Gray whales have a split story: one population recovered enough to be removed from the U.S. endangered species list in 1994, while the other remains federally listed as endangered. The eastern North Pacific population, which migrates along the west coast of North America, is the larger and more familiar group. The western North Pacific population, found off the coast of Asia, numbers only around 220 to 270 adults and is still considered at serious risk. Even the “recovered” eastern population, however, is in trouble right now, with recent counts showing a steep decline that has scientists concerned.
Two Populations, Two Statuses
Gray whales in the North Pacific exist as two distinct groups. The eastern population breeds in the warm lagoons of Baja California and feeds in Arctic waters during summer, traveling 10,000 to 12,000 miles round trip each year. The western population feeds off Sakhalin Island near Russia, and its wintering grounds remain poorly understood.
The eastern population was listed as endangered under the U.S. Endangered Species Act but was officially delisted in 1994 after rebounding to near its estimated original population size. At the time, federal scientists concluded it was no longer in danger of extinction. The western population never recovered and remains listed as endangered under the ESA and as depleted under the Marine Mammal Protection Act. Photo-identification surveys from 2020 counted roughly 220 to 270 whales (not including calves) feeding off Sakhalin, more than double the count from the early 2000s but still dangerously low for a whale population.
The Eastern Population Is Declining Again
The delisting in 1994 looked like a conservation success story for decades. By 2016, NOAA estimated the eastern population at nearly 27,000 whales, one of the highest counts since surveys began in the late 1960s. Then things went wrong.
An Unusual Mortality Event (UME) began in 2019, with strandings jumping roughly tenfold above normal. NOAA attributed the die-off to ecosystem changes in the Subarctic and Arctic feeding grounds that left whales malnourished, lowered birth rates, and increased deaths. By the winter 2022/2023 survey, the population had dropped to roughly 13,230 to 15,960 whales, comparable to the numbers seen when counting first began in the late 1960s.
The UME officially ended in late 2023, and an initial estimate suggested a possible rebound. That hope didn’t last. The most recent count, from winter 2024/2025, estimated only 11,700 to 14,450 whales, the third lowest number in the entire survey history. Rather than recovering, the population continues to shrink.
Calf Production Has Hit Record Lows
Researchers have counted gray whale mother-calf pairs from a lighthouse near San Simeon, California, since 1994. Calf production has been low every year since the UME began in 2019, a sign that the population isn’t producing enough young to replace the whales it’s losing. The 2025 estimate of just 85 calves is the lowest on record for the entire time series. Without a rebound in births, the population has no mechanism to recover, even if adult survival improves.
Why Arctic Warming Matters to Gray Whales
Gray whales are bottom feeders. They spend about four months each summer in the Bering and Chukchi seas, scooping up tiny crustaceans called amphipods from the seafloor. These amphipods are the caloric foundation that sustains whales through their long migration and breeding season, when they eat little or nothing.
Warming ocean temperatures and disappearing sea ice are reshaping that food web. The loss of sea ice allows more solar heat to reach the water, raising bottom temperatures. Research published in PLOS ONE found that the dominant amphipod species in gray whale feeding areas are physiologically sensitive to warming and may be outcompeted by other organisms better suited to warmer water. The amphipods’ range appears to be shifting northward as conditions change. For gray whales, this means their traditional feeding grounds may no longer hold enough prey to sustain them, forcing longer travel to find food or simply leaving them underfed heading into winter. The extreme ocean heat events in the North Pacific from 2014 to 2016, followed by record-low sea ice in 2017 to 2019, set the stage for the mass die-off that began in 2019.
Ship Strikes and Fishing Gear
Climate-driven food shortages are the biggest current threat, but gray whales also face direct harm from human activity in the ocean. A century-long review of gray whale injuries and deaths from human causes in the North Pacific found that the leading sources were entanglement in unidentified fishing gear (33% of cases), net fisheries (29%), vessel strikes (20%), and pot or trap fisheries (15%). The pattern has shifted over time. Net entanglement dominated through the 1990s. From 2020 onward, vessel strikes and entanglement in pot gear have become the most common causes, likely reflecting changes in fishing practices and increased ship traffic along the coast.
Could the Eastern Population Be Relisted?
The eastern gray whale is not currently classified as endangered or threatened under U.S. law, but the ongoing decline raises real questions about its future. The population has lost more than half its numbers since 2016, calf production is at an all-time low, and the Arctic ecosystem changes driving the decline show no signs of reversing. NOAA scientists have noted that low reproduction since 2019 means the population lacks the capacity to rebound even now that the mortality event has ended. Whether these trends trigger a formal review of the population’s legal status will depend on how the next several survey seasons look, but the trajectory is heading in the wrong direction.