9781934874127-ch15

Paddlefish Management, Propagation, and Conservation in the 21st Century

Joint Management of an Interjurisdictional Paddlefish Snag Fishery in the Missouri River below Gavins Point Dam, South Dakota and Nebraska

Gerald Mestl and Jason Sorensen

doi: https://doi.org/10.47886/9781934874127.ch15

Abstract.—The paddlefish Polyodon spathula snag fishery, jointly managed by the Nebraska Game and Parks Commission and the South Dakota Department of Game, Fish and Parks, on the Missouri River from Gavins Point Dam near Yankton, South Dakota (river mile [rm] 811 [river kilometer {rkm} 1,305]) to the mouth of the Big Sioux River near Sioux City, Iowa (rm 734) has undergone many changes over the past 50 years. Changes in season length and harvest regulations were aimed at reducing overall paddlefish harvest and altering the population structure. This snagging season has evolved from an open, year-round fishery with liberal daily and possession limits to a 30-d limited-entry season with a conservative number of harvest tags issued by lottery drawing in 1997. Angler interest continues to increase as indicated by the increasing number of applicants for harvest tags. There was no difference in total fishing use or mean hours snagged per angler; however, South Dakota anglers were more likely to fish weekdays and in the Gavins Point Dam tailwater than Nebraska anglers. No differences were found between the number of fish harvested or the harvest rate among Nebraska and South Dakota anglers from 1997 through 2006. Total harvest, harvest rates and the number of paddlefish caught and released dramatically increased in 2004–2006. Response of the paddlefish population to regulation changes has been positive. There has been a significant increase in mean length of paddlefish sampled with nets from 1991 to 2005 (r2 = 0.73), and significant increases in both proportional stock density (r2= 0.78) and relative stock density of preferred length fish (r2 = 0.57) from 1982 to 2005. The success of joint management of this interjurisdictional paddlefish snag fishery was the result of angler input, population and harvest monitoring, mutual regulation changes, and cooperation from both state agencies.