The Effects of Industrial Pollution on the Development and Succession of Marine Fouling Communities I. Analysis of Species Richness and Frequency Data

Abstract. The effects of industrial pollution were determined by comparing the pattern of development of marine fouling communities situated along a pollution gradient within Port Kembla Harbour (Australia) with those from nearby Wollongong Harbour, a relatively unpolluted area. Fifty-three fouling species were found in the communities from Wollongong Harbour compared to only 40 in those from Port Kembla Harbour. Twenty-eight species (including many bryozoans) occurred only in the former, while 15 species occurred solely in the latter. Ten of the 25 species common to both areas were more numerous in Port Kembla Harbour, probably because of the greater availability of free substratum and food in this area. The species richness of fouling communities in Port Kembla Harbour was found to decrease as pollutant concentrations increased. In both study areas, communities established in summer showed significantly higher species richness than those whose development was initiated in winter. This difference was less pronounced in Port Kembla Harbour and was attributed to the effects of pollution on larval settlement. Although species richness increased at all sites through time, Wollongong Harbour communities contained a greater number of species at the end of the experiment than communities from Port Kembla Harbour. Despite this, fewer species were found in the very early developmental stages of the communities from Wollongong Harbour. This result highlights the inherent problems associated with using species richness or diversity measures as a means of determining marine environmental quality.