopulatory sexual traits in guppies. Ecology and Evolution3(7), 2197–2213.

Rahman, M. M., Turchini, G. M., Gasparini, C., Norambuena, F., & Evans, J. P. (2014). The Expression of Pre- and Postcopulatory Sexually Selected Traits Reflects Levels of Dietary Stress in Guppies. PLOS ONE9(8), e105856.

Stelle, L. L., Megill, W. M., & Kinzel, M. R. (2008). Activity budget and diving behavior of gray whales (Eschrichtius robustus) in feeding grounds off coastal British Columbia. Marine Mammal Science24(3), 462–478.

Torres, L. G., Nieukirk, S. L., Lemos, L., & Chandler, T. E. (2018). Drone up! Quantifying whale behavior from a new perspective improves observational capacity. Frontiers in Marine Science5(SEP).