The influence of littoral zone structural complexity on fish assemblages in Lake Conroe, TX

Abstract

The littoral zone of an East Texas reservoir was surveyed to determine if any characteristic fish assemblages were associated with four different habitat types with varying levels of structural complexity. A stratified random sampling design was used to select four sampling sites each from vegetated, understated, rip-rapped and bulkheaded shorelines. Each site was sampled seasonally for one year. Sites were surrounded by a block net and electrofished exhaustively. Seasonal and spatial differences in biomass, abundance, species richness and diversity were detected. Biomass and abundance were highest in spring, lowest in winter and intermediate in summer and fall. Species richness was lower in winter than in all other seasons, and diversity did not vary among seasons. Biomass was higher in rip-rapped habitat than in bulkhead and unvegetated habitat, but not higher than in vegetated habitat. Biomass was higher in both vegetated and bulkheaded habitat than in unvegetated habitat. Abundance did not vary across habitats. Species richness and diversity were higher in rip-rapped and vegetated habitat than in unvegetated and bulkheaded habitat. characteristic assemblages were identified among the four habitat types using multivariate ordination techniques. These results can be used to develop management strategies related to shoreline development projects and their effects on fish habitat.