Sea lions removed, but salmon toll rises

Killing or removing 25 California sea lions over the past two years has not reduced the toll on salmon at the base of Bonneville Dam in the Columbia River.

A new report from the U.S. Army Corps of Engineers estimates sea lions ate 4,960 salmon and steelhead this past spring — 2.4 percent of the fish passing the dam located near Cascade Locks, Ore. That compares to an adjusted estimate of 4,927, or 2.9 percent of the run, in 2008.

And while the number of California sea lions was down — 54 this year compared to 82 in 2008 — the average number of salmon eaten by each one was up, along with the number of Steller sea lions — 26 this year compared to 17 last year.

Sharon Young of the Humane Society of the United States said the numbers show that trying to restore salmon by killing predators does not work at a place like Bonneville Dam.

"You have to address the root issues causing problems for the salmon," such as the dams, fishing, habitat loss and irrigation withdrawals, she said.

"Obviously, if predation were the primary issue in the recovery of salmon, we wouldn't be seeing the run size fluctuating like this. The run size fluctuates due to oceanic variables to which the animals are exposed."

The report showed spring runs steadily increasing from 88,474 in 2007 to 186,060 in 2009, while the numbers of salmon eaten by sea lions stayed about the same — 4,335 in 2007 when no sea lions were removed and 4,960 this year after 25 were trapped and killed or sent to aquariums.

A companion report from the Oregon Department of Fish and Wildlife estimates that removing the sea lions doing the most damage saved some 1,655 salmon.