The number of dead common murres showing up on Alaska’s beaches is growing, and the scale of the die-off is now on par with the grounding of the 1989 Exxon Valdez in Price William Sound when 22,000 birds were collected.
Heather Renner with USFWS says it is already one of the largest die-offs in history and, unlike when the tanker went aground, not many people have gone out to remote beaches to survey for dead seabirds.
“The exactly same number is purely a coincidence,” said Renner. “Our number is changing every day as people call in more reports. But certainly there was a lot of effort put into searching beaches then. Now people are just calling in and telling us about them. And we haven’t gotten a chance to look at much of the remote coastline.”
Renner told the Alaska Marine Science Symposium that dead murres started showing up on beaches last summer, but since those numbers were spread out over a large area they weren’t noticed until the thousands started showing up on beaches in January.
“It was 10 times what it normally is, but you still had to walk a long ways before you found a carcass,” said Renner. “Then suddenly since Christmas you can’t walk a beach without finding them everywhere. You see them along the Seward Highway here in Anchorage. They’re foraging in Cook Inlet, which they never do. But there’s dead murres on the ground everywhere, and it’s hard not to notice them.”
The reason for the dead birds is still a mystery, but Renner says both the huge area that they are being found in and the fact that it began last summer and has continued over a long time indicates it might be the result of a change in the food web caused by the unusual “Blob” of warm water pressed up against Alaska’s coast.
“I think it rules out short-term acute events like immediate poisoning events. I think it suggests something more related to the food web structure,” said Renner. “But there are a lot of hypotheses. That certainly these things all contribute to each other, so at a time when you have a big storm you have a large pulse of numbers because the birds are stressed and weakened already.”
Murres are found farther down the West Coast, in areas where the water is much warmer, but scientists think it was the abrupt change in water temperatures and conditions that may have changed the food web making it impossible for the birds to survive.
Researchers have now examined more than a hundred of the birds but have seen no sign of toxins in their stomach contents, but then again, Renner said, the birds were so starved that there was hardly anything in their stomachs to analyze.