Influence of river discharge on recreational harvest of paddlefish



The Neosho River at Chetopa Dam, Kansas, USA, supports a tailwater paddlefish, Polyodon spathula (Walbaum), snag fishery that is open annually to harvest from 15 March to 15 May and managed to provide anglers with maximum catch. Paddlefish inhabiting this portion of the river are presumed upstream spawning migrants from Grand Lake of the Cherokees, Oklahoma. Angler success in a paddlefish snag fishery is dependent on fish density, a factor that is likely influenced by river hydrology. However, links between river flow regime and angler harvest remain largely unquantified. In this study, hydrological factors that significantly affected paddlefish harvest were identified by regressing paddlefish harvest data from 1992 to 2005 against discharge variables. Two variables describing number of days discharge exceeded a critical threshold that allowed fish to pass a migratory barrier and frequency of discharge increases following decreases combined to explain 53% of variation in harvest. These results can be applied to promote more effective management of this population through increased understanding of relationships between hydrology and harvest. Specifically, anglers can be informed of factors leading to increased harvest in an attempt to increase satisfaction, and cooperating agencies can use these results to develop future water management plans in an effort to increase harvest.