Ecological and conservation significance of the subtidal rocky reef communities of northern New South Wales, Australia

Abstract

The subtropical rocky reefs of Cook Island, Julian Rocks and the South West Rocks area form part of a chain of islands and reefs with significant coral cover from the Queensland border (28˚S) to the southern extent of extensive coral communities in coastal Australia (31˚S). Benthic communities at 18 subtidal sites at the three localities were surveyed quantitatively by video-transects, and coral species lists were compiled. Twenty-eight coral species previously unrecorded for these localities were identified, increasing the species richness of hermatypic corals reported for the northern NSW region (excluding the Solitary Islands) from 14 to 43. Coral species richness declined with latitude. Benthic communities were generally dominated by turfing and macroalgal species, with Pyura, sponges, and barnacles locally abundant. Scleractinian coral cover ranged from 0% to 42.6% per site, with highest coral cover at the most southern site. Julian Rocks is a designated Aquatic Reserve, and Marine Parks have been suggested for all three localities. Selection of Marine Protected Areas requires information on their ecological significance. These surveys report the first quantitative information on the shallow- water, rocky-reef communities in the region, which is a vital step in assessing their ecological significance.