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The Spokesman-Review Newspaper
Spokane, Washington  Est. May 19, 1883

Sea lion learns to climb fish ladder

Associated Press

BONNEVILLE DAM, Ore. – A sea lion among the many snacking on migratory fish at the base of Bonneville Dam has taken his act to a new dimension.

He has learned to climb the fish ladder, munching a steelhead or two as he goes and putting on quite a show for the visitors and workers who count upstream fish migration from behind a large window.

But fishery managers don’t think he’s cute.

“It’s like Sea Lion Caves without the caves, and without the Oregon coast,” said Curt Melcher, a biologist with the Oregon Department of Fish and Wildlife.

Growing numbers of sea lions have figured out over time that if you just wait at the narrow entrance to the ladders, the fish will come to you.

About 100 have made the 140-mile trip from the Pacific Ocean to the dam in each of the past couple of years.

But working the ladder itself is new, and could cause problems.

The sea lion’s presence and its smell could scare fish away from their passageway to spawning grounds. Melcher said that he has seen salmon avoid a fishway for hours after human hands have left a scent in the water.

State and federal officials are planning to meet this week to decide what to do, if they can do anything.

Hazing or trapping would require special approval from the National Marine Fisheries Service because Congress protected the animals in 1972.

Since then, California sea lions have rebounded from a population of fewer than 1,500 to at least 200,000 on the West Coast.

The U.S. Army Corps of Engineers began intensively monitoring sea lion feeding habits at Bonneville in 2002.

While the sea lions eat only a small part of what commercial gill-netters, sport anglers and tribal fishers take, there is concern about a lack of upstream migration this spring.

At Bonneville, workers have counted fewer than 40 “springers” passing the dam. “It wouldn’t surprise me if sea lions are a contributing factor,” Melcher said.

Dave Clugston, a fishery biologist, said the slow beginning is not too unusual because the river is about three degrees colder than the temperature that usually triggers migration.

The sea lion working the fish ladders was tagged a few years ago and is a known frequent visitor.

There is another fish ladder salmon and steelhead can use to avoid him.