Angling and Electrofishing for Removing Nonnative Rainbow Trout from a Stream in a National Park

Abstract

An experimental 9-week fishery was conducted in a Great Smoky Mountains National Park stream (Lynn Camp Prong) to evaluate the use of angling and electro fishing as techniques for reducing the density of a non-native rainbow trout (Salmo gairdneri) population. Most anglers were local residents in Tennessee. Angler visits were highest during the first 2 weeks and declined steadily thereafter. Anglers harvested 5,655 rainbow trout whose total lengths fell within the 80-and 280-mm size classes. The electrofishing crew caught fish in length classes between 30 and 280 mm. The adjusted preseason electrofishing catch per unit effort (CPUE) was 3.71 fish/h based on the time taken for daily preparation, travel, and electrofishing. When based on electrofishing time only, the CPUE was 5.90. The CPUE for one clerk at a creel station was projected to be substantially greater (6.70) than that for the electrofishing crew. In addition, total costs were far greater for the electrofishing crew because of equipment, travel, materials and supplies. A smaller crew could have been used but, based on comparative CPUE data from electrofishing efforts on smaller park streams, the simultaneous use of four backpack electrofishing units abreast across the stream plus four people netting and carrying water buckets and two people processing the catch was about optimal for the size of the stream (average width of 11.46 m). Our results suggest, therefore, that experimental fishing programs offer a cost-effective, alternative method for reducing densities of non-native rainbow trout in large park streams.