Clancy, N.G., J. Dunnigan, and P. Budy. 2022. Relationship of trout growth to frequent electrofishing and diet collection in a headwater stream. North American Journal of Fisheries Management, Management Brief 42:109–114. DOI: 10.1002/nafm.10728. USGS FSP IP-133486.
Abstract
Research on fishes sometimes requires that individual fish be captured and subjected to invasive procedures multiple times over a relatively short time span. Electrofishing is one of the most common techniques used to capture fish and is known to cause injury to fish under certain circumstances. We evaluated the relationship of Columbia River Redband Trout Oncorhynchus mykiss gairdneri growth rates to the number of times captured via electrofishing and gastrically-lavaged during the summer of 2018 in a mountainous, headwater stream. We captured fish between two and seven times over the course of 86 days using continuous (smooth) DC backpack electrofishing. We observed no relationship between Redband Trout growth rate and number of times captured or gastrically-lavaged. While these findings contrast with hatchery electrofishing experiments, they may represent the greater resiliency of wild fishes. However, it appears researchers can use electrofishing and gastric lavage in cold waters at least once-per-month, and potentially up to twice-per-month, without greatly affecting the growth of wild Redband Trout.