Patterns of abundance and size across varying spatial scales for the coral reef sponge Coscinoderma matthewsi

Spatial variability in abundance and size of sponges are poorly understood compared with other sessile organisms such as corals. A hierarchical survey design across 3 spatial scales - sites nested in locations nested in island groups - examined variation in sponge size and abundance for the common coral reef sponge Coscinoderma matthewsi (Lendenfed, 1886) (Demospongiae: Dictyoceratida) in Torres Strait, northern Australia. The abundance of C. matthewsi differed significantly across all 3 spatial scales, varying greatly between sites 200 m apart up to island groups 60 km apart. The size frequency distributions of C. matthewsi varied between sites and island groups, and were positively skewed with populations dominated by small sponges. There was no relationship between sponge abundance and size within and between island groups for C. matthewsi in Torres Strait.