Rainbow Trout Strain Evaluation For Georgetown Lake During The Summer Of 1987

Abstract

Two newy introduced strains of rainbow trout, Eagle Lake and Kamloops rainbow, were examined to determine their sizes and populations in the angler's creel. Arlee rainbow that were present in the lake before the introduction of the new strains were examined to determine how they were being affected by the new fish and managment change. Eagle Lake rainbow decreased in average size from 13.8 in. to 12.6 in. and from 30% to 16% of the fisherman's catch compared to the winter of 1986-87. Average length of Kamloops rainbow increased by 1.3 in. from the winter of 1986-87 to 12.5 in. The percent of the fisherman's catch of this strain increased from 1% to 10%. Arlee rainbow increased in average length from 11.5 to 12.7 in. when compared to the winter of 1986-87, and from 71% to 74% of the angler's catch. Kamloops rainbow increased in both average size and population in the angler's creel. Eagle Lake rainbow increased in average size but showed a decrease in number which could not be accounted for. Eagle Lake and Kamloops rainbow were predacious on the large population of redside shiners (Richardsonius balteatus) in the lake but not on juvenile Kokanee salmon. It appears that Eagle Lake and Kamloops rainbow are reaching the size and age required for the ingestion of these smaller fish, but are not fully piscivorous yet.