Dead seabirds tied to Statewide die-off

 


Fourteen dead seabirds found on a Portage Cove beach this week are apparently part of a larger statewide die-off that has puzzled biologists since March.

Tim Ackerman came across the dead murres Tuesday along a stretch of beach between the Port Chilkoot Dock and Small Boat Harbor, taking two as potential samples before calling the U.S. Fish and Wildlife Service. “It’s not something you see all the time,” he said.

According to U.S. Fish and Wildlife Service seabird specialist Robb Kaler, the agency started receiving reports of large die-offs of common murres in late March. “It seems pretty widespread, at least in the Gulf of Alaska, but we are getting reports as far east as Sitka and as far west as Unalaska,” Kaler said. They also have been found near Juneau.

Last week, nearly 8,000 dead and dying murres were found on about a mile of beach in Whittier. The murre die-offs in Alaska have made national news, and Kaler reported his interview with the CVN was about the 15th in less than a week.

Although considerably fewer dead birds were found here, it’s still noteworthy that the phenomenon has made its way to the upper Lynn Canal, Kaler said. “Birds die and they wash up on the beach every day, but 14 birds die and wash up on the beach, that doesn’t happen every day.”


Based on necropsies of birds collected since March, biologists have determined the birds are almost certainly starving to death, though it’s unclear why. “We know these birds are starving, but we don’t know the mechanism,” Kaler said. “Is it the warm water, is it redistribution of their food, is something affecting the abundance of their food?”

Above-average sea surface temperatures documented by NOAA could be affecting the amount or distribution of plankton integral to the healthy operation of the ecosystem, leading to a scarcity or movement of the forage fish murres need to survive, Kaler said.

The 100 or so dead murres collected for study since March were emaciated, about 200-300 grams below their average weights, he said. The birds need to eat 10-30 percent of their body weight per day to meet their metabolic rate.

Common murre are black and white diving seabirds, about 15-18 inches long. They live in the North Atlantic and North Pacific.

Murres shouldn’t be near Haines at all, regardless of what time of year it is, said Pam Randles, who has led Takshanuk Watershed Council’s bird observatory program.

Right now, murres should be out at sea above the continental shelf, where water conditions are ideal for plankton and small fish. Otherwise, they should be breeding in outer coastal areas, Randles said.

Randles said that after learning of the dead birds here, she realized that she had seen murres in Lutak Inlet last week. It didn’t even occur to her that the black-and-white birds she couldn’t identify were murres, because they don’t belong here.


“We’re 140 miles from the open ocean,” Randles said.

Randles said the statewide die-offs have “scary implications for the whole food chain.”

The U.S. Fish and Wildlife Service is asking residents to report any dead or dying birds they encounter, as it will help map the magnitude, duration and geographic scope of the murre die-offs, Kaler said.

Report dead or dying birds to the U.S. Fish and Wildlife Service at ak_mbm@fws.gov or 1-866-527-3358.

The proximity of the murres to a dead harbor porpoise found Sunday along Portage Cove will add interest to a planned necropsy of the marine mammal by National Marine Fisheries Service in Juneau.

The porpoise was found at the high-tide line 50 feet west of the former Chilkat Cruises dock. It measured more than five feet and weighed well over 100 pounds, according to witnesses.

Its reported condition makes it seem unlikely the porpoise also died of starvation, said Sadie Wright, an agency biologist in Juneau. Adult harbor porpoises measure about five feet and weigh 135-170 pounds, she said.

Porpoises also can die from harmful algal blooms, including Paralytic Shellfish Poisoning, drowning, and wounds suffered from predation, she said.

Harbor porpoises typically feed on herring and capelin but also can take small salmon, Wright said.

Wright said she was excited to work on the porpoise carcass, as her agency sees few of them. Although the species is common in Alaska, few freshly dead ones are found. The agency received reports of nine dead harbor porpoises statewide in 2015, but was able to retrieve only one. “We feel lucky when we find an intact carcass,” she said.


Carcasses often are predated on by other animals, including bears after they wash ashore, she said.

To report injured or dead marine mammals, call 1-877-925-7773.

 
 

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