Oregon Public Broadcasting

Sea lions eating salmon below Bonneville Dam have been avoiding traps set by state fish and wildlife officials.

In fact, not a single California sea lion has been captured at Bonneville Dam in the last three weeks.

The traps were designed basically as rafts with steel cages on top, says Brian Gorman, a spokesman for the National Marine Fisheries Service.  Gorman says sea lions like to haul their bodies onto jetties, docks, and boats and the traps were designed to take advantage of this behavior.

“But lately, the past couple of weeks, they have not been hauling out on the traps,” says Gorman.  “This is probably due to the fact that they’ve been observing what’s going on.”

In other words, the sea lions seem to have figured out what the traps are and they’re now avoiding them completely.

Gorman says there are three main criteria used to designate a sea lion for permanent removal.

The animal has to be individually identifiable, which usually means it’s been trapped and branded previously.  The sea lion has to have been seen eating salmon or steelhead at Bonneville Dam.  And they have to have resisted attempts at hazing which is usually done in the form of chasing them away with boats, firecrackers, and rubber bullets.

Under these criteria, 85 sea lions were designated for possible removal starting this spring.

But since early March, only eleven of these sea lions have actually been trapped.  Seven of those were diagnosed with pre-cancerous conditions and euthanized.  Two were sent to an aquarium in Chicago, and the final two will be shipped to an aquarium in Brownsville, Texas.

“These animals are very smart and they are very resourceful,” says Gorman.  “And they are very well motivated so it’s not like you’re catching rabbits.”

“Even though they’re not being trapped, they’re continuing to eat salmon that are there below Bonneville Dam,” says Roger Fuhrman, a spokesman for the Oregon Department of Fish and Wildlife.  ODFW is one of the agencies operating the traps.

Fuhrman says his agency turned to trapping after efforts at hazing the sea lions were unsuccessful.

“It discourages them somewhat, but the sea lions continue to move back in,” says Fuhrman.  “And that’s why we requested and received authority to move towards removal of sea lions in the area, because the non-lethal means of moving the sea lions out of the area, the hazing, just wasn’t effective.”

Fuhrman says his agency is concerned about the impact the sea lions are having on both hatchery and wild fish now that they are avoiding the traps.

Oregon and Washington wildlife officials are authorized by the federal government to shoot the problem sea lions on site, but so far they have not done that due to safety concerns.