Dying and dead seabirds on Alaska coast expose growing threats of climate change: "The food chain is changing rapidly"
Dead and dying seabirds collected on the coasts of the northern Bering and southern Chukchi seas over the past six years reveal how the Arctic's fast-changing climate is threatening the ecosystems and people who live there, according to a report released Tuesday by U.S. scientists.
Local communities have reported numerous emaciated bodies of seabirds — including shearwaters, auklets and murres — that usually eat plankton, krill or fish, but appear to have had difficulty finding sufficient food. The hundreds of distressed and dead birds are only a fraction of ones that starved, scientists say.
"Since 2017, we've had multi-species seabird die-offs in the Bering Strait region," said Gay Sheffield, a biologist at University of Alaska Fairbanks, who is based in Nome, Alaska, and a co-author of the report. "The one commonality is emaciation, or starvation."
The seabirds are struggling because of climate-linked ecosystem shifts — which can affect the supply and the timing of available food — as well as a harmful algal bloom and a viral outbreak in the region, she said.
And their peril jeopardizes the human communities, as well: "Birds are essential to our region — they are nutritionally and economically essential," said Sheffield.
The data on seabirds is part of an annual report released by the National Oceanic and Atmospheric Administration, called the "Arctic Report Card," that documents changes in a region warming faster than anywhere else on Earth.
"With climate change, the food chain is changing rapidly," said Don Lyons, a conservation scientist at the National Audubon Society's Seabird Institute, who was not involved in the report. "Food isn't predictable in the way it used to be, in terms of where the food is, at different times of the year."
While seabirds naturally experience some lean years, the report documents a worrying pattern, said Lyons. "It seems like we've passed a tipping point — we've moved into a new regime where events that we used to think of as rare and unusual are now common and frequent," the scientist explained.
In the past year, Arctic annual surface air temperatures were the sixth warmest since records began in 1900, the report found, with the last six years collectively accounting for the warmest documented period in history. And satellite records revealed that, for several weeks last summer, large regions near the North Pole were virtually clear of sea ice.
Authors of the latest Arctic Report Card highlighted the ongoing pattern of dying seabirds, which, per the report, correlates to warming temperatures seen over the last six years. Summarizing the report's findings, they noted that, "communities in the northern Bering and southern Chukchi Sea region reported higher-than-expected seabird die-offs for the sixth consecutive year. Tracking the duration, geographic extent, and magnitude of seabird bird die-offs across Alaska's expansive and remote coastline is only possible through well-coordinated communication and a dedicated network of Tribal, State, and Federal partners.
As environmental scientists have pointed out before, the new annual report showed that the Arctic continued to warm at a pace more than twice as fast as the rest of the globe, with more dramatic changes observed in certain locations and during different times of the year. Lower-than-average sea ice recorded this year was similar to the amount observed in 2021, according to the report, and sea surface temperatures collected across most ice-free regions of the Arctic Ocean followed an ongoing upward trend in temperatures.
"The sea ice extent was much lower than long-term average," said Walt Meier, a sea ice expert at the University of Colorado Boulder and a co-author of the report.
"The most notable thing we saw was during the summer, we saw a lot of open-water areas up near the North Pole, which was once very rare," he said. "Several kilometers with very little or no ice, within a couple hundred kilometers of the North Pole."
"The changes that are happening in the Arctic are so fast and so profound," said Peter Marra, a conservation biologist at Georgetown University, who was not involved in the report.
Seabirds are metaphorical canaries in the coal mines, when it comes to showing broader ecosystem changes, Marra said, adding, "We need to do a much better job of monitoring these sentinel populations."