Saving Salmon

Sea Lion 1, Corps of Engineers 0

By Dan Richardson, 3-08-06

	The Bonneville Dam's spillway, on the Columbia River.

It took a wily and determined sea lion less than a month to beat $1 million worth of new salmon-saving barricades at Bonneville Dam on the Columbia River.

The barricades are called "Sea Lion Exclusion Devices." The Army Corps of Engineers erected the dozen steel SLEDs in early February to protect salmon passing through the dam's fish ladders from voracious sea lions which follow them. The barricades worked...for a while. But now one sea lion — known to official-types as "C-404" — managed to squirm through a 15-inch opening and make himself at home inside the fish ladders.

A Corps press release cites officials who can not say if C-404 will teach other small-to medium-sized sea lions how to enter the fish passages. "C-404 was the first sea lion to enter the fishways last year, but he wasn’t the only one," said Corps biologist Robert Stansell.

The game's not up, however; in addition to the SLEDS, the Corps will attempt to deter sea lions with acoustic devices near fishway entrances that produce a loud sound inaudible to fish but uncomfortable to sea lions. And this week, they've started using pyrotechnic devices, too. Why the aggressive measures? For one thing, though the season is early, biologists have already counted 15 sea lions at the dam, the first one on the Columbia as the salmon and their sea lion predators swim upstream from the ocean.

Want to follow the fish yourself? Check out Bonneville's fish camera.

There's also a well-written story on C-404 at the Vancouver Columbian web page.

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