Changes in sport fish characteristics and biomass of aquatic vegetation before and after biological control of vegetation in southern Arkansas

Felsenthal National Wildlife Refuge has developed an aquatic vegetation problem that hinders angler access and has reduced public visits.  Largemouth bass and bluegill were sampled using boat electrofishing.  Twenty-meter transects and 1-m2 quadrats were used to determine vegetation cover and biomass.  Twenty-five centimeter grass carp were stocked at a rate of 6.5 fish/ha.  Fish and vegetation sampling was repeated following stocking.  Pre-stocking mean (SD) CPUE of largemouth bass was 15 (9) fish/hr and mean bluegill CPUE was 61 (68) fish/hr.  Post stocking mean (SD) CPUE of largemouth bass was 45 (35) fish/hr and mean CPUE of bluegill was 144 (157) fish/hr.  Post stocking relative abundance for largemouth bass and bluegill changed significantly.  Bluegill SL significantly changed post stocking.  Length at age significantly changed for bluegill age classes 1 – 4 and largemouth bass age classes 1 -3.  Bluegill 2008 and 2009 mortality was 0.76 and 0.84.  Largemouth bass 2008 and 2009 mortality was 0.70 and 0.6.  Mean percent cover was 19 (35)% and mean biomass was 93 (232) kg/m2.  The most abundant aquatic vegetation species were American Lotus, Hydrilla, and Coontail.  Fish and vegetation assessments will continue to examine changes in plant and fish communities during biological control of vegetation.