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Ocean Heat Wiped Out Half These Seabirds Around Alaska

海洋热浪
鸟类死亡
生态系统变化
The first ‎ was the feathered bodies ‎ Alaskan ‎. They were ‎ murres, sleek black-and-white seabirds that typically spend months at a time away from land. But in 2015 and 2016, ‎ ‎ 62,000 emaciated corpses from ‎ to Alaska.
Since then, scientists have been ‎ what happened to the birds, along with other ‎ in the northeast Pacific that suddenly died or ‎. It ‎ ‎ that the ‎ was a ‎-breaking ‎ ‎ ‎, a mass of warm water that would come to be known as the Blob. New findings on its ‎ on murres, published on Thursday in the ‎ Science, are a ‎ ‎ of the ‎ ‎ ‎ in a warming world.
About ‎ of Alaska’s ‎ murres, some four ‎ birds, died as a ‎ of the marine ‎ ‎, the scientists ‎. They believe it is the largest ‎ die-off of a ‎ ‎ of ‎ birds or mammals. The state is home to about a quarter of the world’s ‎ murres, scientists say.
Murres were the ‎ of a domino ‎ of oceanic changes ‎ to the warm water, according to a growing body of ‎. It ‎ marine life from plankton to humpback whales. Critically for the murres, it ‎ to a ‎ in the fish they ‎ on.
One of the most ‎ ‎ in the new study is that the birds have not ‎ begun to ‎.
“If the ‎ ‎ are good, I think there’s hope,” Ms. Renner said. “Our ‎ is that events like this are ‎ to ‎ much more ‎, and we haven’t seen any ‎ of ‎ at all yet, eight years after the event.”
For decades, the world’s ‎ have ‎ more than 90 ‎ of the excess ‎ ‎ as humans ‎ ‎ fuels and ‎ ecosystems like ‎. That ‎ has ‎ coral reefs, kelp ‎ and other marine ecosystems. Last year and into this year, the ‎’s ‎ temperature ‎ ‎.
For the murres, earlier ‎ estimates from the Blob were ‎. In 2020, a team of some of the same scientists estimated that ‎ a ‎ to a ‎ of the birds had died in Alaska. But the new ‎ ‎ a different and far more reliable ‎, ‎ earlier data to ‎ before and after counts at 13 ‎ colonies throughout the Gulf of Alaska and the Eastern Bering Sea. The ‎ then ‎ those ‎ across the ‎ ‎.
“We saw exactly the same really ‎ signal at every ‎ colony,” Ms. Renner said. “It wasn’t some of them, it was all of them.”
Avian flu has had huge ‎ on some bird ‎ ‎ the world, but ‎ have not seen much ‎ in Alaska, Ms. Renner said, so it does not appear to be ‎ a ‎ role.
, while ‎ ‎ were ‎ by the Pacific marine ‎ ‎, ‎ some fisheries ‎, not all showed ‎. That ‎ the ‎ changes ‎ “pinch points” in the food ‎ rather than, say, ‎ all ‎.
Mark Mallory, a seabird biologist and professor at Acadia University in Nova Scotia who was not ‎ with the study, said the ‎ ‎ the ‎ ‎ of ‎-term ‎ data in allowing scientists to ‎ the ‎ changes ‎ on Earth.
The finding that murres, ‎ a ‎ ‎, are not regaining their numbers, ‎ him of what happened when people overfished ‎ cod ‎ off Newfoundland, which had once been ‎ ‎ ‎.
“Here we are decades after that ‎ event, and that marine ecosystem has not ‎,” Dr. Mallory said. “It’s ‎ ‎ to me that we are witnessing the early ‎ of a ‎ ‎, ‎ by a different catastrophe, in these Alaskan waters.”
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Ocean Heat Wiped Out Half These Seabirds Around Alaska | Leximory