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States get Set for Sea Lion Trapping;
Zoos, Aquariums Show Interest

by Columbia Basin Bulletin
Chinook Observer, March 19, 2008

COLUMBIA RIVER - The trapping of California sea lions below Bonneville Dam is set to begin in the coming weeks with some of the animals, potentially, lethally removed and others finding their way to zoos and aquariums.

The states of Idaho, Oregon and Washington are awaiting word on whether they will receive permission from the NOAA Fisheries Service to lethally remove sea lions preying on federally protected salmon and steelhead below the dam.

The states in December 2005 filed an application for lethal take authority under the Marine Mammal Protection Act. Its Section 120 allows the removal of "individually identifiable pinnipeds (seals and sea lions) that are having a significant negative impact on the decline or recovery of salmonids listed under the Endangered Species Act...."

A NOAA decision on the application is expected later this month with completion of a final environmental assessment of four alternatives for reducing sea lion impacts on salmon. A draft NOAA environmental assessment released in January outlined a "proposed" action that would let the states use lethal removal only for individual sea lions that are not scared away by non-lethal deterrence methods and have been observed taking salmon.

The document estimates that 30 nuisance animals would be killed annually under the proposed alternative.

The trapping is intended to expand the number of California sea lions that can be positively identified. Animals trapped initially would be branded and hauled downstream for release at Astoria, Ore., according to Bryan Wright, Oregon Department of Fish and Wildlife marine predation biologist. If lethal removal authority is received, offending animals that are trapped could be killed by lethal injection. The proposed action also includes shooting as a removal option.

The ODFW has one trap that it has been using to brand animals at Astoria as a part of ongoing research. It was recently moved up to Bonneville, though not set, and marine mammals have already been seen entering the device. The idea is to allow the sea lions to become comfortable with the trap as part of their environment.

Funding received from the Bonneville Power Administration has allowed the states to order two new traps, and a trapping barge. Once the barge arrives in early May, the California sea lions would be branded and released at the dam, or euthanized.

If removal is approved, some of the pinnipeds might well land in zoos or aquariums.

"As soon as we got the states' application, facilities raised their hands," said NOAA Fisheries' Garth Griffin. "I've been pleasantly surprised" at the level of interest from captive display facilities.

"They're at a point where they need an infusion in their captive breeding programs" to increase the genetic diversity, he said. "They really haven't taken a lot of animals out of the wild in a long time." The MMPA, passed in 1972, prohibits, with certain exceptions, the take of marine mammals in U.S. waters and by U.S. citizens on the high seas, and the importation of marine mammals and marine mammal products into the United States.

Historically California sea lions were rarely spotted upriver as far as Bonneville, but the past seven or eight years they have become a strong presence below the dam. As many as 100 have been seen in recent springs preying on salmon as they search for fish ladders to continue their spawning migration. Last year observers employed for a U.S Army Corps of Engineers study saw sea lions take more than 3,500 salmonids. Most were spring chinook salmon, which includes Upper Columbia and Snake River stocks that are ESA listed.

The states are working with the Corps, enforcement agencies, an animal care committee and other groups to create a plan to address safety issues and coordination should lethal removal be approved, according to the March 13 "Status Report - Pinniped Predation and Hazing at Bonneville Dam." Logistics for a holding facility are also being explored in the event some of the pinnipeds are ticketed for zoos or aquariums.

Many male California sea lions forage north from their Southern California breeding grounds. Few ventured far up the Columbia until the turn of the century. Their growing presence at Bonneville, 145 miles from the mouth of the Columbia, drew the attention of NOAA Fisheries, which is charged with protecting listed salmon. The Corps, which operates the dam, launched a monitoring effort in 2002 to evaluate sea lion impacts on migrating salmon.

So far this year 18 different California sea lions have been spotted below the dam, as have 12 Steller sea lions and two harbor seals. The Steller presence is lessening, and more California sea lions are arriving in recent days, according to the March 13 report from the Corps.

The salmon presence is also growing as the tip of the upriver spring chinook run begins to reach the dam. Only three salmon were counted passing the dam's fish ladders in February. So far 28 have passed in March, including 10 on Wednesday. The upriver spring chinook passage normally builds slowly to a peak in late April. The preseason forecast is for an adult return of 269,000.

Observers on the dam so far have seen 23 chinook and 138 steelhead taken by the pinnipeds, as well as 247 unidentified fish that are likely also salmonids. The report stresses that all of its data are preliminary and will likely change to some degree after further analysis and proofing.

The California sea lions' targets have been primarily steelhead but with the arrival of chinook they have been catching more salmon, according the Corps' Robert Stansell, who heads up the sea lion research.

While the California sea lions target salmon, the Steller sea lions focus on white sturgeon. So far this year observers have tallied 421 sturgeon being taken, including 15 estimated to be larger than 5 feet long. That total has already surpassed last year's total of 360, though fewer large sturgeon are being taken by the Stellers this year, according to the report.

Meanwhile, boat-based hazing of the pinnipeds by the states continues two to five days per week in an effort to deter predation. Dam based harassment by U.S. Department of Agriculture Wildlife Service agents began March 3 is conducted seven days a week.

For information about Columbia River sea lions go to (

Related Pages:
Survival of Snake River Salmon & Steelhead data compiled by, July 2004

Columbia Basin Bulletin
States get Set for Sea Lion Trapping; Zoos, Aquariums Show Interest
Chinook Observer, March 19, 2008

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