Effects of conservation practices on fisheries management

Beasley Lake watershed located in the Mississippi River Alluvial Plain was subjected to a series of conservation management practices with the goal of reducing sediment and nutrients entering the lake via agricultural runoff. Concurrent with the application of conservation practices, the lake was renovated and restocked to produce a sports fishery. Conservation practices reduced annual mean total solids from 592 mg/L in 1996 to 66.7 mg/L in 2011 resulting in increased Secchi visibility from an annual mean of 16 cm to 28 cm. Phosphorus was reduced by 95% from 1.75 mg/L to 0.08 mg/L while nitrate was reduced by 58% from an average annual high of 0.69 mg/L in 1996 to 0.29 mg/L in 2011. Recovery of the fishery following restocking was slow until after 2000 when water quality improved. Numbers of fish per unit of effort peaked at 82 / hr. in 2006 while highest combined catch per unit of effort (9.37 kg/h) was reported in 2009. While clupeids and centrarchids were an important component of the catch by number for the duration of the study, there was a shift from a carp-catfish dominated catch in 1998 – 1999 to one dominated by centrarchids and clupeids by 2004. Catch and numbers per unit of effort over time show a cyclic pattern of highs and lows indicating instability within the fish community. The decision not to harvest fish in favor of catch and release and the reduction of nutrient concentrations within the lake likely contributed to reduced catch per effort in 2011.