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Aug. 14, 2020

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Removal of sea lions clears way for Willamette wild winter steelhead

Run back from brink of extinction

By , Columbian staff writer
Published:
2 Photos
In this 2018 photo, a California sea lion peers out from a restraint nicknamed "The Squeeze" near Oregon City, Ore., as it is prepared for transport by truck to the Pacific Ocean about 130 miles away. That effort, along with lethal removal, has cleared the way for winter steelhead on the Willamette.
In this 2018 photo, a California sea lion peers out from a restraint nicknamed "The Squeeze" near Oregon City, Ore., as it is prepared for transport by truck to the Pacific Ocean about 130 miles away. That effort, along with lethal removal, has cleared the way for winter steelhead on the Willamette. (Gillian Flaccus/Associated Press) Photo Gallery

Wild winter steelhead are beginning to pass over Willamette Falls in Oregon City, and for the first time in many years, they are not having to pass a deadly wall of predators. In recent years this native run of steelhead has been hammered by sea lions to the point that the run was in peril of extinction.

Until last winter. That was when fish and wildlife managers were, for the first time, allowed to use lethal methods to remove problem pinnipeds.

Since 2006 California sea lions have been kegging up at the falls and eating an alarming number of the steelhead, which are federally listed as an endangered species. In 2017 only 822 steelhead made it past the sea lions. The run was calculated to have an 89 percent chance of going extinct.

The number of steelhead passing the falls rose to 3,202 in spring of 2019, after a number of sea lions were removed.

“They removed 12 of the habitual offenders last year,” said Rick Swart, a public information officer for the Oregon Department of Fish and Wildlife. “The hope is that by removing those there would be fewer that return early in the season, right about now.”

In all, 33 California sea lions were euthanized in 2018-19 at Willamette Falls.

Fisheries managers will be watching closely this year to see if removing the core of problem sea lions had the desired effect of breaking the cycle of predation.

All marine mammals are very intelligent and quickly pass learned behaviors on to other animals. The first sea lions to target the steelhead soon taught others to do the same.

Will there be less pinnipeds at the falls this year? So far that is the case.

“We saw some pretty positive results at Willamette Falls because we were able to get on top of the issue,” said Sheanna Steingass, Marine Mammal Program Leader at the Oregon Department of Fish and Wildlife . “We started lethal removal last December at Willamette Falls after years of hazing and trapping with not very good results. This time last year we had several animals up at Willamette.”

“This year we have not seen any California sea lions at Willamette Falls and based on our modeling of when the animals arrive, we’re hoping that we may not see animals until late March.”

Steingass reports that the risk of extinction for the steelhead has been reduced to 11 percent.

“Assuming we can keep up the efforts that should continue to drop as well. We’re watching those fish counts, and really getting a good idea about how this is impacting the runs.”

The state is restarting the program for this year.

Operations on the Willamette are the result of a permit that was granted in November 2018. California sea lions can be removed within the permit guidelines if they are sighted twice below the falls, or if they are seen actually eating a salmon.

Bonneville Dam sea lions

There is another permit making its way through the system that should make managing marine mammals at Bonneville Dam easier. That permit is a direct result of the passage of US Senate Bill 3119, the Endangered Salmon Predation Prevention Act, which will make it easier to remove animals that create problems in the lower Columbia River.

The permit was requested by state fisheries managers from Idaho, Oregon, Washington, the Columbia River Intertribal Fish Commission, and other partners.

“What that does is allow for proactive removal of animals that are upriver of river mile 112 On the Columbia,” said Steingass. “Hopefully it will prevent situations like Bonneville or Willamette where animals accumulate over years.”

“The Willamette was not an issue until 2006, and then it takes so long to apply for a permit at a particular site, the animals accumulate. By the time you are able to deal with it you are dealing with 40 animals instead of three.”

The new permit would call for the ability to remove more animals from the mainstem Columbia and its tributaries up to the Oregon/Washington state line. It would also include Steller sea lions for the first time. Until now only California sea lions could be removed.

Stellers bring their own set of troubles.

“Stellers have historically consumed a lot of sturgeon,” said Steingass. “But now that the abundance and size of sturgeon has decreased, they have begun to eat more and more salmon. Now the major consumers of salmon at Bonneville are the Stellers.”

The Bonneville guidelines for removing sea lions currently is rather vigorous.

“To qualify the animals must be sighted or trapped five times by Army Corp staff or respective agencies, or be directly observed eating salmon,” said Steingass. “They need to be identifiable. For that we brand them or give them flipper tags.”

The new permit, which is expected to be granted sometime next fall, will make it far easier for managers to remove sea lions that take up pinch-points at dams and in tributaries to intercept fish.

While anglers have been waiting for years to see fisheries managers gain the tools they need to get a handle on marine mammal predation, these operations are geared toward helping federally listed endangered fish, according to Swart.

“The main goal is to stop predation on upper Willamette steelhead,” he said.

While many advocates for wild fish are cheering recent developments, many anglers want to see more fish in the rivers to catch, especially spring Chinook, which the sea lions prize. They are hoping to see an uptick in fish runs that will benefit them, but Swart says that is not the point of these programs

“It isn’t a goal to reduce predation on hatchery spring Chinook,” he said. “Spring Chinook are not the priority. But, if you are taking sea lions out in February, March, April and May, you are also reducing predation on spring Chinook.”

“We are not doing this to increase people’s creel.”

However, if better hatchery returns are an eventual outcome of reduced predation, few anglers will complain.

Columbian staff writer
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