Macrobenthic Community Structure in a Transplanted Eelgrass (Zostera marina) Meadow

Abstract

203-d survey of eelgrass macrofauna was conducted in an experimental eelgrass transplant which developed different degrees of macrophyte cover. This is the first study of a benthic macrofaunal community in a transplanted seagrass meadow; it demonstrates the effect of seagrass on macrofaunal density, species abundance, diversity, and dominance. Species composition and numerical dominants varied with season during the experiment, with decreasing affinities between the fauna of the developing seagrass meadow and the unvegetated controls. Various polychaete species were the numerical dominants throughout the experiment. Both time and density of eelgrass significantly affected the 4 community parameters measured. Species composition, numerical abundance, number of species, species diversity, and dominance were similar among all treatment and control plots before transplanting eelgrass. These parameters increased linearly in the unvegetated control plots from October 1978 to May 1979. Macrofaunal density. number of species and diversity responded positively but non-linearly to increasing eelgrass shoot density in the developing meadow Dominance decreased nonlinearly with increased shoot density. Shoot density appeared to be a major factor regulating the structure of the developing eelgrass community