Pinnipeds pitted against steelheads
FOR YEARS , hundreds of California sea lions have colonised the docks in the Oregon port town of Astoria, their loafing brown bodies serving as a tourist attraction and a nuisance begrudgingly tolerated by officials. Authorities have deployed deterrents – including beach balls, electrified mats and a mechanical orca – in futile attempts to scare off the pinnipeds without harming them, because they are protected under federal law.
But when it comes to sea lions that swim their way from the coast to inland rivers, officials are no longer so indulgent. After years of non-lethal hazing efforts, the state wildlife agency is seeking permission to kill them.
The sea lions are a target because of their voracious appetite for threatened and endangered fish. They gobble up so many winter steelhead at Willamette Falls, south of Portland, that state biologists say there’s a 90% chance the fish run will go extinct. If granted a special permit from the federal government, Oregon could trap and kill as many as 92 sea lions at the falls each year.
The conflict pits one protected species against another in an unusual battle that kill-plan proponents say is lopsided in favour of a thriving predator and opponents say makes the species a scapegoat. Although hunting, bounties, habitat loss and pollutants caused the California sea lions’ population to drop below 90 000 in the 1970s, it has steadily risen since the 1972 Marine Mammal Protection Act and numbers nearly 300 000, or what the act calls “optimum sustainable population”.
“The real issue from our standpoint is just trying to find a balance,” said Kurt Schrader, a vete who co-sponsored legislation that would make it easier for Oregon, Washington, Idaho and tribes each year to kill more than 900 sea lions that dine on protected fish in rivers. The prospect of losing the steelhead run, Schrader added, is “just unacceptable to this veterinarian. I love animals, but fish are animals, too”.
Although they are marine mammals, sea lions have proved to be able freshwater inhabitants. After spending the summer breeding in Southern California, the males typically voyage up the coast in the late summer or autumn and stay until May. While there, a few dozen adventurous individuals speed up the cool waterways of the Columbia River along the border of Oregon and Washington, hang a right at the Willamette and then park below Willamette Falls, a U-shaped cascade where Chinook salmon and steelhead stall while waiting their turn at the fish ladder they use to reach upriver spawning grounds.
For sea lions, the spot is a sashimi bar. According to a 2017 state report, more than 15 000 winter steelhead were making it over the falls 15 years ago. This winter, about 1 000 did , the second-lowest number ever counted, said Shaun Clements, a senior policy adviser for the Oregon Department of Fish and Wildlife. At least 25% of the run this year was eaten by sea lions, the agency says.
The pinnipeds at the falls are also eating Chinook salmon in the spring, Clements said, and sea lions have begun to be spotted in other Columbia river tributaries with fragile fish populations.
The state’s proposal follows non-lethal efforts to haze sea lions with firecrackers and rubber bullets, methods “they basically habituate to”, Clements said. Earlier this year, the state carried out an elaborate trap-and-release operation, capturing 11 sea lions when they hauled out to sunbathe on specially placed docks, trucking them to the coast and then letting them loose.
It didn’t work. Each relocated sea lion – which had been marked with brands, shavings or flipper tags – made its way back to Willamette Falls in less than a week. One was relocated and returned twice.
The agency is confident that taking out the sea lions that have figured out the route to the falls – about 40 were spotted there this winter – would curb the problem, because those animals would no longer be able to “share this knowledge with their friends”, as Clements put it.
The Humane Society of the US is dubious. In public comments to the National Marine Fisheries Service, which will rule on the state’s permit application, the organization pointed to the Bonneville Dam on the Columbia. For a decade, Oregon and Washington have been authorized to trap and kill sea lions there to save protected fish. Yet removed sea lions “are rapidly replaced by others,”marine wildlife field director Sharon Young wrote, “since the situation that attracted predators remains unchanged”, resulting in an “endless and ineffective treadmill of death”.
The decision on Oregon’s application is unlikely to come until later this year, at the earliest.
“The proposed congressional legislation, which has bipartisan support in the House and Senate, and has been backed by tribes, sport-fishing organisations and some newspaper editorial boards in the Pacific Northwest, could lead to earlier action, although the measure hasn’t made it past the Senate in previous sessions.
“It is not like we’re going to wipe out sea lions or open a hunting season,” Schrader said of the bill. “It’s about targeted involvement at a critical time.” – Washington Post
IT IS NOT LIKE WE’RE GOING TO WIPE OUT SEA LIONS OR OPEN A HUNTING SEASON. IT’S ABOUT TARGETED INVOLVEMENT AT A CRITICAL TIME