Brook Trout Enhancement Through Rainbow Trout Removal by Electroshocking in the Great Smoky Mountains National Park

Brook trout ( Salvelinus fontinalis) populations have declined in the Great Smoky Mountains National Park since the early 1900\u27s. The continuing range loss of the Parks\u27 only native trout species has been attributed mainly to the introduced rainbow trout ( Salmo gairdneri ) . Past studies have indicated that removal of introduced trout by electroshocking results in the enhancement of brook trout populations. Twelve study streams in the Park were grouped as control and treatment streams. Removal efforts of one, two, and three passes consecutively were conducted on treatment streams to determine the effort needed to control rainbow trout populations. Rainbow trout were removed from these streams and released below a downstream barrier. One year after renovation efforts, the streams were again surveyed. Results of these surveys indicated that the decline of rainbow trout populations was no greater in three-removal streams than the decline in one-removal streams. Rainbow trout populations decreased in one of the two-removal streams, but increased in the other two-removal streams. This increase was attributed to the lower capture rate in these wider-than-average treatment streams. Brook trout populations increased in the one-removal and two-removal streams, but decreased in the three-removal streams. The two-removal and three-removal efforts required a 60% increase in time over the one-removal effort. The large time increase and the population results in the two-removal and three-removal streams do not warrant use of more than a one-removal effort for restoration. Restoration with one-removal efforts on a regular basis should continue in these streams and other Park streams for the recovery of the brook trout