Competitive strategies in soft corals (Coelenterata, Octocorallia). 4. Environmentally induced reversals in competitive superiority

Long-term evidence has demonstrated that an inshore reef (Pandora Reef) in the central region of the Great Barrier Reef, Australia, is becoming increasingly dominated by octocorals. To examine the effects of the local environmental setting on the outcome of competition for space, pairs of octocoral and scleractinian corals actively competing for space were transplanted from this inshore reef to a mid-shelf one (Britomart) in a controlled experiment. The 2 areas differ in their physical characteristics and biological communities. Competition for space between Clavularia inflata, Briareum stechei , and Acropora longicyathus in all possible pairs was assessed. Controls included undisturbed paired and solo colonies in their natural environment. A second set of corals was relocated to the mid-shelf and returned to its original environment as a control for handling effects. Competitive advantage was estimated via growth rate.