Tom Perkins “Pacific gray whales facing ‘catastrophic’ die-off as climate crisis hits food supply” https://www.theguardian.com/environment/2026/jul/10/pacific-gray-whales-population-climate-change
気候変動によって、コククジラ（gray whale）*1の個体数の激減が導かれるだろうと、環境団体Public Employees for Environmental Responsibility (Peer) *2が警告している*3。
正確な個体数を割り出すことの困難；
Meanwhile, a range of other issues, like ship strikes, oil spills, microplastic pollution, algal blooms and Russian harvesting are also probably contributing to the die-off that has nearly halved the whales’ estimated population. It fell from 20,000 in 2019 to fewer than 13,000 this year, and the deaths appear to be accelerating.Environmental groups have petitioned the National Oceanic and Atmospheric Administration (Noaa) to relist the gray whale under the Endangered Species Act (ESA), which would alleviate some problems, but its approval is a long shot as the Trump administration moves to gut wildlife protections*4.
The whales are in “very, very serious trouble”, said Rick Steiner, an Alaska marine ecologist and chair of Public Employees for Environmental Responsibility’s (Peer’s) board of directors.“The stranding numbers last year and this year are enormous compared to their annual average,” Steiner said. “Stranding” is the term for whales that wash up onshore.
The gray whales, which travel from Baja California to Alaska to feed each year, came close to extinction in the 1970s, but rebounded following robust conservation efforts. They were delisted from the ESA in 1994, which Steiner called a “colossal mistake”.
The estimates are most dire for 2025 and 2026 – somewhere from 2,500 to 8,000 whales are estimated to have died in this timeframe, which meets the criteria for a “catastrophic mortality event”.
Determining an exact number is difficult because marine biologists can only count the whales that are stranded. The average annual number of gray whale strandings from 2006 to 2023 was 43, but rose to 179 in 2025. Through the first half of this year, 146 whale carcasses have been directly counted*5.
Scientific literature estimates the ratio between unobserved, or sunk, mortalities offshore and observed mortalities onshore for gray whales is between 7-to-1 and 25-to-1*6.
The whales that wash up are emaciated, Steiner said, and the scientific consensus is that they are starving due to a loss of access to food sources that is driven by the dramatic reduction in sea ice around Alaska due to climate change.
While the whales have been resilient in the past, evidence points to a dire situation, said David Weller, a Noaa marine biologist, in an agency release.
“The environment may now be changing at a pace or in ways that is testing the time-honored ability of the population to rapidly rebound while it adjusts to a new ecological regime,” Weller said.
California has ship speed reduction zones in areas known to have higher gray whale concentrations, and, though the program is voluntary, many ships do reduce their speed, and some station spotters to look out for whales, Steiner said. Those have reduced whale ship strike deaths in the region by about 50%.Oregon, Washington and Alaska have not implemented similar programs because of shipping industry opposition, Steiner said, but advocates are pushing for action.
*1:See eg. https://en.wikipedia.org/wiki/Gray_whale https://ja.wikipedia.org/wiki/%E3%82%B3%E3%82%AF%E3%82%AF%E3%82%B8%E3%83%A9
*3:“Gray Whales Suffering “Catastrophic Mortality Event”” https://peer.org/gray-whales-suffering-catastrophic-mortality-event/
*4:See Tom Perkins "Trump orders likely to drive species’ extinction, wildlife advocates warn" https://www.theguardian.com/us-news/2025/mar/11/trump-wildlife-agencies-species-extinction
*5:“West Coast Gray Whale Strandings as of 7-6-26” https://peer.org/wp-content/uploads/2026/07/West-Coast-Gray-Whale-Strandings-as-of-7-6-26.pdf
*6:See Andre E. Punt and Paul R. Wade "Population status of the eastern North Pacific stock of gray whales in 2009" https://peer.org/wp-content/uploads/2026/07/2026_7_6-Punt-and-Wade_2012.pdf
