Northwest sea lion managers report they have now lethally removed a total of 35 Stellers and 29 Californias under summer 2020’s federal authorization as part of a bid to reduce pinniped predation on ESA-listed salmon, steelhead and other stocks in the Columbia system.
About 85 percent have been removed from Bonneville Dam, the remaining 15 percent at Willamette Falls.
WDFW Region 5 manager Kessina Lee provided the update this evening during the first of six regional virtual open houses to be held by the agency this month and next.
She also reported that 25 of the larger Steller sea lions remain at Bonneville Dam and that removal “season” continues through mid-November.
This year’s operations also expanded to five months from 2020’s two.
“We’re really encouraged by how it’s going so far,” Lee said about staffers adapting to handle the animals.
With the OK to also perform sea lion removals in tributaries where listed salmon and steelhead spawn, she added that 2022 will see pilot work performed in those smaller waters, but that will require acquiring a new boat and equipment.
“It’s not exactly a very mobile operation at this point,” said John Edwards, WDFW Columbia River pinniped biologist, of the setup at Bonneville.
He said that increased funding from the state legislature helped expand this year’s efforts and that a request has been sent to Congress to provide money for the tributary work.
“We know impacts are happening in other parts of the river than just Bonneville,” said Edwards.
The federal permit allows WDFW, ODFW, IDFG and CRITFC to remove 176 Stellers and 540 Californias over five years.
Both figures are well within the so-called “potential biological removal” limit for each species.
Edwards said the idea with removing sea lions at chokepoints was to minimize how many return in the future, given the species’ learned behavior.
Sea lions have been estimated to consume as much as 44 percent of the spring Chinook run up the Columbia, according to ODFW, and at least one of the Willamette River’s wild winter-run steelhead runs faced an 89 percent risk of extinction before 33 Californias were removed by ODFW at Willamette Falls in 2018 and 2019 under a separate state permit.
Prior to Congress’s amending of the Marine Mammal Protection Act in late 2018, removals had been limited to California sea lions at Bonneville.
An online tool launched last year allows users to share information on when, where and how many pinnipeds they saw; what the marine mammals were doing – e.g., “consuming prey (not stolen from an angler); consuming prey (stolen from an angler),” etc. – provide photos; and share other details of their observation.