By Kevin Tate/Outdoors Writer
The overall health of the Tennessee River system of reservoirs is safe and sound – so says data gathered by teams of fisheries biologists whose work turns hopeful opinion into documented fact.
Operating gear designed to temporarily stun but not permanently harm fish with the use of an electric current in water, teams of TVA biologists spend roughly 25 weeks in the spring and fall collecting data on the fish that live in the 31 reservoir lakes along the length of the Tennessee River. The fish are measured, weighed, inspected for injury or ailment and then released in the area from which they were collected.
“TVA has been collecting data of one sort or another on these lakes since the 1930s, but this particular electrofishing survey has been underway since 1994,” John Justice, TVA fisheries biologist, said. Justice is a field team member and part of the literal hands-on gathering of the data used by the agency to guide the stewardship of the resource. The data is also made available to state wildlife agencies to assist with their management of the fisheries. Furthermore, the data is also available to the public free of charge and is includes an indexed rating by lake and species.
The spring index focuses on fish at the top of the food chain. By studying largemouth, smallmouth and spotted bass, black and white crappie, walleye and sauger, fish whose diet consists of other fish, the biologists are able to track the overall health of a given habitat. If the fish at the top are healthy and thriving, it can only be because every element of the food chain below is strong as well.
In any given reservoir, the scientists sample a balanced selection of good, fair and poor habitat, and they make their samples at approximately the same time every year, and in the same habitat locations. This allows for a consistent track of the overall lake system and the aquatic ecosystem at large.
“We want to see a good distribution of lengths of fish, a good weight per length ratio and a good catch rate,” Justice said. The results so far this spring, he added, are looking very strong, indicating the river system’s managers and Mother Nature are on the right track.
To view data for specific lakes, visit www.tva.gov and search “spring sportfish survey.”
Selected spring survey runs are open to the public free of charge. To ride along in an electrofishing boat, call 800-882-5263 for schedules and openings. You’ll need to bring your own lifejacket, drinks, snacks and sunscreen.