INVESTIGATOR GROUP EXPEDITION 2006: SPONGES (PORIFERA)

The diversity of marine sponges on the rocky reefs Surrounding the Investigator Group of islands in South Australia was investigated for the first time. Line intercept transects at Flinders, Pearson and Ward Islands at similar to 5 in deep, showed the algal dominance of the sub-tidal rocky reefs. Along these transects, quadrat Surveys showed low sponge occurrence Oil upward facing reefs, but in eaves and under overhangs sponges and other sessile fauna were dominant. Divers collected 71 sponge species, 10 in the Class Calcarea and 61 in the Class Demospongiae from the reefs of five islands: Flinders, Pearson, Dorothee, Ward and Topgallant. Many of the sponges had evidence of algal or cyanobacterial symbionts, possibly reflecting the clear shallow-water conditions of the sites. There was little overlap between this collection and a previous collection from the Great Australian Bight Marine Park Benthic Protection Zone, with only three sponges in common.