Patterns in marine community assemblages on continental margins: a faunal and floral synthesis from northern Western Australian atolls

Corals and fishes are the most visually apparent fauna on coral reefs and the most often monitored groups to detect change. In comparison, data on noncoral benthic invertebrates and marine plants is sparse. Whether patterns in diversity and distribution for other taxonomic groups align with those detected in corals and fishes is largely unknown. Four shelf-edge atolls in the Kimberley region of Western Australia were surveyed for marine plants, sponges, scleractinian corals, crustaceans, molluscs, echinoderms and fishes in 2006, with a consequent 1521 species reported. Here, we provide the first community level assessment of the biodiversity of these atolls based on these taxonomic groups. Four habitats were surveyed and each was found to have a characteristic community assemblage. Different species assemblages were found among atolls and within each habitat, particularly in the lagoon and reef flat environments. In some habitats we found the common taxa groups (fishes and corals) provide adequate information for community assemblages, but in other cases, for example in the intertidal reef flats, these commonly targeted groups are far less useful in reflecting overall community patterns.