Dynamic and changing Arctic Ocean conditions likely caused three major mortality events in the eastern North Pacific gray whale population since the 1980s, a new study has found.
During each of these die-offs, including one that began in 2019 and is ongoing, the gray whale population was reduced by up to 25% over just a few years, said Joshua Stewart, an assistant professor with Oregon State University’s Marine Mammal Institute and the study’s lead author.
“These are extreme population swings that we did not expect to see in a large, long-lived species like gray whales,” Stewart said. “When the availability of their prey in the Arctic is low, and the whales cannot reach their feeding areas because of sea ice, the gray whales“>gray whale population experiences rapid and major shocks.”
“Even highly mobile, long-lived species such as gray whales are sensitive to climate change impacts. When there are sudden declines in the quality of prey, the population of gray whales is significantly affected.”
The findings were published in the journal Science.
2023-10-12 13:48:03
Source from phys.org