NOAA Fisheries has approved killing up to 93 sea lions annually at Willamette Falls, where the pinnipeds are consuming as much as 25 percent of wild winter steelhead trout and up to 9 percent of wild spring Chinook salmon.
While the sea lions are protected under the federal Marine Mammal Protection Act, they are eating fish species that are listed as threatened under the Endangered Species Act.
The decision by NOAA Fisheries was reported in the Nov. 19 edition of The Columbia Basin Fish & Wildlife News Bulletin.
After efforts at hazing and non-lethal removal of the California sea lions failed to keep them from hanging out at Willamette Falls, the Oregon Department of Fish and Wildlife (ODFW) applied to NOAA in 2017 for authorization to lethally remove some of them under a MMPA Section 20 permit.
This fall NOAA convened a Willamette Falls Pinniped Task Force, which issued a recommendation on Oct. 15 that the permit be authorized.
Oregon filed for the application because its analyses showed that the high levels of predation by sea lions, including 25 percent of the steelhead run in 2017, meant there was an almost 90 percent probability that one of the upper Willamette steelhead runs would go extinct.
The Oregon Department of Fish and Game noted in a news release that the level of predation of spring Chinook, although at 7 to 9 percent annually, is enough to increase the extinction risk by 10 to 15 percent.
The permit applies only to California sea lions, and not the much larger Steller sea lions, which, according to ODFW policy analyst Shaun Clements, are present at the Falls in growing numbers and prey on white sturgeon. “Current federal law prohibits us from doing anything about that,” Clements said.
Removing the sea lions is about striking a balance between recovery of imperiled salmon and steelhead and the ongoing conservation of sea lions.
According to ODFW predation by pinnipeds also threatens gains made by significant regional investment to improve fish passage at dams, restore fish habitat and implement fishing regulations that prohibit anglers from harvesting wild fish.