Effects of a minimum length limit on saugeye population and fishery characteristics in Ohio reservoirs

Objective We evaluated the effect of a 381‐mm minimum length limit (MLL) on saugeye (female Walleye Sander vitreus × male Sauger S. canadensis) population and fishery characteristics implemented in Ohio reservoirs in 2011. Methods Using a before‐after–control‐impact study design (n = 6 control populations and n = 11 impact populations that received the MLL), we compared total CPUE, age‐2+ CPUE, proportional stock density‐harvestable (381‐mm), and length at age 2 (to index growth) determined from standardized gill‐net surveys and saugeye angler effort, catch rate, harvest rate, length of saugeye at harvest, yield, and satisfaction obtained from standardized creel surveys. Result We found evidence that the 381‐mm MLL led to an increase in age‐2+ CPUE but had no effect on other saugeye population metrics. In the regulation reservoirs, harvest rates declined following MLL implementation. Total length of harvested saugeye did not increase significantly in response to the MLL, and combined with decreased harvest rates, yield was suppressed in the regulation reservoirs relative to the control reservoirs. However, over 90% of anglers reported that they were satisfied with the MLL during creel surveys. Conclusion Despite marginal influence on saugeye populations and failure to increase yield, anglers supported the MLL. Our results suggest that the effects of harvest regulations may be marginal, and managers should consider the nuances of angler satisfaction in regulation decisions. Impact statement Fisheries management agencies commonly use minimum length limits to attempt to improve recreational fisheries; however, robust evaluations of regulation success are often lacking. In saugeye fisheries, minimum length limits minimally affected population size structure and angler yield but still received strong angler support. Fisheries managers should implement rigorous experimental designs in regulation evaluations and consider both biological and social effects of fishery regulations.