Largemouth bass abundance and angler catch rates following a habitat enhancement project at Lake Kissimmee, Florida

A habitat enhancement project was conducted at Lake Kissimmee, Florida, during 1995-1996 to improve fish habitat and remove dense inshore vegetation caused by stabilized water levels. We evaluated abundance of age-1 (<250 mm total length [TL]) and adult (fish at least 356 mm TL and all sizes of fish caught by anglers) largemouth bass Micropterus salmoides before and after the habitat enhancement. Mean electrofishing catch per hour (CPH) of age-1 largemouth bass increased significantly after the 1995-1996 habitat enhancement, suggesting strong year-classes for 2 years after the habitat enhancement (i.e., 1997-1998 year-classes). Growth of age-1 largemouth bass also increased following habitat enhancement; mean total length of age-1 fish averaged 143 mm before enhancement and 186 mm after enhancement. Catch curves conducted in 2001 and 2002 corroborated historical electrofishing data indicating that the 1997 and 1998 year-classes were abundant as adults compared with other year-classes in the age frequencies. Age-1 largemouth bass electrofishing catch rates were not related to seasonal water levels or coverage of hydrilla Hydrilla verticillata. Despite the rapid growth rates and high abundance of the 1997 and 1998 year-classes, neither electrofishing catch rates of largemouth bass at least 356 rum TL nor angler catch rates of largemouth bass (fish/h, all sizes of fish, harvested or released; data from creel surveys) differed significantly between preenhancement and postenhancement periods. Thus, we were unable to detect a change in adult largemouth bass abundance or angler catch rates following the habitat enhancement. Fishing effort directed toward largemouth bass declined after enhancement for the winter period (November-February) but did not differ significantly between preenhancement and postenhancement periods for the summer (May-August) period. Benefits of muck removal concurrent with lake drawdowns include increased recreational opportunities and improved habitat. However, our results indicate that fish population responses to drawdowns and muck removals may vary and detecting effects on the adult largemouth bass populations can be difficult. Therefore, habitat enhancement efforts should focus on lakewide recreational benefits rather than benefits to a single preferred species (e.g., largemouth bass).