MARINE MAMMAL COMMISSION - Annual Report for 1998 



date, only the state of Washington has requested 

 authority to remove pinnipeds under this provision. 

 Oregon is also monitoring an interaction problem, but 

 is trying to address it using non-lethal means. 



Ballard Locks — The number of winter-run 

 steelhead salmon returning through the Chittenden, or 

 Ballard, Locks in Seattle to spawn in streams empty- 

 ing into Lake Washington declined from nearly 3,000 

 in the early 1980s to fewer than 100 in 1994. During 

 that time, there was a substantial increase in the 

 number of California sea lions congregating near the 

 locks and preying on steelhead. Efforts by the State 

 of Washington and the National Marine Fisheries 

 Service to reduce sea lion predation (e.g., capturing 

 and moving sea lions to distant sites and using acous- 

 tic harassment devices) were largely unsuccessful. 



Pursuant to section 120 of the Marine Mammal 

 Protection Act, in 1994 the Washington Department 

 of Fish and Wildlife sought authority from the Service 

 to lethally take individually identifiable California sea 

 lions preying upon winter-run steelhead migrating 

 through the Ballard Locks. The state also asked that 

 a pinniped-fishery interaction task force be established 

 as required under section 120(c). 



The Ballard Locks Pinniped-Fishery Interaction 

 Task Force was established in September 1994 and on 

 22 November 1994 it forwarded its recommendations 

 to the Service. As discussed in previous annual 

 reports, it recommended, among other things, that sea 

 lions preying on steelhead in the vicinity of the 

 Ballard Locks be removed, preferably by non-lethal 

 means. It also recommended that lethal removal be 

 authorized if facilities were not available to hold 

 depredating sea lions and if predation exceeded 10 

 percent of the returning steelhead in any consecutive 

 seven-day period. 



Based on the task force recommendations and 

 comments received from the Marine Mammal Com- 

 mission and others, the Service on 4 January 1995 

 authorized the Washington Department of Fish and 

 Wildlife to lethally remove individual California sea 

 lions observed preying on winter-run steelhead migrat- 

 ing through the Lake Washington ship canal in the 

 vicinity of the locks. 



The authorization, valid until 30 June 1997, also 

 specified that the state must submit a report on its 

 authorized activities by 1 September each year. The 

 Washington Department of Fish and Wildlife submit- 

 ted its first report to the National Marine Fisheries 

 Service on 31 August 1995 describing actions taken 

 during the 1994-1995 winter steelhead run. The 

 report noted that no sea lions were killed during the 

 run; however, three animals seen eating steelhead 

 were captured, held in captivity until the end of the 

 run, and then transported to the Strait of Juan de Fuca 

 and released. One of the captured sea lions was held 

 for more than four months before being released. 



The Ballard Locks Pinniped-Fishery Interaction 

 Task Force met to review the state's 1995 report and 

 concluded that its 1994 assessment of the simation re- 

 mained valid {i.e., that "Lake Washington wild steel- 

 head are near extinction for a number of reasons, one 

 of which is their vulnerability to predation by sea 

 lions at the Ballard Locks"). 



To avoid a "significant negative impact" on the 

 steelhead population, the task force recommended that 

 any individually identifiable sea lion observed killing 

 salmon or steelhead in 1995 or previous years should 

 be removed at the earliest oppormnity if resighted in 

 the Puget Sound area between Everett and Shilshole 

 Bay. The task force recommended that such animals 

 be permanently removed, either to captivity or by 

 lethal means. The task force further recommended 

 that animals observed preying upon steelhead for the 

 first time after 1 October 1995 should be taken into 

 captivity for the remainder of the run or be lethally 

 removed if funding for captive maintenance were not 

 available. The task force recommended that animals 

 seen merely foraging in the area on three or more 

 days should be removed to captivity but not killed. 



Subsequently, the Service revised its letter of 

 authorization to the Washington Department of Fish 

 and Wildlife to redefine the term "predatory" as 

 applied to sea lions, thus eliminating the predation 

 rate "trigger" that had been included in the original 

 letter of authorization. Under the new definition, a 

 predatory sea lion is one that (1) is an identified 

 animal bearing a brand, tag, or distinguishable natural 

 mark; (2) has been observed by biologists preying on 

 returning steelhead in the inner bay area of the Lake 



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