Tennessee Wildlife Resources Agency

TWRA's Region 4 - East Tennessee

Reservoir Fisheries Management Program

TWRA Electrofishing Surveys


The TWRA conducts shoreline electrofishing surveys on most East Tennessee reservoirs every year.  Electrofishing or "shocking" is one of the most effective and efficient methods of collecting quality samples of crappie, walleye, musky and bass.

This sampling procedure is used to provide information about the growth, mortality, recruitment and abundance of fish populations.  It is usually conducted in the spring when species have moved into shallow water in preparation for spawning.  Hatchery personnel also use electrofishing during various times of the year to collect brood fish for tank spawning.

Boats equipped with generators, probes and "pulsators" are maneuvered slowly along the shoreline. Pulsators convert the generator's AC current to DC current which causes minimum stress to the fish. Fish that are temporarily stunned by the electrical field that extends 10 to 20-feet around the boat are captured in a dip net and transferred to live wells equipped with aerators. They completely recover within a few minutes and rarely exhibit signs of stress or injury.

Each collection period lasts 900-seconds and anywhere from 15 to 40 samples are taken throughout each reservoir. Sampling effort is equally allocated to the most abundant habitat types. Fish are quickly weighed, measured and checked for parasites and abnormalities. They are then released as close as possible to the area from where they were captured.


Electrofishing Survey Results:

Davy Crockett
John Sevier
Norris Melton Hill Fort Loudoun Tellico Douglas Cherokee Fort Patrick Henry Watauga Boone South Holston John Sevier Davy Crockett Wilbur Chilhowee Calderwood


Electrofishing Demonstration Video


Electrofishing Boat