Exploitation of Nile Tilapia in a Closed-System Public Fishing Reservoir in Northern Arkansas

Abstract

Nile tilapia Oreochromis niloticus have been stocked as a forage species annually since 2001 in Lake Hogue, a 101-ha, closed-system public fishing reservoir in northeastern Arkansas. A mail-in reward tag study was implemented in 2003 to determine total estimated harvest, contribution of Nile tilapia to the lake's fishery, and impact of angler harvest on Nile tilapia reproduction. Estimates of harvest were corrected for tag loss (1.1%), tag-induced mortality (1.0%), and nonreporting of tags by anglers (53% reporting rate). Angler-hours were compared between anglers targeting Nile tilapia and those targeting other species. Anglers harvested an estimated 83% of the stocked Nile tilapia (56% of stocked fish were captured by traditional panfishing techniques; 27% were captured by use of dip nets during the winter die-off in late November). Anglers targeting primarily Nile tilapia fished significantly longer (5.7 h/angler) than individuals who incidentally caught Nile tilapia while fishing for other species (4.5 h/angler). Analysis of the economic impact of stocking Nile tilapia demonstrated a benefit-cost ratio of 0.38. Harvest of Nile tilapia did not apparently interfere with the management goal of using the fish as a forage species for game fishes. Tag return data strongly suggested that at midday during the hot summer months, when fishing pressure had traditionally been low, anglers targeted Nile tilapia in favor of the traditional target species (e.g., bluegill Lepomis macrochirus and redear sunfish L. microlophus).