A tufted puffin (Fratercula cirrhata) on the seacliff of St Paul Island Enrique R. Aguirre Aves/Alamy

Hundreds of “severely emaciated” puffin carcasses have washed ashore on an Alaskan island, and researchers believe thousands more have died at sea as warming waters continue to shrink their food supply.

Between October 2016 and January 2017, inhabitants of St Paul Island in the Bering sea found the starved bodies of more than 350 seabirds, primarily tufted puffins.

Analysing the location of bird carcasses and wind data, Timothy Jones at the University of Washington in Seattle and his colleagues estimated that between 3000 and 9000 birds died in total.


When they examined some of the bodies, they found no signs of infection or unsafe levels of toxins.

“Collected specimens were severely emaciated, suggesting starvation as the ultimate cause of mortality,” Jones wrote.

Tufted puffins, which accounted for 79 per cent of the bird carcasses found, eat fish and marine invertebrates, which in turn eat phytoplankton.

But changes to atmospheric conditions, including the ongoing heatwave, have massively disrupted the marine ecosystems, he wrote. There is less winter sea-ice, and warmer temperatures have been linked to fewer forage fish, crustaceans and other prey animals as they either die off or move north to cooler waters.

Almost all the puffins they found were adults in the process of moulting, which makes them flightless for up to 40 days and requires more nutritional energy than normal.

This combination of factors likely led to the huge numbers of deaths, Jones wrote.

Dead puffins found on St Paul Island in October 2016 Aleut Community of St Paul Island Ecosystem Conservation Office

These mass deaths are increasing in frequency and magnitude, and two other largescale seabird die-offs in the region have been directly linked to a marine heatwave starting in 2013, Jones wrote.

“Whether seabirds are resilient to these changes will ultimately govern their long-term viability in an increasingly variable climate,” he added.

The deaths could affect tufted puffin populations long-term. It’s unclear which colony or colonies the birds came from, but dramatic population declines in the Gulf of Alaska, British Columbia and in the northern California Current make these deaths concerning, Jones wrote.

Journal reference: PLoS One, DOI: 10.1371/journal.pone.0216532