Deaths of Thousands of Seabirds in the Bering Sea Also Linked To Climate Change By Scientists
The carcasses of tufted puffins were discovered one by one on the shores of a tiny Alaskan outpost in the southern Bering Sea known as St. Paul Island, for months beginning in October 2016.
“It was very apparent that something strange was happening. They just keep washing in and washing in,” said Lauren Divine, director of the Aleut Community of St. Paul Island Ecosystem Conservation Office, who helped oversee the birds’ collection. “Every person in our community knew something was wrong.”
Tufted puffins are the odd-looking seabirds having rounded heads along with golden head plumes and distinctive bright orange bills. These migrate south to warmer waters late in the year that any puffins wash ashore was hardly found. However, along with hundreds of emaciated puffin carcasses, there were also dead bodies of crested auklet, a second species found, it alarmed and surprised the scientists and residents.
“Part of the mystery is what in the heck were those guys doing there? Why hadn’t they left? … That means there’s something going on in the system that’s not too good,” said Julia Parrish, a professor at the University of Washington who also runs the Coastal Observation and Seabird Survey Team, or COASST, a large citizen-science project. “We know month in and month out what is normal, what to expect.”
The widespread decline in the number of these widely beloved birds off coastal Alaska is the evidence of a growing number of “mass mortality events” in recent times affecting seabirds. It was anything but normal.
Parrish and a group of colleagues estimated based on weather data, the possible death of birds between 3,150 and 8,500, most likely from starvation. As the paper published in the journal PLOS One on Wednesday disclosed, the die-off is at least partially attributable to the climate change according to the author.
“This mortality event represents one of multiple seabird mortality events that have occurred in the Northeast Pacific from 2014 to 2018, cumulatively suggestive of broad-scale ecosystem change,” they write. Such episodes, they add, “are indicators of a changing world, and particularly of climate warming.”
Tufted puffins usually breed in the Bering Sea off the Alaskan coast, and feed on various fish, and marine invertebrates, those themselves depend on plankton for their food. Puffins and other birds depend on certain “forage fish” to survive such as capelin, juvenile pollock, and other energy-rich prey but they have migrated due to several years of significant warming and reduction in sea ice.
The authors suggest the climate-fueled shifts were probably affecting the food supply and ultimately destined the puffins that washed ashore on the Island of St. Paul. Additionally, the birds were also in molt, a process that not only replaces their feathers but also impedes their flying ability.
“They didn’t get where they were going,” Parrish said. “They ran out of gas. They ran out of time.”
Between 2015 and into early 2016 similar circumstances occurred off Alaska and other parts of the U.S. Pacific Coast also caused an unprecedented die-off of common murres-a thin-billed sea bird. The following year, another seabird die-off affecting northern fulmars-short-tailed shearwaters, and other species occurred in Alaska’s Bering Sea and Chukchi sea of Russia.
According to the National Park Service, 2018 marked as the third year in a row that scientists documented “massive” seabird die-offs in the region of Bering Sea. In the North Pacific, it was the fifth consecutive season of mass mortality events and in Alaska the fourth straight year of these die-offs, Parrish said.
“Seabirds are good indicators of ocean ecosystem health. Recent mortality events are concerning in that they may be pointing to significant changes in marine ecosystems,” the agency wrote in an update late last year.
In California, the dead and dying common murres have been reported along the Mendocino County coastline recently this month, though the cause of that die-off was not determined yet.
“We are now just bracing for what is going to wash in next,” Divine said. “It’s kind of terrifying.”
In recent years these kind episodes have also unfolded also in other locations in the world.
The puffins have been found dying of starvation and losing body weight in the Gulf of Maine. However, to boost the populations, scientists there have helped aid breeding. As per the scientists, partially the human factors such as hunting along with changes to food supplies are the reasons behind the decline in the populations of puffin across the Atlantic.
Wednesday’s study followed a United Nations report beginning of this month disclosing that roughly plant and animal species about a million are on the verge of extinction, and the implications are alarming for the survival of the human. That report led by seven co-authors from universities worldwide goes further than previous studies by linking the loss of species to human activity directly. The report also detailed how those losses are undermining human health.
What actually caused the puffin die-off, precisely in 2016, along with others documented before remains a question as of now, acknowledged Parrish.
“People often think you can point to climate change the way you can point to a person with a gun who had just shot somebody,” she said.
The reality isn’t straightforward when it comes to finding out all the forces shaping the Bering Sea like a complex ecosystem, she said. However, according to her, each die-off gives clues that significant changes are underway, and there may be more troubling patterns in the future.
“Each one of those is like a bell going off,” she said. “And there’s been a lot of ringing lately.”