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

Shad scoop in front of boat, block-off net behind boat


This technique is most commonly used to sample fish populations in reservoirs. Because one of the main purposes of cove-rotenone sampling is to evaluate reproductive success of sportfish and their forage, it is usually conducted in late summer. A cove is selected, then blocked ff by a net that extends from surface to bottom. This keeps fish from entering or leaving the sample area. Rotenone, a fish toxicant, is introduced into the cove at a rate suffcient to kill only the fish in the sample area. Rotenone interferes with the way fish breath. They are dipped up when they surface or when they drift up after dying. The pick-up lasts two days to make sure all the fish are recovered. The fish are then sorted out by species, sized,and weighed. By this method, we obtain the widest range of data about cove fish populatiuons in the reservoir. In our area, we conduct rotenone samples on three coves on both Bull Shoals and Norfork Lakes. We do this annually and have 20 to 30 consective years of rotenone data. This database is used to evaluate the effects of fisheries management actions and environmental influences.

Results of cove sampling: Counted, sized, identified