AN ANALYSIS OF BENTHIC MARINE INVERTEBRATE COMMUNITIES IN SUBTIDAL SEAGRASS AND SAND HABITATS IN SHARK BAY, WESTERN AUSTRALIA

WA Museum Records and Supplements | Updated 1 decade ago

Abstract: The fauna of three habitats (Posidonia and Amphibolis seagrass beds and open sand) on a subtidal sandflat off Monkey Mia, Shark Bay, Western Australia (25 0 48'S, 113°43'E), was investigated. The fauna of the seagrass beds was diverse and abundant. Amphibolis stations had 115 species, a total density of 332.2 individuals/ m2 and a shellfree, dry biomass of 32.5g/m2. The corresponding figures for Posidonia stations were not significantly different: 97 species, 298.1 individuals/m2 and 38.0g/m2. By comparison the sand stations were impoverished: 20 species, 19.3 individuals/m2, and 4.3g/m2. There was a substantial overlap of species between the two seagrass habitats but little overlap between the fauna of either seagrass and sand stations. Epifauna and epibiota dominated the seagrass stations. Infauna was relatively rare, but at the same level as in the sand stations, where it was dominant. Reasons for the relative impoverishment of sand stations are discussed.