Puffins are dying in worryingly large numbers in Alaska and scientists say it could be directly linked to climate change.
According to a new study published in PLOS ONE, there's been a mass die-off of tufted puffins and crested auklets on St. Paul Island, one of the Pribilof Islands in the Bering Sea, off the coast of Alaska.
Between Oct. 2016 and Jan. 2017, over 350 bird carcasses were recovered by tribal and community members, many washed up on beaches, the study reports. Tufted puffins made up 87 percent of the total, when in previous years, they only made up one percent of recovered birds.
The puffins were mostly adult birds, suffering from the onset of molt — a regular, rather stressful shedding and regrowth of feathers that increases the birds' nutritional needs during the process.
But how did they die? Starvation.
Image: De Agostini/Getty Images
It's the puffins' death from a lack of food that's truly concerned the study's authors, a team helmed by Timothy Jones, a researcher with the University of Washington's citizen science project, COASST.
The authors observed that the tufted puffins of the Bering Sea feed on fish and other marine invertebrates, which, in turn, feed on plankton. But the puffins' prey is becoming less abundant.
Where did the puffins' food go?
Rising sea temperatures caused by global warming have caused marine ecosystems and food webs to go through significant changes, with some species reducing in abundance, including fish like pollock and crustaceans like krill on the southern Bering Sea shelf. And who eats pollock and krill? Tufted puffins and crested auklets, respectively.
These changes within marine ecosystems have already lead to mass mortality events (MMEs) in seabirds — the study notes two for the north Pacific due to ecosystem shifts between 2013 and 2017. In fact, they're becoming so frequent that they're one of the most important indicators of the effects of accelerated climate change.
"Large-scale shifts in climate have been punctuated by large mortality events of marine birds," the study reads. "As abundant, visible, upper-trophic organisms, seabirds have been proposed as indicators of marine ecosystem shifts due to climate, with documented effects of climate variability on both reproduction and adult survival."
The Bering Sea sits at high latitude between the north Pacific and Arctic Oceans. The Arctic is the most rapidly changing region on Earth, and the Bering Sea embodies these drastic changes. In March, the Bering Sea was nearly ice-free, months ahead of schedule. It was the lowest extent in the 40-year satellite record. Atmospheric conditions from 2014 onwards, the study notes, have caused less winter sea ice and higher water temperatures.
In fact, temperatures in northern Alaska are rising faster than anywhere else in the U.S. And that's incredibly bad news for the tufted puffin population.
The power of citizen science
Aside from being a wake-up call to the devastating, real effects of climate change on our natural world, the study is a testament to the power of community observation in dramatically affected areas.
"This paper is a successful application of citizen science in the real world," said co-author Lauren Divine from the Aleut Community of St Paul Island Ecosystem Conservation Office, who noted the role island residents played in collecting the birds and providing data for COASST.
"Without the positive and mutually beneficial relationship built over years of collaboration, this massive die-off of tufted puffins would have gone unreported in the scientific community."