Coral communities of the Gneering Shoals and Mudjimba Island, south-eastern Queensland

Abstract

The Gneering Shoals and Mudjimba Island are coastal rocky-reef communities approximately 250 km south of the Great Barrier Reef. Ten sites from 700 m to 12 km offshore were investigated with the use of video-transects to determine percentage cover of benthic organisms. The marine benthic communities were dominated by hard corals, soft corals and turf algae. Three community types were identified: (1) offshore communities, (2) island-associated communities, and (3) a nearshore algae-dominated community. Inshore sites were dominated by flat encrusting hard corals, whereas offshore sites were dominated by foliose and plating hard corals, particularly Acropora solitaryensis and Turbinaria spp. There was a notable scarcity of branching species, particularly from the Family Acroporidae. Seventy-seven species of scleractinian coral, representing 30 genera in 11 families, have been recorded from the Gneering Shoals region. The Gneering Shoals had low coral species richness relative to the southern Great Barrier Reef (244 species) and Flinders Reef, 50 km to the south-east (118 species). Possible explanations for the relatively low coral species richness in the Gneering Shoals region include the physical attributes of the site and the hypothesized failure of the East Australian Current to be a major influence on the region.