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Development of a Systemwide Predator Control Program, Section I : Northern Squawfish Management Program Implementation, 1994 annual report.

Technical Report ·
DOI:https://doi.org/10.2172/666199· OSTI ID:666199
 [1];  [2]
  1. S.P. Cramer and Associates, Inc., Gresham, OR
  2. Columbia Basin Fish and Wildlife Authority, Portland, OR
The authors report the results from the forth year of a basinwide program to harvest northern squawfish (Ptychocheilus oregonensis) in an effort to reduce mortality due to northern squawfish predation on juvenile salmonids during their emigration from natal streams to the ocean. Earlier work in the Columbia River Basin suggested predation by northern squawfish on juvenile salmonids may account for most of the 10--20% mortality juvenile salmonids experience in each of eight Columbia and Snake River reservoirs. Modeling simulations based on work in John Day Reservoir from 1982 through 1988 indicated it is not necessary to eradicate northern squawfish to substantially reduce predation-caused mortality of juvenile salmonids. Instead, if northern squawfish were exploited at a 10--20% rate, reductions in numbers of larger, older fish resulting in restructuring of their population could reduce their predation on juvenile salmonids by 50% or more. Consequently, the authors designed and tested a sport-reward angling fishery and a commercial longline fishery in the John Day pool in 1990. They also conducted an angling fishery in areas inaccessible to the public at four dams on the mainstem Columbia River and at Ice Harbor Dam on the Snake River. Based on the success of these limited efforts, they implemented three test fisheries on a multi-pool, or systemwide, scale in 1991--a tribal longline fishery above Bonneville Dam, a sport-reward fishery, and a dam-angling fishery.
Research Organization:
S.P. Cramer and Associates, Inc., Gresham, OR
Sponsoring Organization:
BPA (Bonneville Power Administration (BPA), Portland, OR)
OSTI ID:
666199
Report Number(s):
DOE/BP-24514-1; ON: DE98005160; CNN: Contract 94BI24514
Country of Publication:
United States
Language:
English