Lake Norfork-Bull Shoals Lake-White River-North Fork River-Buffalo River-Crooked Creek



Biologist electrofishing Crooked Creek

Electrofishing

Electrofishing is one of the most important fish sampling tools available to biologists. The technique involves generating either a DC or an AC electric current (either with a gasoline-powered generator, or batteries) through various styles of electrodes into the water to create an electric field. Fish that pass through the field are stunned, then collected by dipnet. We use electrofishing in both lakes and streams to sample species of interest (usually sportfish). For instance, black bass concentrate along the shoreline in shallow water during the spawning season in Spring and are especially vulnerable to electrofishing during that time of year. Most of our black bass regulations are based on data collected by this techique. In streams (especially shallow ones), electrofishing is commonly used to collect estimates of fish populations. We also use the fish collected in this manner in a number of ways: to analyze the size structure of a population, to obtain growth and condition data, for marking for other studies, to determine relative abundance, etc. Data from the sampling helps evaluate the need and/or success of regulations. Electrofishing is also used to collect broodstock. Because our waters are in the middle range for conductivity, electrofishing is very effective. Very high or low conductivities limit the usefulness of this tool.


Brook trout on data board collected during electrofishing