Thin, battered gray whales have been turning up dead on Oregon beaches since late 2025, and the strandings have not stopped. At least several carcasses found along the central and southern coast this spring showed the hallmarks of severe malnutrition: sunken flanks, visible shoulder blades, and blubber so depleted that ribs pressed through the skin. Stranding responders with the West Coast Marine Mammal Stranding Network collected tissue samples and measurements, but formal necropsy results have not yet been released through NOAA’s official channels.
The deaths arrive at an uncomfortable moment. The eastern North Pacific gray whale population is still climbing back from a mass die-off between 2019 and 2023 that NOAA classified as an Unusual Mortality Event, or UME. During those five years, more than 600 gray whales stranded along the west coasts of the United States, Canada, and Mexico. Many were emaciated. The agency closed its UME investigation in 2024, concluding that starvation linked to poor Arctic feeding conditions was the primary driver, though ship strikes and entanglement also contributed.
Now, with fresh carcasses on Oregon sand, marine biologists are watching closely to see whether the pattern is repeating.
A population still below its peak
NOAA’s Southwest Fisheries Science Center conducts shore-based surveys each winter to estimate how many gray whales pass south along the migration corridor. The most recent technical memorandum covering the 2024/2025 survey season puts the eastern North Pacific population in the range of roughly 14,500 to 17,000 animals, depending on the statistical model and confidence interval used. That figure represents a meaningful rebound from the UME-era low of around 14,000 estimated in 2023, but it remains well below the most recent peak of approximately 27,000 whales recorded in 2016.
The gap matters because gray whales were once considered a conservation success story. Hunted nearly to extinction by commercial whaling, the eastern population recovered enough to be removed from the Endangered Species List in 1994. For two decades it hovered near what some scientists believed was the habitat’s carrying capacity. Then the bottom fell out.
Between 2016 and 2023, the population lost roughly a third of its numbers. The UME was the most visible symptom, but the decline had likely begun before the first wave of strandings made headlines. Researchers suspect that shifting conditions in the Bering and Chukchi seas, where gray whales gorge on amphipods and other benthic invertebrates during summer, reduced the food supply enough to push a large segment of the population into nutritional deficit.
Calf counts signal ongoing stress
One of the clearest biological stress indicators for gray whales is calf production. When females cannot store enough energy on the feeding grounds, they may abort pregnancies, produce smaller calves, or skip breeding entirely. NOAA’s calf surveys, conducted from counting stations along the central California coast during the southbound migration, have tracked this metric for years.
Calf numbers crashed during the UME, dropping to fewer than 100 observed in some seasons. Production ticked upward in the 2023/2024 season, but NOAA has noted that output remains below the levels biologists would expect from a population in healthy recovery. Low calf counts do not just reflect current hardship; they forecast future population limits, because fewer calves today means fewer breeding adults a decade from now.
For the whales that migrate along the Oregon coast, the stakes are compounded by the existence of the Pacific Coast Feeding Group, or PCFG, a smaller subset of roughly 200 to 300 gray whales that break off from the main migration and spend the summer feeding in nearshore waters from northern California to British Columbia rather than continuing to the Arctic. PCFG whales are genetically connected to the larger population but behaviorally distinct, and their smaller numbers make them more vulnerable to localized threats such as prey depletion, vessel traffic, and entanglement in crab pot lines. Whether any of the recent Oregon strandings involved PCFG animals is not yet known.
What necropsies can and cannot tell us
A peer-reviewed study published in PLOS ONE examined post-mortem findings from gray whales collected between December 2018 and 2021, covering the deadliest stretch of the UME. The pathology work established clinical benchmarks for what starvation looks like in Eschrichtius robustus: blubber thickness reduced to a few centimeters, skeletal muscle wasting, depleted fat reserves around internal organs. The study also screened for disease, biotoxins, and trauma, finding that while some whales had been struck by ships or tangled in gear, the dominant pattern was nutritional depletion.
Those benchmarks are now the reference standard for evaluating new strandings. Field responders on Oregon beaches can make preliminary assessments of body condition, but a definitive cause of death requires laboratory work: histopathology of organ tissue, toxicology panels, and sometimes genetic sampling to determine whether a whale belonged to the PCFG or the main migratory stock. The West Coast Marine Mammal Stranding Network coordinates that process, and results can take weeks or months to finalize.
As of spring 2026, NOAA has not declared a new Unusual Mortality Event. That designation is not triggered by a single number of strandings; it requires evidence of elevated mortality above historical baselines, indications of a common cause, and concern that the event is ongoing. The absence of a declaration does not mean the strandings are insignificant. It means the data have not yet crossed the formal threshold, and federal scientists are still collecting and analyzing information.
Arctic feeding grounds under pressure
The thread connecting emaciated whales on Oregon beaches to conditions thousands of miles north runs through the Arctic food web. Gray whales are among the few large whale species that feed primarily on the seafloor, using baleen plates to filter amphipods, mysid shrimp, and other small invertebrates from bottom sediments. The richest feeding areas sit in the Bering and Chukchi seas, where cold, nutrient-dense water supports dense mats of benthic prey.
Over the past decade, those waters have warmed significantly. Sea ice has retreated earlier in spring and formed later in fall, altering the timing and distribution of the algal blooms that fuel the benthic food chain. NOAA and academic researchers have documented broad shifts in Arctic marine ecosystems, including changes in species composition and productivity on the seafloor. What has been harder to pin down is the precise impact on amphipod biomass in the specific areas where gray whales feed, because benthic surveys are expensive, logistically difficult, and not conducted every year.
The result is a plausible but incompletely quantified link: Arctic conditions are changing in ways that could reduce gray whale prey, and whales are arriving on the migration route in poor condition. Filling in the gap between those two observations requires more granular data on prey availability during the 2025 feeding season, data that have not yet been published.
What happens next on Oregon beaches
For coastal communities, the immediate reality is practical. A dead gray whale on a public beach is a 30- to 40-ton problem that involves public health concerns, access restrictions, and difficult logistics. Local authorities and stranding network volunteers must decide whether to conduct a full necropsy on site, tow the carcass offshore, or let it decompose naturally. Each choice carries trade-offs in cost, data quality, and community impact.
Anyone who encounters a stranded or distressed whale along the Oregon coast should contact the West Coast Marine Mammal Stranding Network through local authorities or the NOAA Fisheries hotline rather than approaching the animal. Carcasses can harbor bacteria and parasites, and live-stranded whales can injure bystanders with sudden movements of their tails or flippers. Responders trained in marine mammal protocols can secure the scene, collect samples, and feed data back into the same federal tracking systems that documented the 2019 to 2023 UME.
Over the coming months, the necropsy results from this spring’s strandings will begin to clarify whether these deaths fit the starvation pattern of the previous die-off or point to something else entirely. Population surveys during the 2025/2026 migration season will update the abundance estimate. And calf counts will offer another measure of whether the species is gaining ground or losing it.
None of those answers will arrive quickly. Gray whale science operates on the rhythm of annual migrations, seasonal feeding cycles, and laboratory timelines that do not bend to news cycles. What is already clear is that the population has not returned to its former strength, that the ocean conditions shaping its future are still in flux, and that each emaciated carcass on an Oregon beach is a data point in a story that is far from over.
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*This article was researched with the help of AI, with human editors creating the final content.
