What salmon and steelhead runs are at risk from sea lion predation?
Thirty-two wild salmon populations bound for the upper Columbia and Snake rivers are vulnerable to predation by sea lions immediately below dam. The population of greatest concern is the Upper Columbia spring chinook run, which is listed as “endangered” under the federal Endangered Species Act (ESA). Snake River spring/summer chinook, listed as “threatened” under the ESA, are also highly vulnerable to predation by sea lions feeding immediately downriver from Bonneville Dam. Other ESA-listed salmon and steelhead populations passing through the lower Columbia River when sea lions are feeding include lower Columbia River chinook, lower Columbia River steelhead, middle Columbia River steelhead, Snake River Basin steelhead, upper Willamette River chinook and Upper Willamette River steelhead. All are listed as “threatened” under the ESA.
