(CN) – For the past several years, a walk along Alaska shores has brought views of dead or dying seabirds juxtaposed with the raw beauty of rocky sea cliffs or snowcapped mountains – more victims to a changing climate according to a study published Wednesday.
Tuffted puffins are the focus of the study led by Timothy Jones of the citizen science program COASST at University of Washington in coordination with Lauren Divine of the St. Paul Island Ecosystem Conservation Office, located in the Aleut Community in the Pribolof Islands in the southern Bering Sea.
The medium-sized seabirds known for their thick red-orange bills and yellow tufts appear to have died of starvation. They washed ashore in yet another massive die-off of seabirds that has also included species of murres, auklets, petrels, shearwaters and kittiwakes and others along many Alaska coastlines in the last five years.
Scientists say major changes in ocean ecosystems as sea temperatures continue to rise are linked to previous mass mortality events in marine birds.
Tufted puffins breed in the Bering Sea and feed on fish and marine invertebrates, which in turn feed on ocean plankton. Beginning in 2014, increased atmospheric temperatures and decreased winter sea ice led to declines in energy-rich prey species in the Bering Sea, as well as a shift of some species more northward, diminishing the puffins’ food resources in the southern portion of the sea.
Jones and colleagues documented a four-month-long die-off of puffins and a second species, the crested auklet, on St. Paul Island about 300 miles east of mainland Alaska. Beginning in October 2016, tribal and community members recovered more than 350 severely emaciated carcasses. Most were adults in the process of molting, a known nutritional stressor during the avian life cycle.
The authors believe a climate-driven reduction in food resources before entering molt may have prevented many birds from surviving. Using wind data to model beachings, they estimated that between 3,150 and 8,500 birds may have died in the event. Tufted puffins comprised 87% of this total, or 40-100% of the Pribilofs Islands’ population, making it highly likely that affected birds originated from colonies throughout the Bering Sea. In prior years puffins have made up less than 1% of recovered carcasses in the region.
“This paper is a successful application of citizen science in the real world,” Divine, of the St. Paul Island Ecosystem Conservation Office, said in a statement. “Island residents collected high quality data in real time and provided COASST with a detailed context for their analysis. 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.”
Given climate trends, scientists predict further climate variability in the region that will likely continue affecting distribution and abundance of food sources. Scientists say further research and observation will show whether seabirds can remain resilient in an increasingly variable environment.
The scientists published their findings in the open-access journal PLOS ONE.