Sea Lions Paddle Inland for Shrinking Salmon Stock

More than 120 miles inland at the foot of Willamette Falls, where the last of the spring chinook salmon are leaping upstream, it’s a sea lion smorgasbord.

A fat black sea lion nicknamed Buddy dives for lunch just feet from a trap set up to catch him--a large metal cage on blue floats.

Buddy could be captured and transported out to sea, but the 800-pound pinniped is hungry, smart and elusive. He knows where the pickings are easy, and he’ll be back.

“We’re finding increasingly that seals and sea lions are coming way upriver, 100 miles or more, to prey on salmon,” said Brian Gorman, spokesman for the National Marine Fisheries Service. “They are becoming bolder, I think in part because of their population growth.”

Sea lions and seals in the Northwest are thriving, while one of the staples of their diet, salmon, are dwindling. That has resulted in sea lions going to great lengths, literally, to feast on their prey.

They are taking enough of a bite out of threatened and endangered salmon and steelhead runs that the Fisheries Service plans to make recommendations to Congress later this month that would let fishery managers take a tougher stand against these rogue sea mammals--including possibly killing them.

“We’d rather not see the sea lions taking the potentially endangered fish,” said Robin Brown, marine mammal specialist for the Oregon Department of Fish and Wildlife.

“That isn’t to blame the decline of the fish on the sea lions,” he said. “But it’s an approach to protect the fish population that’s in a poor state. And the sea lion population is in a very healthy state.”

According to the Fisheries Service, there are about 180,000 California sea lions on the West Coast, and their number is growing by about 5% a year. Harbor seals number about 75,000.

Most of the aggressive sea lions found at inland sites are non-breeding males, weighing 700 to 800 pounds. Smaller females and pups tend to stay near their rookeries off the California coast.

Sea lions were spotted at Willamette Falls as early as the mid-1980s but have become an increasing problem in recent years.

“We’ve been monitoring the numbers and their activities since 1995, and generally they show up in late March-early April and they’ll stay through mid- to late May,” Brown said.

At first, there were just one or two repeat visitors each spring. Now they number five or six, he said. They take a couple of hundred chinook salmon and steelhead at the falls each year.

“They’re smart. They know where lunch is being served,” said Glen Spain, regional director for the Pacific Coast Federation of Fishermen’s Assns. in Eugene.

Fisheries experts compare the situation at Willamette Falls, 13 miles southeast of Portland, to previous sea lion troubles at Ballard Locks in Seattle.

“We tried foul-tasting fish, rubber-tipped arrows, firecrackers, and we even tried capturing them and trucking them to California, but they came back in a matter of weeks,” Gorman said.

“We finally managed to get authorization to capture and permanently remove the sea lions,” he said. “The state wanted to kill them.”

Sea World in Orlando, Fla., came to the rescue, accepting three refugees, although one later died of an infection.

“Since then, we’ve had no real trouble at the Ballard Locks, which lends credence to our belief that most of the predation at restricted areas is caused by a minority of very aggressive sea lions, which if removed can at least in the short term eliminate much of the problem,” Gorman said.

The Fisheries Service plans to recommend that Congress “liberalize” the federal laws that protect sea lions and seals to address these types of problems.

“What they’re proposing is that the state or federal agency be allowed to remove a small number when you have them in an unusual situation,” Brown said. “It probably would be live capture and euthanization with drugs.”

Biologists and fishermen agree that seals and sea lions are not to blame for the decline of salmon and steelhead runs.

Culprits include the degradation of their habitat from logging, grazing and urban development, water diversion for irrigation, loss of passage because of dams and overharvest in some cases.

“The concern is that once these stocks get to such low levels, if seals and sea lions in some of the bays are taking 50 to 100 of those, it becomes a question for the manager whether it’s an acceptable loss,” Brown said.

The problem at Willamette Falls is that the timing of the sea lion feast coincides with the peak passage of wild winter steelhead, which have been proposed for listing under the Endangered Species Act.

“What sea lions are doing is making a perilous situation even riskier,” Gorman said. “Instead of healthy populations of fish that could absorb the loss, we have sick populations that could be threatened out of existence.

“There are plenty of instances,” he said, “in which two or three sea lions at the mouth of that river could all but eliminate that season’s run.”