A biologist in Alaska recently came upon a mass seabird die-off on the shores of Prince William Sound near the town of Whittier, in the southern part of the state about 60 miles from Anchorage.

The birds in question were common murres, white ocean flyers that are among North America's most abundant seabirds. They were emaciated and had apparently starved to death, then washed ashore. There were so many that the biologist, David Irons, at first took them for patches of snow.

"It was pretty horrifying," Irons said in an Associated Press article. "The live ones standing along the dead ones were even worse."

While this bird species has had die-offs in previous winters, Alaska is seeing higher numbers this year. Researchers with federal agencies have not yet estimated the number; however, they are trying to get a reading of the dimensions and reason for the die-off.

Scientists think this could be happening because of changes in the ecosystem, which have lowered the number of forage fish - those that are eaten by larger predators and birds. Surface water at warmer temperatures, maybe resulting from climate warming or El Niño, may have decreased the stock of herring, juvenile pollock and capelin, according to the AP article.

In about 230 colonies in the state of Alaska, about 2.8 million common murres of breeding age live. They're part of a worldwide population that numbers at 13 to 20.7 million birds. These are land-awkward birds with short, strong wings - as a result, their strength is for "flying" beneath the water, going as far down as 600 feet to forage out fish.

On Whittier beach on Prince William Sound, approximately 8,000 of the birds were found dead, John Piatt at the U.S. Geological Survey's Alaska Science Center said in the AP article. "That's unprecedented, that sheer number in one location is off the charts," he said in the article.

While murres are often affected by winter storms, this year the situation comprises more than that. "The length of time we've been seeing dead birds, and the geographic scope, is much greater than before in other die-off events," Kathy Kuletz with the U.S. Fish and Wildlife Service said in the article. "We're looking at many times that. So possibly a good chunk of the population."

Scientists are still exploring the reasons, but have wondered how murres will fare in the rest of 2016 if their starvation is tied to forage-fish shortages caused by warmer waters, Piatt said in the article.

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