Hungry Sea Lions Pile Into The Columbia River

California sea lions are literally piling into Astoria's East Mooring Basin. They've taken over every square foot of the boat docks, and they're even lying on top of each other for lack of space.

The latest sea lion count in the marina tallied a record 2,340 – a "mind-boggling number," according to Bryan Wright of the Oregon Department of Fish and Wildlife.

Meanwhile California is seeing starving sea lion pups washing up on shore.

There's probably a connection there, according to Nate Mantua, research scientist with the National Oceanic and Atmospheric Administration.

Mantua said unusually warm water temperatures in the Pacific stretching from the Gulf of Alaska all the way to Mexico have likely affected the fish seals and sea lions typically eat in the ocean. The population of sardines, one of the staples of their diet, is experiencing a major crash. Meanwhile, millions of smelt returned to the Columbia River this year.

"The male sea lions that migrate up the coast in the spring and winter, they're probably having a hard time finding food in the usual places where they forage," he said. "Whereas the lower Columbia River has a relative abundance of food with the smelt run and the early stages of the salmon run."

Wright said biologists have noticed a jump in sea lion numbers in the lower Columbia River that corresponds with several years of strong smelt runs in the river.

The usual sea lion counts in Astoria's East Mooring Basin ranged from 100-300. Last year set a record with 1,420 sea lions. This year's numbers shatter that record.

"It's doubled and then doubled again and then increased even more, not quite doubling this year," Wright said. "This year we've had a record number of California sea lions in the lower river near Astoria, following on the last two years, which at the time were historic numbers."

Steve Jeffries, marine mammal biologist with the Washington Department of Fish and Wildlife, photographed a huge group of 6,422 harbor seals at the mouth of the Columbia last month. He said seals also follow the smelt runs, which have been significant the past two years.

He noted the California sea lion population of around 300,000 "is about as large as it's ever been," so changes in food availability are more likely to have an impact. In California, warm water has shifted the sea lions' food base farther from shore, where females have their pups, he said.

"The females have to forage farther out, and they basically abandon their pups because they have to search farther and longer," he said. "Their normal prey they eat has been disrupted. So they spend more time foraging and at some point their pups have to nurse."

Wright said a big question now is how many sea lions will stay in the Columbia River and eat returning spring salmon. Oregon and Washington have authorization to kill some of the sea lions to protect threatened salmon and steelhead at Bonneville Dam.

A new bill sponsored by U.S. Rep. Kurt Schrader, D-Ore., and U.S. Rep. Jaime Herrera Beutler, R-Wash., would allow tribal members to kill sea lions and harbor seals to protect fish.