Multiple Electrofishing Removals for Eliminating Rainbow Trout in a Small Southern Appalachian Stream

Abstract

We evaluated multiple electrofishing removals of rainbow trout Oncorhynchus mykiss as a management tool for the restoration of native brook trout Salvelinus fontinalis in a small southern Appalachian stream. Six, three-pass depletion removal efforts were conducted between Jun 1996 and Oct 1997. Four removals successfully eliminated rainbow trout reproduction. Five removals were required to successfully eliminate rainbow trout from Mannis Branch. During the study, 428 rainbow trout were removed from the treatment area. The initial removal collected 296 (70%) of the total rainbow trout removed and was dominated by adults. Subsequent removals were dominated by age-0 rainbow trout (57–83%). The initial two removals successfully eliminated 96% of the reproductively mature adults as well as 86% of the age-0 fish. In Oct 1996, 105 native southern Appalachian brook trout of various age-classes were reintroduced into Mannis Branch. Surveys conducted in May 1997 indicated adult brook trout successfully spawned, initiating repopulation of the treatment area. Multiple removals exhibited no negative population level effects on blacknose dace Rhynichthys atratulus in the treatment area or on rainbow trout in the control stream. Based upon these results, a minimum of three removals conducted per summer should eliminate reproduction and significantly reduce the number of years required to successfully restore a small southern Appalachian stream.