Resource use, growth and effects of stocking in alpine brown trout, Salmo trutta L.

Abstract. Wild and stocked brown trout, Salmo trutta L., were sampled in the alpine Norwegian Lake Bjornesfjorden by standard net gangs and commercial fishery. Stocked fish comprised about 30% of the total stock. There was no significant difference in spatial distribution and diet between native and stocked fish. Both groups used the littoral zone, and Gammarus lacustris and Lepidurus arcticus were the main food items. Stocked brown trout reached a specific length one year younger than corresponding wild fish. Therefore stocked brown trout entered the commercial catch one year younger than the native fish.