Tag: Science

Marine Mammal Strandings: Responses, Causes, and Significance

By Nicole Principe, second-year PhD student, OSU Dept of Fisheries, Wildlife and Conservation Sciences, GEMM Lab

On November 15, 2025, a juvenile humpback whale stranded alive on the Oregon Coast, showing clear evidence of entanglement in gear linked to the 2023-2024 Oregon commercial Dungeness crab fishery1(Fig. 1). A large, multi-organization response followed, including groups from the West Coast Marine Mammal Stranding Network, OSU’s Marine Mammal Institute, Pacific Marine Mammal Center, Cascadia Research Collective, Oregon Coast Aquarium, SeaLife Response, Rehabilitation, Research, and more. After an unsuccessful attempt to help the whale return to sea, trained responders and veterinarians made the difficult decision to humanely euthanize it to prevent further suffering. A full necropsy (animal autopsy) was conducted afterwards to better understand the health of the whale and why it stranded

Figure 1. A stranded humpback whale off the coast of Yachats, OR. (West Coast Marine Mammal Stranding Network)

This event drew significant public attention, with community members gathering on the beach to witness this rare and emotional scene. Seeing a large, sentient animal like a humpback whale stranded on land is deeply upsetting and it naturally raised questions: Why did this happen? Was the whale sick or injured? Why couldn’t it be rescued? These are important and understandable questions and answering them openly is a core part of marine mammal science and education.

I worked as a marine mammal stranding technician in the Southeast US for almost two years, leading responses on numerous deceased and live stranded dolphins and whales. These experiences gave me insights about the realities of marine mammal response, how stranding networks operate, why marine mammals strand, how the public can safely assist when strandings occur, and efforts being done to mitigate human-related threats.

What is a Marine Mammal Stranding?

Before getting into the details of how responses work, it’s important to define what a marine mammal stranding is. The word “stranding” is used to describe sick, injured, entangled, distressed, or dead seals, sea lions, dolphins, porpoises, and whales. Cases vary with animals either washing ashore dead or live stranding on a beach or in shallow water and being unable to return to the water without assistance (Fig. 2). A mass-stranding involves two or more individual cetaceans of the same species stranding together. Each situation is different and requires various resources, equipment, and personnel2.

Figure 2. A) A single stranded dolphin (WDC), B) A mass stranding of pilot whales (Deb Pierce), C) A stranded gray whale in Washington (Cascadia Research Collective)

Stranding Networks

The National Oceanic and Atmospheric Administration (NOAA) Marine Mammal Health and Stranding Response Program (MMHSRP) was established under the Marine Mammal Protection Act and is the governing authority that oversees national responses to stranded pinnipeds and cetaceans. The MMHSRP works in collaboration with federal and state facilities as well as via networks of regional stranding responders, involving aquariums, academic institutions, and non-governmental organizations (NGOs). Network members have a Stranding Agreement from NOAA Fisheries, ensuring that all activities performed are safe for both responders and animals3.

Many stranding networks are made up of only a small number of paid employees and rely on support and assistance from community volunteer members. These networks also rely heavily on federal funding to maintain operations, including funding staff, ordering laboratory and necropsy supplies, facility maintenance, vessel and truck costs, sample shipment, pathology testing, and more. The John H. Prescott Marine Mammal Rescue Assistance Grant Program is a critical source of funding for many stranding groups. From 2001 through 2023, the Prescott Program awarded more than $75.4 million in grants to networks across the U.S4. Proposed budget cuts by the current administration put stranding networks at risk of losing this critical funding, which could impact the level of responses, limit necropsies, or reduce long-term monitoring efforts that are essential for detecting emerging threats to ocean and human health.

Key Steps to A Stranding Response

Figure 3. The steps to a marine mammal stranding response. (Geraci & Lousnbury, 2025).

Step 1 – Stranding Network Receives a Call

Most marine mammal stranding networks operate a 24/7 hotline for the public to report stranded animals. These calls are critical for gathering information such as species, size, condition (alive or dead), location, and any visible injuries or entanglement. Photos and continued communication with the caller can greatly help responders coordinate an appropriate response.

Step 2 – Coordinating a Response

Every stranding is logistically complex, and response strategies differ greatly depending on whether the animal is alive or deceased.

Deceased animals

If an animal is found dead, it may be examined in the field or transported to a lab for further analysis. Accessing the carcass can be challenging due to tides, weather, terrain, and remoteness, often requiring coordination with volunteers and local agencies such as park officials, fire departments, or the Coast Guard.

Live Strandings

Live strandings are time-sensitive and require rapid decision-making. Once intervention is deemed necessary, responders may attempt to return the animal to sea, transport it to a rehabilitation facility, or, in some cases, humanely euthanize it. These decisions are based on the animal’s condition, likelihood of survival, resources available, and safety of both the animal and responders2.

Returning an animal to sea is a viable option only when the animal is deemed healthy and they can safely be returned to their natural habitat. Smaller animals like dolphins and porpoises may be more easily returned to the water or transported to a more appropriate location for release. Whales are typically given one to two tidal cycles to refloat on their own, but their own body weight causes immense pressure once stranded, which can lead to respiratory and circulatory collapse. Pulling a large whale back into the ocean can dislocate the tail, cause paralysis, or even break the spinal cord1. Rare, but successful refloats of whales have happened only when the animal wasn’t exhausted, the sea conditions and the slope of the beach were suitable, and heavy machinery and boats were accessible and usable5.

Rehabilitation and release can be successful for some species, particularly pinnipeds and certain small cetaceans, but outcomes vary widely6,7. Large whales, especially baleen whales, rarely survive rehabilitation due to their size and biological needs8.

Euthanasia is an option when it is necessary to end suffering of an animal in irreversibly poor condition, and the procedure can be carried out humanely, no rehab or care facility is available, rescue is not feasible, or the animal continually re-strands2. This option should only be done after all other options have been considered, proper authorities with NOAA have given approval, and a trained veterinarian is available to safely do the procedure. Oftentimes, veterinarians will administer a sedative to keep the animal calm before euthanasia. While the outcome can be sad, euthanasia is never a choice of convenience. It reflects a commitment to animal welfare, ensuring that when recovery is not possible, the animal does not endure unnecessary pain or distress.

Live Strandings Do’s and Don’ts

Well-intentioned public involvement can sometimes complicate response to a live stranding. Approaching a distressed animal puts human safety at risk and is illegal under the Marine Mammal Protection Act9. Attempting to push a stranded animal back into the water can increase stress, risk injury or drowning, or lead to re-stranding.

Before responders arrive, the public can help by keeping noise levels low, keeping pets away, and following instructions from authorities (Fig. 4). Once on site, response teams may establish boundaries to protect both people and the animal. Community support, such as providing access to private beaches or properties, supplying water or food, or assistance when requested, can play an important role in a smooth response.

Figure 4. Do’s and don’ts for live stranded marine mammals. (Katharina J. Peters and Rebecca M. Boys)

Step 3 – Performing a Necropsy

A critical step after a marine mammal stranding is performing the necropsy to gain further insight into the cause of death. Preliminary information about the stranding itself is recorded, followed by identifying species and sex. Photos are taken of each part of the animal and measurements are collected to obtain morphometric data. A careful external examination is required to identify any signs of human interaction (i.e., entanglement, boat strike) or evidence of disease (i.e., skin lesions, blisters).

Upon opening the animal, each organ is examined and noted for abnormalities. Samples are collected from each organ for histopathology (to identify disease), virology, parasitology, or contaminant analysis. The number of samples that can be collected is influenced by how far along in the decomposition process the carcass is in, and how safely accessible the animal is (e.g., based on tides, daylight, weather).

Step 4 – Identifying Cause of Death

Determining the cause of death for stranded marine mammals is not always possible and rarely straightforward. But broadly, the causes of mortality fall into two categories: environmental factors and anthropogenic factors.

Environmental factors of mortality

Infectious and non-infectious diseases are among the leading causes of marine mammal mortality10. These include bacterial, viral, fungal, and parasitic infections that can affect multiple organ systems, impair feeding, and ultimately lead to emaciation or starvation11-13. Some pathogens, like cetacean morbillivirus and brucellosis, have caused large-scale mortality events and raise concerns for human health, highlighting the need for global monitoring14,15.

Marine mammals are also exposed to pollutants that bioaccumulate in marine ecosystems, including legacy contaminants such as DDT, PCBs, and heavy metals16-19. High contaminant loads have been linked to immunosuppression, increased disease susceptibility, reproductive impairment, endocrine disruption, and neoplasia20-23.

Harmful algal blooms (HABs) and the toxins they produce, such as domoic acid, have also caused mass mortality events in pinnipeds, sea otters, and cetaceans24-27. As HABs increase in frequency and intensity worldwide, they represent a growing threat to both marine mammals and ecosystem health.

Anthropogenic factors of mortality

In addition to natural and environmental causes, many marine mammal strandings are directly linked to human activities in the ocean. Collisions with vessels can result in severe injury or death and are often identified in stranded animals by propeller wounds or evidence of blunt force trauma observed during necropsy. While large, fast-moving ships are responsible for many fatalities involving large whales28,29, smaller recreational vessels also pose substantial risks to coastal species such as bottlenose dolphins and manatees30,31.

Entanglement in fishing gear is also a major source of human-caused mortality for marine mammals worldwide, affecting thousands of animals each year. Smaller species may drown from heavy gear, while large whales can become entangled and drag gear for weeks or months, leading to exhaustion, impaired feeding, infection, and drowning32.

Why do Marine Mammal Strandings Matter?

Marine mammal strandings play a critical role in monitoring ecosystem health. Through strandings and subsequent necropsies, scientists can identify the primary causes of mortality and detect patterns that would otherwise remain hidden in the open ocean. Marine mammals are particularly effective sentinels because they are long-lived, occupy mid- to high-trophic levels, and accumulate pollutants and toxins in their tissues, often providing early warning signs of emerging environmental stressors10.

Multiple stressors from both environmental and human-related threats can compound on a species, resulting in population declines. Continued monitoring through surveys on living animals and information gathered from stranded animals help provide data on what threats are most critical to inform conservation and management decisions and protect both marine ecosystems and human communities.

Preventing Strandings

Many efforts are being made to reduce mortality in marine mammals stemming from direct human impacts. NOAA has established regulations to implement speed restrictions in certain places and times to reduce lethal collisions. There is also a Whale Alert App that boaters can use to see where whales have recently been detected and avoid those areas. Remaining alert and vigilant on the water and transiting slowly in areas where marine mammals may be present can greatly reduce the risk of vessel strikes.

A significant amount of work worldwide is being done to better understand whale entanglements and develop solutions to reduce these events. In the GEMM Lab, Project OPAL was developed to identify co-occurrence between whales and fishing effort in Oregon to reduce entanglement risk. This collaborative project brings together scientists, managers from the Oregon Department of Fish and Wildlife, the commercial Oregon Dungeness crab fishery, and environmental nonprofits to discuss research methods and findings, and develop best practices and regulations to limit risk of entanglement while also ensuring a vibrant and profitable fishery.

If You Come Across a Stranded Marine Mammal

If you see a marine mammal stranding in Oregon, please make your first call to (541) 270-6830 to alert trained responders quickly. If you are in other U.S. regions, the hotlines can be found here.

References

  1. NOAA Fisheries. (2025). Experts Euthanize Oregon Humpback Whale After Unsuccessful Attempt to Free it from Beach. NOAA. https://www.fisheries.noaa.gov/feature-story/experts-euthanize-oregon-humpback-whale-after-unsuccessful-attempt-free-it-beach
  2. Geraci, J. R. & Lounsbury, V. J. (2005). Marine Mammals Ashore: A Field Guide for Strandings, 2nd Edition. National Aquarium in Baltimore.
  3. NOAA Fisheries. (2024). National Marine Mammal Stranding Response Network. NOAA. https://www.fisheries.noaa.gov/national/marine-life-distress/national-marine-mammal-stranding-response-network
  4. NOAA Fisheries (2023). John H. Prescott Marine Mammal Rescue Assistance Grant Program | NOAA Fisheries. NOAA. https://www.fisheries.noaa.gov/grant/john-h-prescott-marine-mammal-rescue-assistance-grant-program
  5. Neves, M. C., Neto, H. G., Cypriano-Souza, A. L., da Silva, B. M. G., de Souza, S. P., Marcondes, M. C. C., & Engel, M. H. (2020). Humpback Whale (Megaptera novaeangliae) Resighted Eight Years After Stranding. Aquatic Mammals, 46(5), 483–487.
  6. Mazzoil, M. S., McCulloch, S. D., Youngbluth, M. J., Kilpatrick, D. S., Murdoch, E. M., Mase-Guthrie, B., Odell, D. K., & Bossart, G. D. (2008). Radio-Tracking and Survivorship of Two Rehabilitated Bottlenose Dolphins (Tursiops truncatus) in the Indian River Lagoon, Florida. Aquatic Mammals, 34(1), 54–64.
  7. McHugh, K. A., Barleycorn, A. A., Allen, J. B., Bassos-Hull, K., Lovewell, G., Boyd, D., Panike, A., Cush, C., Fauquier, D., Mase, B., Lacy, R. C., Greenfield, M. R., Rubenstein, D. I., Weaver, A., Stone, A., Oliver, L., Morse, K., & Wells, R. S. (2021). Staying Alive: Long-Term Success of Bottlenose Dolphin Interventions in Southwest Florida. Frontiers in Marine Science, 7.
  8. Moore, M., Early, G., Touhey, K., Barco, S., Gulland, F., & Wells, R. (2007). Rehabilitation And Release Of Marine Mammals In The United States: Risks And Benefits. Marine Mammal Science, 23(4), 731–750.
  9. NOAA Fisheries. (2025a). Do Not Move Stranded Whales, Dolphins, or Porpoises. NOAA. https://www.fisheries.noaa.gov/marine-life-distress/do-not-move-stranded-whales-dolphins-or-porpoises
  10. Bossart, G. D. (2010). Marine Mammals as Sentinel Species for Oceans and Human Health. Veterinary Pathology, 48(3), 676–690.
  11. Bogomolni, A., Pugliares, K., Sharp, S., Patchett, K., Harry, C., LaRocque, J., Touhey, K., & Moore, M. (2010). Mortality trends of stranded marine mammals on Cape Cod and southeastern Massachusetts, USA, 2000 to 2006. Diseases of Aquatic Organisms, 88, 143–155.
  12. McFee, W. E., & Lipscomb, T. P. (2009). Major Pathologic Findings And Probable Causes Of Mortality In Bottlenose Dolphins Stranded In South Carolina From 1993 To 2006. Journal of Wildlife Diseases, 45(3), 575–593.
  13. Sanderson, C. E., & Alexander, K. A. (2020). Unchartered waters: Climate change likely to intensify infectious disease outbreaks causing mass mortality events in marine mammals. Global Change Biology, 26(8), 4284–4301.
  14. Taubenberger, J. K., Tsai, M.m Krafft, A. E., Lichy, J. H., Reid, A. H., Schulman, F. Y. & Lipscomb, T. P. (1996). Two morbilliviruses implicated in bottlenose dolphin epizootics. Emerging Infectious Diseases, 2(3), 213-216.
  15. Whatmore, A. M., Dawson, C. E., Groussaud, P., Koylass, M. S., King, A. C., Shankster, S. J., Sohn, A. H., Probert, W. S., & McDonald, W. L. (2008). Marine mammal Brucella genotype associated with zoonotic infection. Emerging Infectious Diseases, 14(3), 517-518.
  16. Becker, P. R. (2000). Concentration of Chlorinated Hydrocarbons and Heavy Metals in Alaska Arctic Marine Mammals. Marine Pollution Bulletin, 40(10), 819–829.
  17. Fair, P. A., Mitchum, G., Hulsey, T. C., Adams, J., Zolman, E., McFee, W., Wirth, E., & Bossart, G. D. (2007). Polybrominated Diphenyl Ethers (PBDEs) in Blubber of Free-Ranging Bottlenose Dolphins (Tursiops Truncatus) from Two Southeast Atlantic Estuarine Areas. Archives of Environmental Contamination and Toxicology, 53(3), 483–494.
  18. Lee, K., Alava, J. J., Cottrell, P., Cottrell, L., Grace, R., Zysk, I., & Raverty, S. (2022). Emerging Contaminants and New POPs (PFAS and HBCDD) in Endangered Southern Resident and Bigg’s (Transient) Killer Whales (Orcinus orca): In Utero Maternal Transfer and Pollution Management Implications. Environmental Science & Technology, 57(1), 360–374.
  19. Noël, M., & Brown, T. M. (2021). Contaminants as a Conservation Threat to Marine Mammals. Wildlife Biodiversity Conservation, 401–420.
  20. Colborn, T., & Smolen, M.J.(2003). Cetaceans and contaminants. In Vos, J. G., Bossart, G. D., Fournier, M., & O’Shea, T. (Eds.). Toxicology of Marine Mammals (pp. 291-232). Taylor & Francis, London.
  21. Murphy, S., Pierce, G. J., Law, R. J., Bersuder, P., Jepson, P. D., Learmonth, J. A., Addink, M., Dabin, W., Santos, M. B., Deaville, R., Zegers, B. N., Mets, A., Rogan, E., Ridoux, V., Reid, R. J., Smeenk, C., Jauniaux, T., López, A., Alonso Farré, J. M., & González, A. F. (2010). Assessing the effect of persistent organic pollutants on reproductive activity in common dolphins and harbour porpoises. Journal of Northwest Atlantic Fishery Science, 42, 153–173.
  22. Ross, P. S. (2002). The Role of Immunotoxic Environmental Contaminants in Facilitating the Emergence of Infectious Diseases in Marine Mammals. Human and Ecological Risk Assessment: An International Journal, 8(2), 277–292.
  23. Tanabe, S. (2002). Contamination and toxic effects of persistent endocrine disrupters in marine mammals and birds. Marine Pollution Bulletin, 45(1-12), 69–77.
  24. Fire, S. E., Wang, Z., Byrd, M., Whitehead, H. R., Paternoster, J., & Morton, S. L. (2011). Co-occurrence of multiple classes of harmful algal toxins in bottlenose dolphins (Tursiops truncatus) stranding during an unusual mortality event in Texas, USA. Harmful Algae, 10(3), 330–336.
  25. Häussermann, V., Gutstein, C. S., Bedington, M., Cassis, D., Olavarria, C., Dale, A. C., Valenzuela-Toro, A. M., Perez-Alvarez, M. J., Sepúlveda, H. H., McConnell, K. M., Horwitz, F. E., & Försterra, G. (2017). Largest baleen whale mass mortality during strong El Niño event is likely related to harmful toxic algal bloom. PeerJ, 5, e3123.
  26. Miller, M. A., Kudela, R. M., Mekebri, A., Crane, D., Oates, S. C., Tinker, M. T., Staedler, M., Miller, W. A., Toy-Choutka, S., Dominik, C., Hardin, D., Langlois, G., Murray, M., Ward, K., & Jessup, D. A. (2010). Evidence for a Novel Marine Harmful Algal Bloom: Cyanotoxin (Microcystin) Transfer from Land to Sea Otters. PLoS ONE, 5(9), e12576.
  27. Smith, J., Cram, J. A., Berndt, M. P., Hoard, V., Shultz, D., & Deming, A. C. (2023). Quantifying the linkages between California sea lion (Zalophus californianus) strandings and particulate domoic acid concentrations at piers across Southern California. Frontiers in Marine Science, 10.
  28. Laist, D. W., Knowlton, A. R., Mead, J. G., Collet, A. S., & Podesta, M. (2001). COLLISIONS BETWEEN SHIPS AND WHALES. Marine Mammal Science, 17(1), 35–75.
  29. Schoeman, R. P., Patterson-Abrolat, C., & Plön, S. (2020). A Global Review of Vessel Collisions With Marine Animals. Frontiers in Marine Science, 7.
  30. Calleson, C., & Kipp Frohlich, R. (2007). REVIEW: Slower boat speeds reduce risks to manatees. Endangered Species Research, 3, 295–304.
  31. Wells, R. S., & Scott, M. D. (1997). Seasonal Incidence Of Boat Strikes On Bottlenose Dolphins Near Sarasota, Florida. Marine Mammal Science, 13(3), 475–480.
  32. Cassoff, R., Moore, K., McLellan, W., Barco, S., Rotstein, D., & Moore, M. (2011). Lethal entanglement in baleen whales. Diseases of Aquatic Organisms, 96(3), 175–185.

How Humans and Cetaceans Shape Each Other

Marc Rams i Rios, PhD Student, Oregon State University Department of Fisheries, Wildlife, and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

When I moved to Oregon to begin my PhD, I pictured long days on the water watching gray whales feed and travel along the coast. That does happen, and it is as incredible as I imagined. But I have learned that studying cetaceans is about much more than observing whales. It is also about people: how cultures – past and present – perceive these animals and share space with them.

In addition to marine mammals, I have always loved history and geography. Now, as I start my work with the GRANITE Project in the GEMM Lab, I find myself thinking about how these relationships between humans and whales unfold across time and space. In this post, I want to share a few examples of how whales have shaped human traditions for hundreds, even thousands of years, across societies that have never crossed. Then I will discuss how our research fits into this larger picture of human–cetacean connections.

Our journey begins in India, where the Ganges River dolphin inhabits a river that millions of people consider sacred. Its presence has long been linked to the health of the river, giving the species spiritual and cultural significance. Over the past century, the river’s ecological integrity has declined due to pollution, altered flow, and habitat disturbances, and this has caused the dolphin population to diminish1, 2. Conservation efforts that improve water quality, restore natural flow, and reduce disturbances not only help the dolphin recover but also protect the river and the human communities that rely on it1, 2. In this way, cultural reverence for the dolphin drives conservation measures that benefit both people and ecosystems1, 2.

© WWF Mohd Shahnawaz Khan

From there we move to Aotearoa, New Zealand, where Māori tradition speaks of tohorā, or whales, as guardians and ancestors3. They appear in ancestral stories as guides and protectors, and whale strandings have historically brought communities together in collective response. The Māori principles of kaitiakitanga, or guardianship, continue to shape marine conservation decisions today, guiding policies that integrate ecological and cultural values4. Here, whales are not seen as resources. They are part of a living genealogy that binds people to the sea and the life it sustains. In fact, team members of the SAPPHIRE project in the GEMM lab frequently engage with multiple iwi (Māori tribes) across Aotearoa through hui (meetings) where knowledge, stories, and culture are shared about blue whales and their ecosystem.

Traveling nearly to the antipodes, we arrive on the Atlantic coast of Brazil, in the town of Laguna, where an extraordinary partnership has endured for centuries. Artisanal fishers work alongside bottlenose dolphins, who drive schools of fish toward the shore and signal the right moment to cast the nets5, 6, 7. This cooperation benefits both species, and the knowledge behind it is passed down through generations of humans and dolphins through observation and shared practice5, 6, 7. It is a powerful example of how species can learn from one another, creating connections that challenge the idea of humans and wildlife as competitors and showing the potential for collaboration across species5, 6, 7. The LABIRINTO Lab in MMI has studied this interspecific relationship for decades, helping us learn about the patterns and endurance of these cultures.

PELD-SELA: Long-term ecological project on the Laguna Estuarine System and Adjacent Areas Projects. (n.d.). https://thelabirinto.com/projects1/

At the top of the Americas, in the Arctic, Inuit communities have hunted bowhead whales for thousands of years. These hunts are not only a source of food but also form the foundation of cultural identity and social life8. Knowledge of the ice, weather, and whale behavior is passed down through generations, and the hunt itself is embedded in ceremonies and practices that sustain the community8. Today, these traditions continue under strict quotas set through international agreements, carefully balancing cultural continuity with conservation9. The MMBEL lab in MMI studies the communication and ecology of bowhead whales to support the survival of this iconic species and the culture of Inuit people.

Emory Kristoff, National Geographic

Finally, our journey brings us to Oregon, where gray whales feed along a coastline rich with reefs, kelp beds, and sandy bottoms. These waters support a variety of human activities, from commercial fishing to recreation, creating risks such as entanglement, vessel strikes, and disturbance10, 11. Even well-intentioned actions like whale watching can cause harm if not carefully managed12, 13. Around the world, many communities have shifted from whaling to whale watching, transforming former hunting grounds into tourism destinations. While this is a positive change, it still requires monitoring. Noise can stress whales, boats can disrupt their behavior, and too much interaction can alter natural feeding and social patterns12, 13. In Oregon, research on gray whale habitat use and feeding home ranges helps inform management and conservation14.

Tradewind Charters Whale Watching and Fishing

This is where project GRANITE, Gray whale Response to Ambient Noise Informed by Technology and Ecology, comes in15. The project studies how whales respond to human activities by using drones to monitor health and behavior, photo-ID to track individuals, prey mapping to understand feeding choices, and acoustic recorders to capture the soundscape15, 16, 17. Equally important is collaborating directly with fishers and resource managers to reduce risks and develop solutions that benefit both whales and people. Healthy whale populations support communities too, through ecotourism, cultural continuity, education, and the ecological services whales provide. Conservation is reciprocal: caring for whales strengthens the ocean systems that sustain us all.

The tools and techniques developed by GRANITE, including drones, acoustic monitoring, and prey mapping, are not limited to Oregon. They can be applied globally, contributing to the protection of cetaceans in diverse habitats15. In this way, Oregon becomes more than the final stop on our tour. It is a place where centuries of human–whale relationships, lessons from around the world, and modern science converge. These examples across the world remind us that conservation is about more than preventing harm. It is about fostering a future where humans and whales thrive together, as they have shared the ocean for millennia.

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References

1 Sinha, R. K., & Kannan, K. (2014). Ganges river dolphin: An overview of biology, ecology, and conservation status in India. AMBIO, 43(8), 1029–1046. https://doi.org/10.1007/s13280-014-0534-7

2 Braulik, G., Atkore, V., Khan, M. S., & Malla, S. (2021). Review of scientific knowledge of the Ganges river dolphin. WWF. https://riverdolphins.org/wp-content/uploads/2021/07/Ganges-River-dolphin-Scientific-Knowledge-Review-July2021.pdf

3 Taonga, N. Z. M. for C. and H. T. M. (n.d.). Whales in Māori tradition. Teara.govt.nz. https://teara.govt.nz/en/te-whanau-puha-whales/page-1

4 McAllister, T., Hikuroa, D., & Macinnis‑Ng, C. (2023). Connecting science to Indigenous knowledge: Kaitiakitanga, conservation, and resource management. New Zealand Journal of Ecology, 47(1), 3521. https://doi.org/10.20417/nzjecol.47.3521

5 Simões‑Lopes, P. C., Fabián, M. E., & Menegheti, J. O. (1998). Dolphin interactions with the mullet artisanal fishing on southern Brazil: A qualitative and quantitative approach. Revista Brasileira de Zoologia, 15(3), 709–726. https://doi.org/10.1590/S0101-81751998000300008

6 Daura Jorge, F. G., Cantor, M., Ingram, S. N., Lusseau, D., & Simões Lopes, P. C. (2012). The structure of a bottlenose dolphin society is coupled to a unique foraging cooperation with artisanal fishermen. Biology Letters, 8(5), 702–705. https://doi.org/10.1098/rsbl.2012.0174

7 Cantor, M., Farine, D. R., & Daura‑Jorge, F. G. (2023). Foraging synchrony drives resilience in human–dolphin mutualism. Proceedings of the National Academy of Sciences, 120(6), e2207739120. https://doi.org/10.1073/pnas.2207739120

8 Jensen, A. M. (2012). The material culture of Iñupiat whaling: An ethnographic and ethnohistorical perspective. Arctic Anthropology, 49(2), 143–161. https://doi.org/10.1353/arc.2012.0020

9 Description of the USA Aboriginal Subsistence Hunt: Alaska. (n.d.). Iwc.int. https://iwc.int/management-and-conservation/whaling/aboriginal/usa/alaska

10 Derville, S., Buell, T. V., Corbett, K. C., Hayslip, C., & Torres, L. G. (2023). Exposure of whales to entanglement risk in Dungeness crab fishing gear in Oregon, USA. Biological Conservation, 281, 109989. https://doi.org/10.1016/j.biocon.2023.109989

11 Silber, G. K., Weller, D. W., Reeves, R. R., Adams, J. D., & Moore, T. J. (2021). Co‑occurrence of gray whales and vessel traffic in the North Pacific Ocean. Endangered Species Research, 44, 177–201. https://doi.org/10.3354/esr01093

12 Sullivan, F. A., & Torres, L. G. (2018). Assessment of vessel disturbance to gray whales to inform sustainable ecotourism. Journal of Wildlife Management, 82(5), 896–905. https://doi.org/10.1002/jwmg.21462

13 Sprogis, K. R., Videsen, S., & Madsen, P. T. (2020). Vessel noise levels drive behavioural responses of humpback whales with implications for whale‑watching. eLife, 9, e56760. https://doi.org/10.7554/eLife.56760

14 Lagerquist, B. A., Palacios, D. M., Winsor, M. H., Irvine, L. M., Follett, T. M., & Mate, B. R. (2019). Feeding home ranges of Pacific Coast Feeding Group gray whales. Journal of Wildlife Management, 83(4), 925–937. https://doi.org/10.1002/jwmg.21642

15 GRANITE: Gray whale Response to Ambient Noise Informed by Technology and Ecology | Marine Mammal Institute | Oregon State University. (n.d.). Mmi.oregonstate.edu. https://mmi.oregonstate.edu/gemm-lab/granite-gray-whale-response-ambient-noise-informed-technology-ecology

16 Pirotta, E., Bierlich, K. C., New, L., Bird, C. N., Fernandez Ajó, A., Hildebrand, L., Buck, C. L., Hunt, K. E., Calambokidis, J., & Torres, L. G. (2025). Body size, nutritional state and endocrine state are associated with calving probability in a long‑lived marine species. Journal of Animal Ecology. Advance online publication. https://doi.org/10.1111/1365-2656.70068

17 Bierlich, K. C., Kane, A., Hildebrand, L., Bird, C. N., Fernandez Ajó, A., Stewart, J. D., Hewitt, J., Hildebrand, I., Sumich, J., & Torres, L. G. (2023). Downsized: Gray whales using an alternative foraging ground have smaller morphology. Biology Letters, 19(7), 20230043. https://doi.org/10.1098/rsbl.2023.0043

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Why the precautionary principle matters for marine mammal conservation

Lindsay Wickman, Postdoctoral Scholar, Oregon State University Department of Fisheries, Wildlife, and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

This summer, Rep. Nick Begich of (R-AK), submitted a draft bill that proposes to roll back key features of the 1972 U.S. Marine Mammal Protection Act (MMPA). The MMPA has been the centerpiece legislation protecting whales, dolphins, sea otters, manatees, polar bears and seals for over 50 years, bringing many species back from the brink of extinction and setting a benchmark that has been replicated worldwide. Among the changes proposed, the draft bill explicitly bars the use of the precautionary principle in marine mammal management. For example, the draft bill includes these changes:

  • changing wording from “has the potential to injure/disturb” to “injures or disturbs” when considering threats that need to be mitigated.
  • instead of managing marine mammal populations to “result in maximum productivity”, the draft bill would manage species at the size “necessary to support the continued survival”.

The draft bill also includes changes to how allowable levels of injury and mortality to marine mammal populations (called a “take”) in the MMPA are calculated. Until now, these take levels were calculated using safety factors that correct for scientific uncertainty and bias. The proposal removes these safety factors, which would essentially increase the number of allowable takes from each population before management intervention is required. The proposed changes also require a much higher burden of proof before populations can be considered “depleted” or “strategic”, which are identifiers that trigger conservation action.

 Proponents of the draft bill say the current MMPA has been too precautionary, unnecessarily increasing burdens on fishers and other resource users. Here, I argue that the precautionary principle is not a subjective judgement that favors marine mammals over people’s livelihoods. Instead, it is a rational decision-making tool, essential for making management decisions when information is uncertain.

A humpback whale (Megaptera novaeangliae) surfaces during a recent research survey. Humpback whales along the U.S. West Coast have increased in abundance since the end of commercial whaling and MMPA protections. Imagery collected under research permit #27426 issued to MMI.

What is the precautionary principle?

In practice, it means that a lack of data or uncertainty in statistical estimates or trends should not be used as an excuse for inaction in the face of a valid threat (Raffensperger and Tickner, 1999). Instead, decision-makers should incorporate “safety factors” that account for limited knowledge or imperfect science. As said by Holt and Talbot (1978), “the magnitude of the safety factor should be proportional to the magnitude of risk.” So, if the goal is to prevent extinction, severely depleted populations may require bigger safety factors than healthy populations.

How does the U.S. MMPA apply the precautionary principle? 

During the first few decades the MMPA, actions to protect marine mammals were primarily reactionary, in response to highly publicized issues like the dolphin-tuna problem (Taylor et al., 2000). Conservation actions were supposed to be triggered when scientists detected a declining trend in a population’s abundance, but obtaining precise estimates of population size is notoriously difficult for marine mammals. The amount of data required to prove a population was declining due to human activities was so high that protection was continually stalled due to uncertainty in statistical trends (e.g., Marine Mammal Commission 1982; Wade 1993; Taylor et al., 2000).

In 1994, the U.S. MMPA was amended, implementing a new way to determine which marine mammal populations were at risk. Instead of requiring a statistical trend in population abundance, the new method calculates the number of sustainable takes without putting the population at risk of decline. The 1994 amendments also explicitly applied the precautionary principle by incorporating safety factors into this calculation of this number of allowable takes, known as the Potential Biological Removal (PBR; Wade 1998), which increases the likelihood that the management goals stated by the MMPA are achieved (Taylor et al., 2000). 

Three reasons why the precautionary principle matters:

1. It accounts for uncertainty and potential bias

Consider air travel for a moment: Given the uncertainty in the amount of time it takes to arrive at the airport (e.g., traffic, parking) and the unknown possibilities for extra delays once there (e.g., security), most travelers shoot for airport arrival times significantly earlier than the flight boards.  However, what if instead of an exact flight time, you are told the plane leaves sometime between 9 and 11 am? Also, although you have some experience travelling, you have never used this particular airport, and you have no idea how long security and check-in might take. Given these hypothetical circumstances, how would you plan your travel?

When applying marine mammal science to management goals, decision-makers must contend with a similarly uncertain set of information. Marine mammals are wide-ranging and spend most of their lives underwater, making them particularly challenging to study. It is impossible to get exact estimates of population size for these animals, and even the best designed research produces abundance estimates with significant levels uncertainty (e.g., Taylor et al., 2000; Taylor et al. 2007). After decades of researching marine mammals, we also still have significant knowledge gaps about their population dynamics, space-use, and behaviors.

Currently, the MMPA accounts for scientific uncertainty by using minimum estimated population size (the lower 20th percentile) when calculating sustainable levels of human takes (Wade 1998; Taylor et al. 2000). This safety factor makes it more likely that calculations of allowable takes are at or below safe levels (Wade 1998; Taylor et al. 2000).

Relating back to the airport example, if you were told your flight could leave between 9 and 11 am, using minimum population size (instead of the maximum or center of the estimate) is analogous to planning for the flight to leave closer to 9 am. However, you still need to add in time for extra factors that may cause other possible delays in addition to the uncertain departure time.

So, in addition to minimum population size, the MMPA also uses another safety factor in its calculation of allowable takes, called the recovery factor (FR). FR scales the number of allowable takes relative to the level of risk to the population and the potential for biased or uncertain information (Wade 1998; Taylor et al. 2000).  A lower FR is given to depleted, high risk populations, while FR can be increased for well-studied populations at lower risk (Wade 1998; Taylor et al. 2000). In the travel analogy, FR is the amount of padding needed to ensure a passenger makes their flight, accounting for potentially unknown security lines and traffic.

2. It incentivizes the public and industry to collect more data to “fine-tune” management

The more experienced you are with a particular airport and the more certain you are of the departure time, the more confident you can be in your travel plans. If you know the plane leaves at 10 am, and security takes 15 minutes, you don’t need to add nearly as much extra travel time as if your travel details were more uncertain.

Importantly, as the scientific knowledge of a population increases, the magnitude of the safety factors in the calculation of allowable mortalities decreases. For example, as the number of surveys of a population increases and an abundance estimate gets more precise, the range of the abundance estimate gets smaller. So, getting a more precise abundance estimate is like changing your uncertain flight time from being between 9 – 11 am, to being between 9:30 – 10 am. While you still have some uncertainty, you can be confident that leaving a little later than originally planned would be ok.

Since better knowledge results in more targeted management, both the public and industry are motivated to invest in continued research. Fine-tuning management means that necessary precautions can be kept, but unnecessary burdens on industries are removed. Ultimately, the strategy of a precautionary approach is to “act now, fine-tune later,” instead of “delay action until we get detailed information.” In addition to potentially delaying urgent action, the latter approach also disincentivizes industry to invest in research or develop solutions. As explained below, delaying conservation due to uncertainty has led to past pitfalls in marine mammal conservation, necessitating the need for a more proactive approach.

3. It prevents unnecessary delays in conservation action

If you had an important flight to catch on Wednesday, but did not know the departure time, would you decide to not go to the airport at all? Would it be worth it to just get to the airport early, or would you wait at home for more information, but at the risk of missing your flight?

The choice to not act at all in the face of uncertain data is inherently risky. For the first couple of decades of the MMPA, managers attempted to prove a population was declining before conservation action could be taken. The problem is, determining population trends of marine mammals with any certainty can take decades (Taylor and Gerrodette, 1993; Wade 1993; Taylor et al., 2000). In the case of some species, by the time scientists have the statistical power to detect a trend, the population could already be in a catastrophic decline. For example, in the case of eastern tropical Pacific dolphins killed as bycatch by the tuna industry during the 1970s, proving their population decline led to a 14-year protection delay from the first abundance estimate of the population (Wade et al., 1994; Taylor et al., 2000).

The purpose of the 1994 MMPA amendments was to correct for these unnecessary delays that required extensive amounts of data (Taylor et al. 2000). Instead of requiring population trend data, the MMPA now uses values that are much easier to obtain — population size and maximum population growth rates (Wade 1998). From these, the number of individuals that can sustainably be removed from the population (PBR) can be calculated. This approach is a much faster and simpler method, allowing for quick action if estimated mortality (e.g., numbers of animals killed or injured) is higher than this calculated threshold (PBR).

Lastly, the precautionary principle assumes that if a threat is valid, it should be considered, even if the effects are not 100% proven yet. This approach is essential for marine mammals, where anthropogenic injuries and mortality are not always easily detected or recorded. In the case of ship strikes and fisheries entanglement, many individuals disappear before their deaths or injuries are recorded (e.g., Cassoff et al., 2011; Pace et al. 2021). Other threats, like the effects of sound and chemical pollution, may require long-term monitoring to fully understand their population-level impacts. By using language like “has the potential to injure,” management can be implemented more proactively, allowing for research to continue, but not at the detriment of population health during the lengthy time it can take to establish statistical certainty.

Final thoughts

The precautionary principle is a way of dealing with the fact that good science can cost precious time. Results rarely give “yes or no” answers and clear-cut solutions. Instead, decision-makers must weigh study design, statistical power, and the precision (i.e., uncertainty) of scientific findings. The precautionary principle provides a framework for how to effectively use science to make decisions, increasing the likelihood that management plans meet their goals.

If this blog makes you concerned about the future of the precautionary principle in the U.S. MMPA:

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References

Cassoff, R.M., Moore, K.M., McLellan, W.A., Barco, S.G., Rotstein, D.S., Moore, M.J. (2011). Lethal entanglement in baleen whales. Diseases of Aquatic Organisms, 96: 175– 185.

Holt, S. J., and L. M. Talbot. (1978). New principles for the conservation of wild living resources. Wildlife Monographs, 59.

Marine Mammal Commission. (1982). Marine Mammal Commission annual report to Congress. Bethesda, Maryland.

Pace, R.M., Williams, R., Kraus, S.D., Knowlton, A.R., Pettis, H.M. (2021). Cryptic mortality of North Atlantic right whales. Conservation Science and Practice, 3: e346.

Raffensperger C, Tickner J, eds. (1999). Protecting Public Health and the Environment: Implementing the Precautionary Principle. Washington, DC: Island Press.

Taylor, B. L., & Gerrodette, T. (1993). The Uses of Statistical Power in Conservation Biology: The Vaquita and Northern Spotted Owl. Conservation Biology, 7(3), 489–500.

Taylor, B. L., Wade, P. R., de Master, D. P., & Barlow, J. (2000). Incorporating uncertainty into management models for marine mammals. Conservation Biology, 14(5), 1243–1252.

Taylor, B. L., Martinez, M., Gerrodette, T., Barlow, J., & Hrovat, Y. N. (2007). Lessons From Monitoring Trends in Abundance of Marine Mammals. Marine Mammal Science, 23(1), 157–175.

Wade, P. R. (1993). Estimation of historical population size of the eastern spinner dolphin (Stenella longirostris orientalis). Fishery Bulletin, United States 91:775–787.

Wade, P. R. (1994). Abundance and population dynamics of two eastern Pacific dolphins, Stenella attenuata and Stenella longirostris orientalis. Ph.D. dissertation. Scripps Institution of Oceanography, University of California, San Diego.

Wade, P. R. (1998). Calculating limits to the allowable human-caused mortality of cetaceans and pinnipeds. Marine Mammal Science, 14(1), 1–37.

New GEMM Lab study indicates troubled times for PCFG gray whales

Dr. Enrico Pirotta (CREEM, University of St Andrews) and Dr. Leigh Torres (GEMM Lab, MMI, OSU)

The health of animals affects their ability to survive and reproduce, which, in turn, drives the dynamics of populations, including whether their abundance trends up or down. Thus, understanding the links between health and reproduction can help us evaluate the impact of human activities and climate change on wildlife, and effectively guide our management and conservation efforts. In long-lived species, such as whales, once a decline in population abundance is detected, it can be too late to reverse the trend, so early warning signals are needed to indicate how these populations are faring.

We worked on this complex issue in a study that was recently published in the Journal of Animal Ecology. In this paper, we developed a new statistical approach to link three key components of the health of a Pacific Coast Feeding Group (PCFG) gray whale (namely, its body size, body condition, and stress levels) to a female’s ability to give birth to a calf. We were able to inform these metrics of whale health using an eight-year dataset derived from the GRANITE project of aerial images from drones for measurements of body size and condition, and fecal samples for glucocorticoid hormone analysis as an indicator of stress. We combined these data with observations of females with or without calves throughout the PCFG range over our study period.

We found that for a female to successfully have a calf, she needs to be both large and fat, as these factors indicate if the female has enough energy stored to support reproduction that year (Fig. 1). Remarkably, we also found indication that females with particularly high stress hormone levels may not get pregnant in the first place, which is the first demonstration of a link between stress physiology and vital rates in a baleen whale, to our knowledge.

Figure 1. Taken from Pirotta et al. (2025), Fig. 5. Combined relationship of PCFG gray whale length and nutritional state (combination of body size and condition) in the previous year with calving probability, colored by whether the model estimated an individual to have calved or not at a given reproductive opportunity.

Our study’s findings are concerning given our previous research indicating that gray whales in this PCFG sub-group have been growing to shorter lengths over the last couple of decades (Pirotta et al. 2023), are thinner than animals in the broader Eastern North Pacific gray whale population (Torres et al, 2022), and show an increase in stress-related hormones when exposed to human activities (Lemos et al, 2022; Pirotta et al. 2023). Furthermore, in our recent study we also documented that there are fewer young individuals than expected for a growing or stable population (Fig. 2), which can be an indicator of a population in decline since there may not be many individuals entering the reproductive adult age groups. Altogether, our results act as early warning signals that the PCFG may be facing a possible population decline currently or in the near future.

Figure 2. Taken from Pirotta et al. (2025), Fig. 1. Age structure diagram for 139 PCFG gray whales in our dataset. Each bar represents the number of individuals of a given age in 2023, with the color indicating the proportion of individuals of that age for which age is known (vs. estimated from a minimum estimate following Pirotta, Bierlich, et al., 2024). The red line reports a smooth kernel density estimate of the distribution.

These findings are sobering news for Oregon residents and tourists who enjoy watching these whales along our coast every summer and fall. We have gotten to know many of these whales so well – like Scarlett, Equal, Clouds, Lunita, and Pacman, who you can meet on our IndividuWhale website – that we wonder how they will adapt and survive as their once reliable habitat and prey-base changes. We hope our work sparks collective and multifaceted efforts to reduce impacts on these unique PCFG whales, and that we can continue the GRANITE project for many more years to come to monitor these whales and learn from their response to change.

This work exemplifies the incredible value of long-term studies, interdisciplinary methods, and effective collaboration. Through many years of research on this gray whale group, we have collected detailed data on diverse aspects of their behavior, ecology and life history that are critical to understanding their response to disturbance and environmental change, which are both escalating in the study region. We are incredibly grateful to the following members of the PCFG Consortium for contributing sightings and calf observation data that supported this study: Jeff Jacobsen, Carrie Newell, NOAA Fisheries (Peter Mahoney and Jeff Harris), Cascadia Research Collective (Alie Perez), Department of Fisheries and Oceans, Canada (Thomas Doniol-Valcroze and Erin Foster), Mark Sawyer and Ashley Hoyland, Wendy Szaniszlo, Brian Gisborne, Era Horton.

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References:

Lemos, Leila S., Joseph H. Haxel, Amy Olsen, Jonathan D. Burnett, Angela Smith, Todd E. Chandler, Sharon L. Nieukirk, Shawn E. Larson, Kathleen E. Hunt, and Leigh G. Torres. “Effects of Vessel Traffic and Ocean Noise on Gray Whale Stress Hormones.” Scientific Reports 12, no. 1 (2022): 18580. https://dx.doi.org/10.1038/s41598-022-14510-5.

Pirotta, Enrico, K. C. Bierlich, Leslie New, Lisa Hildebrand, Clara N. Bird, Alejandro Fernandez Ajó, and Leigh G. Torres. “Modeling Individual Growth Reveals Decreasing Gray Whale Body Length and Correlations with Ocean Climate Indices at Multiple Scales.” Global Change Biology 30, no. 6 (2024): e17366. https://doi.org/https://doi.org/10.1111/gcb.17366. https://onlinelibrary.wiley.com/doi/abs/10.1111/gcb.17366.

Pirotta, Enrico, Alejandro Fernandez Ajó, K. C. Bierlich, Clara N Bird, C Loren Buck, Samara M Haver, Joseph H Haxel, Lisa Hildebrand, Kathleen E Hunt, Leila S Lemos, Leslie New, and Leigh G Torres. “Assessing Variation in Faecal Glucocorticoid Concentrations in Gray Whales Exposed to Anthropogenic Stressors.” Conservation Physiology 11, no. 1 (2023). https://dx.doi.org/10.1093/conphys/coad082.

Torres, Leigh G., Clara N. Bird, Fabian Rodríguez-González, Fredrik Christiansen, Lars Bejder, Leila Lemos, Jorge Urban R, et al. “Range-Wide Comparison of Gray Whale Body Condition Reveals Contrasting Sub-Population Health Characteristics and Vulnerability to Environmental Change.” Frontiers in Marine Science 9 (2022). https://doi.org/10.3389/fmars.2022.867258. https://www.frontiersin.org/article/10.3389/fmars.2022.867258

The slow, but ever turning, cycles of science: a look under the hood of the scientific method

Dr. Clara Bird, Postdoctoral Scholar, OSU Department of Fisheries, Wildlife, and Conservation Sciences, GEMM Lab & LABIRINTO

Cycles can be found everywhere in nature and our lives. From tides and seasons to school years and art projects, we’re constantly experiencing cycles of varying scales. Spring on the Oregon coast brings several important cyclical events: more daylight, the oceanographic spring transition, and the return of our beloved gray whales – just to name a few. On my own personal scale, I’ve been thinking about the cycles we experience as scientists a lot lately, since I’ve recently transitioned out of graduate school and into my current position as a postdoctoral scholar.

Starting this new postdoc has been a bit jarring, as it’s felt like starting over. Even though I’m still working at the Marine Mammal Institute and still studying gray whales, I’ve been learning new skills, knowledge and theory, which pushes me to re-start the cycle of the scientific method, the process we follow in research (Figure 1). Broadly, we start by observing a system and asking a question about a potential pattern or event we see. We then come up with a hypothesis (or two or ten) to address our question(s). The next steps are to collect the data we need to answer our question(s) and test our hypotheses, analyze that data (i.e. run some statistical models), and draw some conclusions from the analysis results. While it seems quite linear, the process of data collection and analysis always leads to more questions than answers, and we inevitably start the cycle all over again.

Figure 1. Schematic depicting the scientific method

Throughout my scientific training I’ve gained experience in all these phases, but I’ve also learned just how many add-ons and do-overs there are in this process (Figure 2). Developing questions and hypotheses often requires a long and winding path through the literature, depending on how much you already know. These steps are often some of the first and biggest steps in graduate school. You need to learn as much as you can about the field and questions you are interested in, as this will inform what has already been done, where the knowledge gaps are, and the hypotheses you’re developing. For example, we often back up a hypothesis with references to studies that have answered our question in different systems. The learning curve is steep, and it’s important to not understate the work that goes into this phase. Early in my career, I remember hearing that “asking the good questions” is a critical skill for research. At the time that sounded like some vague, innate characteristic, and working to gain this ability felt ambiguous and overwhelming. I was absolutely wrong. Like most skills, knowing how to ask good questions is more about experience than intelligence. Here, experience is a combination of reading the literature and practice formulating questions based on the literature.

Figure 2. A more realistic version of the scientific method

Beyond this lesson, I also had to learn that what qualifies a question as “good” also depends on the funding source. In many research institutions, including those in the U.S., scientists are responsible for finding the funding to run their research projects. Funding a project includes salary for the scientists (e.g., professors, grad students, post docs), the cost of collecting and analyzing the data (e.g., travel, equipment, boat time), and the cost of publishing and sharing our findings (e.g., publication costs). The programs we solicit funding from often have their own priorities, so a big part of the research cycle is finding a funding source that is interested in the kinds of questions you want to ask and then adjusting your own questions and hypotheses to align with the funding source’s priorities and budget. The actual application includes writing a proposal where we (1) summarize all the background research justifying the novelty and value of the questions we want to ask and backing up our hypotheses and (2) describe how we plan on answering those questions. Funding is competitive and we typically apply multiple times before being successful. Furthermore, we often apply to multiple funding sources to support the same project. Since each source has its own focus, this ends up being an exercise in coming up with multiple ways to frame and justify a project.

Once we have funding (which can be years after the start of the cycle), we can finally start collecting, analyzing, and interpreting the data. But each of these steps has its own sub-cycles and complexities. Data collection can take years and involve all kinds of troubleshooting equipment issues, logistics, and methods. Depending on your question, data processing and analysis may involve developing your own method. For example, our lab asks a lot of questions about the morphology and body condition of whales. But before we could answer those questions, we first had to work out the best way to accurately measure whales from drone imagery while accounting for measurement uncertainty (read more here). This separate cycle of method development involved so many sub-projects and new software tools that Dr. KC Bierlich now leads the Marine Mammal Institute’s Center of Drone Excellence (CODEX).

Data analysis and interpretation brings us back to the literature review part of the cycle. But now we are looking for examples of how similar data have been analyzed previously and for studies to which we can compare our results. Then, after testing out different models and triple checking our analysis, we’re finally ready to share our findings. We share our results through conference presentations, publications (after the peer review cycle), outreach talks, and press releases that lead to media pieces and interviews.

In addition to the excitement of sharing our findings with the world, we’re simultaneously hyper-aware of all the caveats and limitations of our work. We’re always left with a long list of follow-up questions, thus starting the cycle again. From a zoomed-out perspective these results can form a clean, linear story. But zooming in reveals the reality of years and years of multiple overlapping cycles that have had to pass roadblocks and restart countless times. For example, after nine years for research, the GRANITE project has produced an impressive suite of results addressing questions related to Pacific Coast Feeding Group gray whale morphology, health, hormones, space use, and behavior. It took years of data collection, proposal writing, training, and multiple researchers working through their own project cycles to get here (and we’re not done).

Transitioning out of graduate school has meant expanding my scope of attention to multiple cycles running in parallel, re-starting the literature review process for new projects, and spending a lot more time in the proposal writing sub-cycle. While it’s felt overwhelming at times, I’ve also enjoyed digging into new topics and skills. It’s an interesting balance of experiencing the discomfort that comes with being a beginner while simultaneously drawing comfort from the knowledge that I’ve experienced this cycle before and know how to learn something new.

A consequence of learning the scientific process is growing accustomed to this cyclical nature. As scientists we know that it’s a slow process, that every result is just the start of a new cycle, and that future work building on a result may agree or disagree with the previous finding. But the way scientific findings are shared with the public doesn’t necessarily reflect the process. Catchy headlines and brief summaries often present findings as definitive and satisfying conclusions to a story. Behind those headlines are years of set up, data collection, analysis, and a suite of caveats that we want to dig into in the future. The results of any given study reflect our best current knowledge at that point in the cycle. By design, that knowledge will grow and change as we move forward.

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The blues are back in town: recap of the SAPPHIRE 2025 field season

By Dr. Dawn Barlow & Dr. Leigh Torres, OSU Department of Fisheries, Wildlife, and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

As the sun set on February 16th, the R/V Star Keys pulled into Wellington Harbour, marking the end of the 2025 SAPPHIRE field season. The crew and science team returned to shore after a packed, productive, and successful three weeks at sea studying the impacts of environmental change on blue whales and krill in the South Taranaki Bight, Aotearoa New Zealand.

A blue whale comes up for air in the South Taranaki Bight.

In stark contrast to the 2024 field season, which featured dense and seemingly endless layers of gelatinous salps in the water and no krill or blue whales in the South Taranaki Bight, the 2025 field season was filled with blue whales and krill. In our three weeks aboard our research vessel Star Keys this year, we observed 66 blue whales, most of which were lunge feeding at the surface on dense patches of krill. We also collected krill for on-board respiration experiments and to be frozen to measure their lengths, weights, and caloric content. We recovered two hydrophones that recorded blue whale calls for the past year, and replaced them with two more. We collected identification photos, skin and blubber tissue samples for genetic and hormone analysis, and flew drones over almost all whales we encountered to measure body condition and morphology. We conducted water column profiles to measure the oceanography of the region, and mapped the prey field as we surveyed using a scientific echosounder.

Map of our survey effort (gray tracklines), blue whale sightings (red circles), and hydrophone locations (purple stars).

Around the world, we are currently bearing witness to environmental change. Our survey last year in 2024 was a reminder of the challenges these blue whales face to survive and thrive in an increasingly unpredictable ocean. This year was a poignant example of the vibrant marine life that exists here in the South Taranaki Bight when ocean conditions align more closely with what is expected, and of the incredible resilience of these animals as they navigate changing waters. These contrasting conditions over multiple years are key to our understanding as we study the impacts of climate change on krill and blue whales through the SAPPHIRE project.

Drone image of a blue whale coming to the surface.

The fieldwork we do to collect these data is motivated by scientific questions, management needs, and fascination with this ecosystem. But ultimately, what makes fieldwork possible and memorable is the people. We are deeply grateful for the many partners on the SAPPHIRE project. The 2025 science team was made up of Leigh Torres, Dawn Barlow, KC Bierlich, Kim Bernard (Oregon State University), Mike Ogle, and Ros Cole (Department of Conservation). The outstanding crew of the R/V Star Keys (Western Work Boats), Josh Fowden, Dave Futter, and Jordy Maiden-Drum, kept us safe, sailing, fed, and happy for three intense weeks. We are also grateful for our shore support, including our colleagues at Cornell University’s Yang Center for Conservation Bioacoustics, NIWA, the Marine Mammal Institute at Oregon State University, and the University of Auckland. Importantly, we deeply appreciate our many stakeholders who help us share, learn, and make our findings meaningful, including the Department of Conservation, the people of Aotearoa, and iwi across our study region, especially Ngāruahine who hosted us at the Rangatapu Marae for a profound hui with a powerful pōwhiri and critical wānanga of knowledge sharing.

Drone image of a blue whale mom and calf pair.

Now the next phase of the work begins. We have many terabytes of data to process, analyze, interpret, and share. We will certainly have our hands full. But while we are at our computers back in Oregon, we will be holding the memories of this field season close: The brilliant turquoise glow of a blue whale just below the surface, the sound of the deep exhalation as the whale comes up for air, and the awe of looking into a blue whale’s eye as it engulfs a dense swarm of krill; The golden sunset lighting and moon rise over Cape Farewell, and Mount Taranaki towering over the blue waters of the South Taranaki Bight; The giddy exclamations or silent awe of those of us privileged to spend time in these waters observing these animals, and the visions that linger just behind our eyelids as we fell into an exhausted sleep. We will see what the next year holds for the SAPPHIRE team and the blue whales and krill of the South Taranaki Bight.

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Toward an enhanced understanding of large whale ecology: a standardized protocol to quantify hormones in whale blubber

Dr. Alejandro A. Fernández Ajó, Postdoctoral Scholar, Marine Mammal Institute – OSU Department of Fisheries, Wildlife, & Conservation Sciences, Geospatial Ecology of Marine Megafauna (GEMM) Lab.

Whales are exposed to an increasing number of human-induced stressors—ranging from pollution and bycatch to the impacts of climate change on prey quality and distribution. Understanding how these factors affect whale health is critical for their conservation. The use of alternative approaches (i.e., alternative to blood samples) for gathering physiological information on large whales using a variety of non-lethal and non to minimally invasive sample matrices (i.e., blubber biopsies, blow, and fecal samples) provides a window into their endocrine state, allowing researchers to assess how these animals respond to both short-term and long-term stressors, and assess their reproductive and nutritional status. However, a lack of standardized protocols might hinder the comparability of results across studies, making it difficult to draw broad conclusions about the health and reproductive parameters of different whale populations.

Dr. Logan Pallin and I organized a lab exchange, funded by The Company of Biologists, to start a new collaboration aimed at bridging this gap by validating and standardizing methods for endocrine assessments in whale blubber. This is not just a technical exercise; it is a foundational step towards building equity and capacity in laboratories worldwide to conduct reliable and comparable endocrine assessments, enhancing the opportunities for multi-lab collaborations. Through this exchange, we aim to consolidate a standardized approach that will yield consistent results between laboratories, enabling better comparisons across different large whale populations. Hosted by the University of California Santa Cruz Biotelemetry and Behavioral Ecology Lab (UCSC-BTBEL Lab) under the mentorship of Dr. Logan Pallin, this experience is instrumental in advancing my research on large whale ecology and conservation.

Dr. Logan Pallin and Alejandro Fernandez Ajó conducting hormone extractions from gray whale blubber samples (left). Preparing a microtiter assay plate for hormone quantification in blubber (right).

During this exchange at the BBE Lab, I had the privilege of working closely with Dr. Logan Pallin, whose expertise in large whale endocrinology (particularly analyzing blubber biopsies) has been instrumental in shaping modern approaches to whale research. The lab’s cutting-edge equipment and Logan’s extensive experience with hormone extraction and quantification methods provided an ideal setting for refining our protocols. Our work focused on the extraction and quantification of progesterone from gray whale blubber samples provided by the Oregon State University Marine Mammal Stranding Network, part of MMI. These large blubber sections allow for repeated sub-sampling to ensure that the selected immunoassays reliably detect and measure the hormones of interest, while also assessing potential sources of variability when applying a standardized protocol. We initially focused our tests and validations on progesterone, as it is the precursor of all major steroid hormones and serves as an indicator of reproductive state in females.

A fieldwork day off Monterrey Bay, California with Dr. Logan Pallin, and PhD candidate Haley Robb. Blubber. Blubber biopsies can be obtained from free swimming whales with minimally invasive methods. From each sample we can derive multiple information about the reproductive status, genetics and overall health of the individuals.

The broader impact of our work
The successful validation and standardization of these protocols represents a significant advancement in whale conservation physiology. Once these methods are established, we plan to acquire funds to apply them to a larger collection of blubber samples. We hope to expand our work to include other species and regions, building a broader network of researchers dedicated to studying large whales in a rapidly changing world, and to assess hormone profiles in relation to factors like reproductive success, body condition, and exposure to stressors such as vessel traffic and environmental changes.

During our fieldwork in Monterey Bay, we had fascinating encounters with Minke whales (Balaenoptera acutorostrata, top left), a large group of Risso’s dolphins (Grampus griseus, bottom left), playful Humpbacks (Megaptera novaeangliae, top right), and a Blue whale (Balaenoptera musculus, no photo).

As I conclude this lab exchange, I am filled with excitement for the future. The knowledge and skills gained during this experience will undoubtedly shape the next phase of my research, allowing me to contribute more effectively to the conservation of these incredible animals. I look forward to applying these standardized methods to ongoing and future projects, and to continuing this fruitful collaboration with the BBE Lab. This journey has reinforced the importance of collaboration, standardization, and innovation in the field of conservation physiology. By working together, we can better understand the complex lives of large whales and take meaningful steps towards their protection in an increasingly challenging environment.

Acknowledgments: This exchange was made possible by the support of The Company of Biologists Traveling Fellowship Grant. I would like to thank Dr. Ari Friedlaender (BBE Lab PI) for facilitating this exchange, and Dr. Leigh Torres (GEMM Lab PI) and Dr. Lisa Balance (MMI director) for their support in helping me expand my collaboration network and skillsets. Special thanks to PhD student Haley Robb for her assistance in the laboratory and fieldwork, and a heartfelt thank you to Dr. Logan Pallin for generously sharing his knowledge and time.

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The Beginning of the End

By Rachel Kaplan, PhD candidate, Oregon State University College of Earth, Ocean, and Atmospheric Sciences and Department of Fisheries, Wildlife, and Conservation Sciences, Geospatial Ecology of Marine Megafauna Lab

I moved to Corvallis exactly four years ago, in the deep, dark midst of the Covid pandemic, and during the added chaos of the 2020 Labor Day Fires, some of the worst in Oregon’s history. I vividly remember attending our virtual lab meeting sitting on the floor surrounded by boxes, while my labmates told me their own stories (many, surprisingly!) of moving during natural disasters. At the time, beginning graduate school represented so many big changes in my life: I had quit my job, sold my furniture, and moved across the country, hoping to explore an area of research that had been calling to me for years, and to gain a new skillset and confidence.

Highlight: A very pandemic cruise. My first day of marine mammal fieldwork in 2021, at sea with (now Dr.) Dawn Barlow.

Now, I’m starting the fifth year of my PhD, thinking about all that has happened and all that is to come. Graduate school is full of milestones to mark time and progress: I’ve taken the courses required for my program, sat for a written exam to test my broad knowledge of oceanography, and written a dissertation proposal. Earlier this year, I spent two months buried in the literature on oceanography, krill, and whale ecology in preparation for my oral qualifying exam. I’ve stared at the water for dozens of hours watching for whales off the Oregon coast, and experienced polar night studying winter krill in Antarctica. I’ve conquered my fear of learning to code, and felt constant, profound gratitude for the amazing people I get to work with.

The last four years have been incredibly busy and active, but now more than ever, it feels like the time to really do. I can see the analytical steps ahead for my final two dissertation chapters more clearly than I’ve been able to see either of the other two chapters that have come before. One of my favorite parts of the process of research is discussing analytical decisions with my labmates and supervisors, and experiencing how their brains work. Much of our work hinges on modeling relationships between animals and their environment. A model, most fundamentally, is a reduced-scale representation of a system. As I’ve learned to use statistical models to understand relationships between krill and whales, I have simultaneously been building a mental model of the Northern California Current (NCC) ecosystem and the ecological relationships within it. Just as I have long admired in my supervisors and labmates, I can now feel my own mind becoming more playful as I think about this ocean environment, the whales and krill that make a living in the NCC, and the best way to approach studying them analytically.

Highlight: Working on my dissertation proposal during a friend’s 2022 wedding celebration in Utah.

Graduate school demands that you learn and work to constantly exceed your own bounds, and pushing to that extent for years is often stressful and even existentially threatening. However, this process is also beautiful. I have spent the last four years growing in the ways that I’ve long wanted to, and reveled in feeling my mind learn to play. I wouldn’t give up a moment of the time I’ve spent in the field, the relationships I’ve built with my labmates, or the confidence I’ve developed along the way.

As I look ahead to this next, final, year of graduate school, I hope to use what I’ve learned every day – and not just about how to conduct research, but about myself. I want to always remember that krill, whales, and the ocean ecosystem are incredible, and that it is a privilege to study them. I hope to work calmly and intentionally, and to continue appreciating this process of research and growth.

Highlight: My first in-person oral presentation, at the 2024 ICES-PICES International Zooplankton Production Symposium in Hobart, Tasmania.

The Theme of the Year is Learning New Things!

By Hali Peterson, rising freshman, Western Oregon University

Hello, my name is Hali Peterson and I am a rising freshman in college. Last summer (2023) I was given the opportunity to be a paid high school intern for the OSU Marine Mammal Institute’s very own GEMM Lab (Geospatial Ecology of Marine Megafauna Laboratory) based at the Hatfield Marine Science Center in Newport, Oregon. My time working in the GEMM Lab has been supported by the Oregon Coast STEM Hub. I started my internship in June 2023 and I was one of the two GEMM Lab summer interns. However, my internship did not end when summer did, as I continued to work throughout the school year and even into this summer. 

Figure 1: Leaving work late and accompanied with a beautiful view of the Newport bridge over Yaquina Bay.

June 29, 2023 to September 20, 2024 (1 year, 2 months, and 21 days if anyone is curious) – what did I do and what did I learn during this time…

Initially, I was tasked with helping the GRANITE project (Gray whale Response to Ambient Noise Informed by Technology and Ecology) by processing drone footage of Pacific Coast Feeding Group (PCFG) gray whales and identifying their zooplankton prey. I started off my internship under the mentorship of KC Bierlich and Lisa Hildebrand and I dove into looking at zooplankton underneath a microscope and watching whales in drone footage, both gathered by the GEMM Lab field team. 

KC taught me how to process drone footage, measure whales and calibration boards, test an artificial intelligence model, as well as write a protocol of the drone processing methods that I had worked on. These tasks were a big responsibility as the measurements need to be accurate and precise so that they can be used to effectively assess the body condition of gray whales, which provides crucial insights into population health.

Figure 2: My favorite drone video of moms and calves meeting up for a playdate!

Under Lisa’s mentorship I learned how to identify and process zooplankton prey samples, process underwater GoPro videos, as well as identify and analyze kelp patches from satellite images. Within these tasks, I honed my expertise in zooplankton and habitat analysis and the results of my work will contribute to a deeper understanding of gray whale feeding habits along the Oregon coast.

Figure 3: My favorite zooplankton to see, a juvenile crab larva.

As my main mentors, KC and Lisa taught me so much about the world of science and research. All of these detail-oriented and multi-layered tasks helped me improve some of the skills I already had before I started the internship as well as gift me with skills I didn’t previously possess. For example, I learned how to collaborate and work with a team, pay attention to detail, double and even triple check everything for quality work, problem solve, and learn to ask questions. 

However, as my time in the GEMM Lab extended beyond the summer of 2023, so did my tasks. Later on I received another mentor, Clara Bird. Under Clara I learned how to identify whales from drone footage recorded in Baja, Mexico (an area that is specifically known as the breeding lagoons where the gray whales go in the winter), as well as use the Newport, Oregon drone footage and CATS (Customized Animal Tracking Solution) tag data to measure inhalation duration and bubble blast occurrences. These experiences furthered my knowledge and yet again I learned something new, a common theme throughout my time in the GEMM Lab. 

Just a few months ago, the GEMM Lab hired Laura Flores Hernandez as a new high school student summer intern, and under the guidance of both Lisa Hildebrand and Leigh Torres, I was given the opportunity to develop my own mentoring skills. I used the skills I had obtained over the past year to teach someone else how to do the tasks I once was new to. I taught Laura how to identify zooplankton, process drone footage, and measure calibration boards. Stepping into that mentor role helped me reflect on my own learning and experiences. I had to go back and figure out how I did things, where I struggled, and how I overcame those struggles. Not an easy task but one I was glad to be presented with. 

Figure 4: Matthew Vaughan (chief scientist on the trip) and me (right) looking at a box core sample.

During my time here I was also invited to join a STEM (Science, Technology, Engineering, Mathematics) cruise led by Oregon Sea Grant with fellow high school students. On this science cruise I got to help look at box core samples (a tool used to collect large amounts of sediment off of the ocean floor). Equipped with my previous knowledge on zooplankton identification, I was able to help the chief scientist on the trip to explain to other high school students what we were seeing in the samples. This trip helped me grow my teamwork and identification skills, as well as experience what it is like to collect data while on a moving ship. 

Figure 5: Sea Kayaking through the fjord with the Girls on Icy Fjords team of 2024.

Another amazing opportunity I was selected for was to join the 2024 Girls on Icy Fjords team. This program, in association with OSU, was designed to empower young women in STEM in the backcountry of Alaska. With a team of 3 amazing instructors and 8 girls (all from different parts of the United States of America) we camped in the backcountry for 8 days, learning about glaciers and fjords, surviving in the backcountry, sea kayaking, and working as a team. I would highly recommend any young woman interested in science, art, or just an amazing experience to check out Inspiring Girls Expeditions.

Bonus Image: This is Jeff the Moyebi Shrimp and I love him.

All in all this will be a job that I will not soon forget; interning in the GEMM Lab has been both a learning opportunity as well as a challenge. My internship wasn’t without its challenges, from a computer that seemed determined to shut down whenever I made progress, to endless hours spent staring at a green screen, waiting to count a fish that might eventually swim by. Though the job had its ups and downs, I am so glad I was given this opportunity and was kept on in the lab for as long as I was. In just a few weeks, I will start my Bachelors of Aquarium Science at Western Oregon University and I’m both excited and nervous. I know that without a doubt the skills I learned during this internship will come in handy as I continue my education and pursue a career in the future. 

Thank you to all my mentors, anyone who answered one of the many questions I had, and to the friends I made along the way!

A Summer of Crustacean Investigation

By Matoska Silva, OSU Department of Integrative Biology, CEOAS REU Program

My name is Matoska Silva, and I just finished my first year at Oregon State University studying biology with a focus in ecology. This summer will be my first experience with marine ecology, and I’m eager to dive right in. I’m super excited for the opportunity to research krill due to the huge impacts these tiny organisms have on their surrounding ecosystems. The two weeks I’ve spent in the CEOAS REU so far have been among the most fun and informative of my life, and I can’t wait to see what else the summer has in store for me.

Figure 1. Matoska presents his proposed research to the CEOAS REU program.

I’ve spent most of my life in Oregon, so I was thrilled to learn that my project would focus on krill distribution along the Oregon Coast that I know and love. More specifically, my project focuses on the Northern California Current (NCC, the current found along the Oregon Coast) and the ways that geographic distribution of krill corresponds to climatic conditions in the region. Here is a synopsis of the project:

The NCC system, which spans the west coast of North America from Cape Mendocino, California to southern British Columbia, is notable for seasonal upwelling, a process that brings cool, nutrient-rich water from the ocean depths to the surface. This process provides nutrients for a complex marine food web containing phytoplankton, zooplankton, fish, birds, and mammals (Checkley & Barth, 2009). Euphausiids, commonly known as krill, are among the most ecologically important zooplankton groups in the NCC, playing a vital role in the flow of nutrients through the food web (Evans et al., 2022). Euphausia pacifica and Thysanoessa spinifera are the predominant krill species in the NCC, with T. spinifera mainly inhabiting coastal waters and E. pacifica inhabiting a wider range offshore (Brinton, 1962). T. spinifera individuals are typically physically larger than E. pacifica and are generally a higher-energy food source for predators (Fisher et al., 2020). 

Temperature has been previously established as a major factor impacting krill abundance and distribution in the NCC (Phillips et al., 2022). Massive, ecosystem-wide changes in the NCC have been linked to extreme warming brought on by the 2014-2016 marine heatwave (Brodeur et al., 2019). Both dominant krill species have been shown to respond negatively to warming events in the NCC, with anomalous warm temperatures in 2014-2016 being linked to severe declines in E. pacifica biomass and with T. spinifera nearly disappearing from the Oregon Coast (Peterson et al., 2017). Changes in normal seasonal size variation and trends toward smaller size distributions in multiple age groups have been observed in E. pacifica in response to warming in northern California coastal waters (Robertson & Bjorkstedt, 2020). 

The El Niño-Southern Oscillation (ENSO) is a worldwide climatic pattern that has been linked to warming events and ecosystem disturbances in the California Current System (McGowan et al., 1998). El Niño events of both strong and weak intensity can result in changes in the NCC ecosystem (Fisher et al., 2015). Alterations in the typical zooplankton community accompanying warm water conditions and a decline in phytoplankton have been recorded in the NCC during weak and strong El Niño occurrences (Fisher et al., 2015). A strong El Niño event occurred in 2023 and 2024, with three-month Oceanic Niño Index means reaching above 1.90 from October 2023 to January 2024 (NOAA Climate Prediction Center, https://www.cpc.ncep.noaa.gov/data/indices/oni.ascii.txt).   

Figure 2. A graph of the ONI showing variability across two decades. Retrieved from NOAA at https://www.climate.gov/news-features/understanding-climate/climate-variability-oceanic-nino-index 

While patterns in krill responses to warming have been described from previous years,  the effects of the 2023-2024 El Niño on the spatial distribution of krill off the Oregon coast have not yet been established. As climate models have predicted that strong El Niño events may become more common due to greenhouse warming effects (Cai et al., 2014), continuing efforts to document zooplankton responses to El Niño conditions are vital for understanding how the NCC ecosystem responds to a changing climate. By investigating krill spatial distributions in April 2023, during a period of neutral ENSO conditions following a year of La Niña conditions, and April 2024, during the 2023-2024 El Niño event, we can assess how recent ENSO activity has impacted krill distributions in the NCC. In addition to broader measures of ENSO, we will examine records of localized sea surface temperatures (SST) and measurements of upwelling activity during April 2023 and 2024.

Understanding spatial distribution of krill aggregations is both ecologically and economically relevant, with implications for both marine conservation and management of commercial fisheries. Modeling patterns in the distribution of krill species and their predators has potential to inform marine management decisions to mitigate human impacts on marine mammals like whales (Rockwood et al., 2020). The data used to identify krill distribution were originally collected as part of the Marine Offshore Species Assessments to Inform Clean Energy (MOSAIC) project. The larger MOSAIC initiative centers around monitoring marine mammals and birds in areas identified for possible future development of offshore wind energy infrastructure. The findings of this study could aid in the conservation of krill consumers during the implementation of wind energy expansion projects. Changes in krill spatial distribution are also important for monitoring species that support commercial fisheries. Temperature has been shown to play a role in the overlap in distribution of NCC krill and Pacific hake (Merluccius productus), a commercially valuable fish species in Oregon waters (Phillips et al., 2023). The findings of my project could supplement existing commercial fish abundance surveys by providing ecological insights into factors driving changes in economically important fisheries.

Figure 3. The study area and transect design of the MOSAIC project, during which active acoustic data was collected (MOSAIC Project, https://mmi.oregonstate.edu/marine-mammals-offshore-wind). 

I’m very grateful for the chance to work on a project with such important implications for the future of our Oregon coast ecosystems. My project has a lot of room for additional investigation of climate variables, with limited time being the main constraint on which processes I can explore. There are also unique methodological challenges to address during the project, and I’m ready to do some experimentation to work out solutions. Wherever my project takes me, I know that I will have developed a diverse range of skills and knowledge of krill by the end of the summer.

References

Brinton, E. (1962). The distribution of Pacific euphausiids. Bulletin of the Scripps Institution of Oceanography, 8(2), 51-270. https://escholarship.org/uc/item/6db5n157 

Brodeur, R. D., Auth, T. D., & Phillips, A. J. (2019). Major shifts in pelagic micronekton and macrozooplankton community structure in an upwelling ecosystem related to an unprecedented marine heatwave. Frontiers in Marine Science, 6. https://doi.org/10.3389/fmars.2019.00212 

Cai, W., Borlace, S., Lengaigne, M., van Rensch, P., Collins, M., Vecchi, G., Timmermann, A., Santoso, A., McPhaden, M. J., Wu, L., England, M. H., Wang, G., Guilyardi, E., & Jin, F. F. (2014). Increasing frequency of extreme El Niño events due to greenhouse warming. Nature Climate Change, 4, 111–116. https://doi.org/10.1038/nclimate2100 

Checkley, D. M., & Barth, J. A. (2009). Patterns and processes in the California Current System. Progress in Oceanography, 83, 49–64. https://doi.org/10.1016/j.pocean.2009.07.028 

Evans, R., Gauthier, S., & Robinson, C. L. K. (2022). Ecological considerations for species distribution modelling of euphausiids in the Northeast Pacific Ocean. Canadian Journal of Fisheries and Aquatic Sciences, 79, 518–532. https://doi.org/10.1139/cjfas-2020-0481 

Fisher, J. L., Peterson, W. T., & Rykaczewski, R. R. (2015). The impact of El Niño events on the pelagic food chain in the northern California Current. Global Change Biology, 21, 4401–4414. https://doi.org/10.1111/gcb.13054 

Fisher, J. L., Menkel, J., Copeman, L., Shaw, C. T., Feinberg, L. R., & Peterson, W. T. (2020). Comparison of condition metrics and lipid content between Euphausia pacifica and Thysanoessa spinifera in the Northern California Current, USA. Progress in Oceanography, 188, 102417. https://doi.org/10.1016/j.pocean.2020.102417

McGowan, J. A., Cayan, D. R., & Dorman, L. M. (1998). Climate-ocean variability and ecosystem response in the Northeast Pacific. Science, 281, 210–217. https://doi.org/10.1126/science.281.5374.210 

Phillips, E. M., Chu, D., Gauthier, S., Parker-Stetter, S. L., Shelton, A. O., & Thomas, R. E. (2022). Spatiotemporal variability of Euphausiids in the California Current Ecosystem: Insights from a recently developed time series. ICES Journal of Marine Science, 79,   1312–1326. https://doi.org/10.1093/icesjms/fsac055 

Phillips, E. M., Malick, M. J., Gauthier, S., Haltuch, M. A., Hunsicker, M. E., Parker‐Stetter, S. L., & Thomas, R. E. (2023). The influence of temperature on Pacific hake co‐occurrence with euphausiids in the California Current Ecosystem. Fisheries Oceanography, 32, 267–279. https://doi.org/10.1111/fog.12628

Peterson, W. T., Fisher, J. L., Strub, P. T., Du, X., Risien, C., Peterson, J., & Shaw, C. T. (2017). The pelagic ecosystem in the Northern California Current off Oregon during the 2014–2016 warm anomalies within the context of the past 20 years. Journal of Geophysical Research: Oceans, 122(9), 7267–7290. https://doi.org/10.1002/2017jc012952 

Robertson, R. R., & Bjorkstedt, E. P. (2020). Climate-driven variability in Euphausia pacificasize distributions off Northern California. Progress in Oceanography, 188, 102412.https://doi.org/10.1016/j.pocean.2020.102412