PORTLAND -- 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 report from the U.S. Army Corps of Engineers estimates sea lions ate 4,960 salmon and steelhead during the spring of 2009 at the dam near Cascade Locks, Ore.

That compares to an adjusted estimate of 4,927 in 2008.

Sharon Young of the Humane Society of the United States says the statistics show that trying to reduce the numbers of predators does not work when it comes to boosting salmon numbers.

But a companion report from the Oregon Department of Fish and Wildlife estimates that removing the sea lions saved some 1,655 salmon.