Lake Roosevelt Fisheries Evaluation Program; Meadow Creek vs. Lake Whatcom Stock Kokanee Salmon Investigations in Lake Roosevelt, Annual Report 2002.

McLellan, Holly

United States. Bonneville Power Administration.

关键词: British Columbia;    Adults;    Columbia River;    Males;    Salmon;   

DOI  :  10.2172/963061
RP-ID  :  DOE/BP-00005756-4
RP-ID  :  5756
RP-ID  :  963061

美国|英语

来源: UNT Digital Library

【 摘 要 】

Lake Whatcom, Washington kokanee have been stocked in Lake Roosevelt since 1987 with the primary objective of creating a self-sustaining fishery. Success has been limited by low recruitment to the fishery, low adult returns to hatcheries, and a skewed sex ratio. It was hypothesized that a stock native to the upper Columbia River might perform better than the coastal Lake Whatcom stock. Kokanee from Meadow Creek, a tributary of Kootenay Lake, British Columbia were selected as an alternative stock. Post smolts from each stock were released from Sherman Creek Hatchery in late June 2000 and repeated in 2001. Stock performance was evaluated using three measures; (1) number of returns to Sherman Creek, the primary egg collection facility, (2) the number of returns to 86 tributaries sampled and, (3) the number of returns to the creel. In two repeated experiments, neither Meadow Creek or Lake Whatcom kokanee appeared to be capable of providing a run of three-year old spawners to sustain stocking efforts. Less than 10 three-years olds from either stock were collected during the study period. Chi-square analysis indicated age two Meadow Creek kokanee returned to Sherman Creek and to other tributaries in significantly higher numbers when compared to the Lake Whatcom stock in both 2000 and 2001. However, preliminary data from the Spokane Tribe of Indians indicated that a large number of both stocks were precocial before they were stocked. The small number of hatchery three-year olds collected indicated that the current hatchery rearing and stocking methods will continue to produce a limited jacking run largely composed of precocious males and a small number of three-year olds. No kokanee from the study were collected during standard lake wide creel surveys. Supplemental creel data, including fishing derbies, test fisheries, and angler diaries, indicated anglers harvested two-year-old hatchery kokanee a month after release. The majority of the two-year old kokanee harvested were from a direct stock at the Fort Spokane boat launch. Only Lake Whatcom kokanee were stocked from the boat launch, therefore stock performance was not evaluated, however the high success of the stocking location will likely increase harvest of hatchery kokanee in the future. Despite low numbers of the targeted three-year olds, Meadow Creek kokanee should be stocked when possible to promote fish native to the upper Columbia River.