Does the eelgrass meadow influence the macrobenthic community structure in Swan Lake, Northern China?

Abstract

Seagrass beds provide habitat for a wide array of organisms. Among these, macrobenthos constitute a major group in seagrass bed communities. The effects of seagrass meadows on macrobenthic community structure have been studied in many areas, and have revealed contradictory results regarding the meadow’s effects. In this study, sediment environment and macrobenthic community structure and diversity were investigated in an eelgrass bed and an adjacent unvegetated area in Swan Lake, northern China, from November 2011 to October 2012. Sediment grain size and organic matter did not differ significantly between the two areas. Polychaeta were the most abundant taxon, and herbivores, detritivores, and deposit feeders were the main functional feeding groups. Carnivores were slightly more abundant in the eelgrass bed than in the unvegetated area. Permutational multivariate analysis of variance (PERMANOVA) indicated that the macrobenthic assemblage differed between the two habitats, but analysis of similarities (ANOSIM) did not validate this result. Analysis of similarity percentages (SIMPER) demonstrated that Polychaeta was the largest contributor to dissimilarity between the macrobenthic assemblages; however, diversity was similar throughout the year, and theoretical species richness was equivalent (80 species) between the two areas. Thus, the presence of eelgrass did not affect macrobenthic community structure or diversity in the Swan Lake ecosystem.