Performance of Stocked Brown Trout Fingerlings in Selected Lanesboro Area TroutStreams. Completion Report

摘要

The performance of spring-stocked fingerling brown trout was evaluated in termsof survival and growth in three Southeastern Minnesota trout streams. Data were compared with two other, non-stocked streams. Catch statistics were derived from spring and fall electrofishing samples collected between 1992 and 1998. Stocked fingerlings survived to age IV, but in each case stocked cohorts were essentially extirpated between age III and IV. Initial overwinter mortality was consistently higher and total annual survival was lower for stocked fingerlings compared to wild stocks. Growth (mean total length at scale-age) was consistently greater for stocked fingerlings, however, recruitment to preferred sizes (greater than 12 inches TL) is questionable. Survival was linked to managers' perceptions about natural reproduction status, and a refined stocking strategy should include an evaluation of both the age-class structure of the resident trout population and life-stage specific habitat requirements.