Steelhead supplementation in Idaho rivers: summary report for 1993-1999: to evaluate the feasibility of using artificial production to increase natural steelhead populations and to collect baseline life history, genetic and disease data from natural steelhead populations

摘要

The Steelhead Supplementation Study has conducted field experiments since 1993 that assess the ability of hatchery stocks to reestablish natural populations. We have stocked hatchery adult steelhead Oncorhynchus mykiss trapped at Sawtooth Fish Hatchery in Beaver Creek yearly and Frenchman creeks when enough fish were available. We stocked Dworshak Hatchery stock fingerlings in the South Fork Red River from 1993 to 1996 and smolts in Red River from 1996 to 1999. Although results from all experiments are not complete, preliminary findings indicate that these hatchery stocks will not reestablish natural steelhead populations. We focused most of our effort on monitoring and evaluating wild steelhead stocks. We operated a temporary weir to estimate the wild steelhead escapement in Fish Creek, a tributary of the Lochsa River. We snorkeled streams to monitor juvenile steelhead abundance, captured and tagged steelhead with Passive Integrated Transponder (PIT) tags, and recorded stream temperatures in the Clearwater and Salmon River drainages. We operated screw traps in five to ten streams each year. We have documented growth rates in Fish and Gedney creeks, age of parr in Fish Creek, Gedney Creek, Lick Creek, and Rapid River, and documented parr and smolt migration characteristics. This report summarizes our effort during the years 1993 to 1999.