Sea Lion Return
by Steven Johnson
Maybe wood panels will help.
That's the newest tactic wildlife managers are using to prevent foraging sea lions from gobbling up salmon and taking a bite out of ratepayer investments in endangered fish species.
Officials from the Army Corps of Engineers have placed wood panels on top of bar-like devices at Bonneville Dam to prevent sea lions from climbing onto the ladders that fish use to bypass hydroelectric turbines.
Success or failure? Too early to tell.
When workers lifted sea lion exclusion devices from the dam's north shore fishway entrance, "an attempt to haze the sea lion out of the collection channel on March 15 ended with unclear results," the Corps said in its first 2016 update on sea lion activity.
The pinnipeds are a headache because they return every year at this time to the Columbia River between Oregon and Washington in search of salmon.
Bonneville Power Administration customers, which include electric co-ops in a four-state region, forked out $782 million in 2014 on fish and wildlife programs -- about one-third of BPA's wholesale power costs.
According to the Corps, sea lions consumed 10,859 salmon and steelhead at Bonneville Dam in 2015, or more than 4 percent of adult salmon and steelhead counted there between January 1 and May 31.
So far this year, Steller sea lions are more numerous than California sea lions, the Corps noted, but both have the potential to cause serious damage to spring runs of fish listed under the Endangered Species Act.
The highest count of both sea lion types occurred on March 9, when observers detected 45 sea lions around the dam. Markings showed that most were repeat scavengers from previous years, the Corps said.
In addition to the wood panels, wildlife officials have the power to kill selected sea lions. About 76 have been removed since 2006.
The Columbia River Inter-Tribal Fish Commission and the U.S. Department of Agriculture also are using boats to haze and frighten sea lions from establishing a beachhead at Bonneville Dam. Efforts began in early March, again with mixed results.
"Thus far hazing has been effective toward the Stellers that appear a little more skittish and. . . new-to-Bonneville animals," the Corps said. "However, Stellers continue to haul out and sleep on Tower Island when the hazers are not present."
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