Nearshore benthic community structure at the Bounty and Antipodes Islands, Subantarctic New Zealand

Management decisions aimed at protecting biodiversity ideally should be based on biological information, but for remote and logistically difficult sites, such as are found at high latitudes, these data may be lacking. During March 2009, surveys were completed of the nearshore rocky reef communities around the Bounty and Antipodes Islands, in New Zealand??s subantarctic region. Previously considered to support the same habitat types (which used physical variables as surrogates for biological communities), analysis of photoquadrats taken at both island groups showed that the rocky reef communities were significantly different, both in terms of their species composition and in terms of their potential ecological function. While Antipodes Island supported fairly typical subantarctic shallow subtidal marine communities dominated by nongeniculate coralline algae, the rocky reefs at the Bounty Islands were dominated by filter- and suspension-feeding invertebrates, in particular encrusting sponges, barnacles and mussels. The mobile invertebrate fauna associated with these communities were also significantly different between the two island groups. Contrasting geology, oceanographic conditions and nutrient input from seabird and pinniped colonies may all contribute to the observed nearshore community structures at the Bounty and Antipodes Islands. Our research provides a baseline for assessing change in the subantarctic region and highlights the importance of using biological community data where available, to inform conservation management decisions.