1991-2001 Evaluation of finglering walleye stocking among interior Iowa rivers Statewide angler surveys have shown interior rivers and streams are the most utilized fishery in Iowa, the result of abundance and accessibility. The surveys also indicated walleye are one of our anglers most preferred gamefish. Earlier studies determined small fingerling walleyes, stocked in late spring, significantly improved walleye populations and angling in the Cedar, Wapsipinicon and Shell Rock Rivers. As a result, fingerling stocking is now the primary management tool used to improve interior river walleye fishing. This study was designed to provide information needed to further evaluate and refine our interior river walleye stocking program. These studies have proven hatchery-reared fingerlings can vastly increase the density of fast growing walleyes in Iowa’s interior rivers. Although survival and recruitment varied from year to year, we documented populations of up to 807 walleye per mile on the Cedar River and 489 per mile on the Wapsipinicon River. Genetic strain of stocked walleye had a significant impact on survival and recruitment. Four years of side-by-side comparisons showed the Mississippi River strain fingerlings were better adapted than Spirit Lake strain fish for survival in Northeast Iowa’s interior rivers. Investigation of stocking densities at four sites on the Wapsipinicon River showed a significant relationship between the number of fingerlings stocked and the abundance of walleye fingerlings in fall samples. Based on this study, we concluded a stocking density of 425 fingerlings per mile provided the highest density of fall fingerling walleye in that river. Our results also indicated high summer discharges negatively impacted survival of stocked fingerling walleye. Mean summer discharges 3 or more times the long-term average eliminated any benefits of fingerling stocking. The introduction of fingerling walleyes in tributary streams did not offset the negative impacts of high summer discharge associated with mainstem rivers. Our five-year comparison concluded the contribution of fingerling walleyes stocked in tributary streams was less than expected relative to survival of those stocked in mainstem rivers. The walleye fingerling stocking program has been extremely popular among river anglers. Results of our creel surveys showed improvements noted in the Cedar River walleye population resulted in a five-fold increase in angler use and number of anglers targeting walleyes. Angler surveys also documented the significant contribution of stocked fingerling walleyes to the sport-fishery. Collectively, information gained from our study has helped managers meet river anglers’ demand for quality walleye fishing.
Discussion
Comments are closed.