Brown Trout Population Response to Trophy Regulations in a Southeastern U.S. Tailwater and Related Effects of Dam Discharge

The objective of this study was to evaluate the effectiveness of a 508-mm minimum length limit and a one-fish-per-day creel limit on improving the size structure of the brown trout (Salmo trutta) population in the Cumberland River below Lake Cumberland, Kentucky.  The purpose of the new regulations was to increase the numbers of quality (381-507 mm total length [TL]) and trophy-size (≥ 508 mm TL) brown trout in the tailwater.  When sample sites were combined, a significant increase in brown trout catch per unit effort (CPUE) was observed across years for small (< 381 mm), quality and trophy-size trout.  As brown trout catch rates increased over time, no corresponding decrease in growth or condition was observed.  However, growth and condition of brown trout in the tailwater were inversely correlated with an index of discharge from Wolf Creek Dam.  The trophy regulations, which did not include gear or bait restrictions, resulted in an increase in abundance and larger sizes of brown trout in the tailwater without any observed negative density-dependent impacts.