Distribution and Diversity of Benthic Macroinvertebrates Associated with Aquatic Macrophytes

We examined macroinvertebrate characteristics and associations with macrophytes in a small spring-fed impoundment, Aquetong Lake in Bucks County, PA. Benthic samples obtained from the 1 m depth contour were sieved to collect, identify, and determine dry mass on macroinvertebrates, detrital material, macroalgae and macrophyte tissue. Chironomids dominated along with gastropods and isopods. Chironomids were twice as abundant along the siltier nearshore bank. The sandier far shore bank supported two-fold higher taxonomic richness with macroinvertebrate mass also being 25% higher. Vascular macrophytes characterized the silty sediment, while macroalgae and allochthonous detritus predominated in sandy sediment. Results from linear and quadratic regressions suggest that macroinvertebrate mass and abundance are higher in algal-dominated sites, but higher taxonomic richness and macroinvertebrate diversity are associated with vascular macrophyte communities.