Contact: Brian Gorman FOR IMMEDIATE RELEASE
3/13/96
The Commerce Department's National Marine Fisheries Service today authorized the state of Washington to kill predatory California sea lions that threaten steelhead trout returning to Seattle's Lake Washington to spawn, saying all other means of deterring sea lions from killing the steelhead have failed.
In a letter of authorization to Washington State's Department of Fisheries and Wildlife, the fisheries service said that starting March 16, the state may kill any "predatory" sea lion that (1) can be individually identified and has been observed killing steelhead at the locks, (2) has been observed foraging for steelhead at the locks any time after Jan. 1, 1994, when underwater noise-making devices were installed, and (3) is observed foraging at the locks during this year's steelhead season. The season began Jan. 1 and runs through May 31.
According to the fisheries service, three sea lions currently meet these standards and thus could be killed if they return to the locks and are observed foraging. Two other sea lions would meet the standard if they are observed to eat a steelhead during this year's season or next.
The letter generally endorses the recommendations made late last year by a special task force convened specifically to address the problems of sea lion predation on steelhead at the locks. The 19-member task force was convened under changes to the Marine Mammal Protection Act made in 1994 and is composed of scientists and representatives of conservation and fishing organizations, treaty Indian tribes and Washington State government agencies.
The changes in the act made possible for the first time "lethal removal" of sea lions at the locks, and in 1994 the state asked the fisheries service for that permission. In January 1995, the state was granted permission to capture and kill sea lions at the locks, but only under special circumstances. Steelhead-eating sea lions could be killed, but only if the state could demonstrate that it was impractical to hold a captured animal temporarily. Captures could take place only if all the sea lions at the locks were together killing at least ten percent of the steelhead passing through the locks during a seven-day period.
One animal, designated Number 17 by fisheries service observers, was removed from the locks last season. It was held in captivity for the duration of the steelhead run at a cost of $120,000, including the one-time cost of building a holding pen. Number 17 was released to the wild last June, after an estimated 126 fish swam back to Lake Washington to reproduce.
Number 17, which at the time of its capture last year weighed 870 pounds, now weighs about 1100 pounds. It returned to Ballard Locks in early January.
"Lethal removal of sea lions is a solution of last resort," said William Stelle, head of the fisheries service's Northwest regional office in Seattle. "But it is clearly the only choice remaining. The alternative is to watch the steelhead returns drop to zero."
Stelle said simply removing a predatory sea lion from the locks temporarily, as was done with Number 17, isn't a practical solution.
"The cost of temporarily holding a sea lion is not the major factor here," Stelle added. "Any sea lion that is captured and released -- as Number 17 has clearly demonstrated -- is only going to return next year, bigger, more experienced and harder to capture again," he said.
For a decade, the fisheries service has attempted to drive away foraging sea lions at the locks, using firecrackers, underwater noises, rubber-tipped arrows and foul-tasting fish. None of these methods has worked. In 1990, six sea lions were captured and trucked to California, where they were released in coastal waters. Three of the animals returned to Puget Sound within 45 days.
Scientists with the fisheries service said their chief worry is that sea lions, like Number 17, that exhibit predatory behavior and cannot be deterred by underwater-sound-making devices, will encourage less experienced sea lions to remain at the locks, forage for steelhead and ignore the underwater "acoustic barrier" that has been operating there since December. They said removing predatory animals like Number 17 would reduce the chances of future foraging behavior by other sea lions.
The fisheries service says that although other factors may be involved in the diminishing number of adult steelhead returning to spawn, sea lion predation is the primary cause.
Historically, steelhead returned to Lake Washington to spawn in substantial numbers, typically around 1,600 a year. But beginning in the mid-1980s, California sea lions started arriving at the locks and eating steelhead at an increasing rate and the size of returning runs has been declining ever since. In 1994, only 70 returning steelhead were counted at Ballard Locks, the lowest return on record.
The California sea lion population, by contrast, is robust, numbering as many as 1,000 animals in Puget Sound alone, according to estimates by marine mammal biologists. California sea lions range along the entire West Coast of the United States. Their total U.S. population is thought to be more than 161,000 animals.