Wildlife biologists in Oregon and Washington say hungry sea lions at the mouth of the Columbia River are apparently responsible for the rapid decline in numbers of sturgeon in the river.
The Oregonian reports that sharply reducing sport and commercial sturgeon fishing on the lower Columbia is the only variable that officials can control to save the fish.
Oregon biologists estimate that sea lions below the Bonneville Dam killed about 7,000 sturgeon last year older than five years. The area below the dam favored by the older, breeding sturgeon.
State and federal agencies say hazing, trapping and removing sea lions are not effective ways to control their predation. Shooting sea lions was recommended last year by a federal advisory group, but killing was stopped in November by court order.