1. Centre for Coral Reef Biodiversity, James Cook University, Townsville, Qld 4811, Australia.
2. Environmental Protection Agency, Old Quarantine Station, Cape Pallarenda, Townsville, QLD 4810, Australia.
3. Department of Systems Ecology, Stockholm University, SE-106 91 Stockholm, Sweden.
4. Center for Population Biology, Division of Biological Sciences, Section of Evolution and Ecology, 1 Shields Avenue, University of California, Davis, CA 95616, USA.
5. Centre for Marine Studies, University of Queensland, St Lucia, QLD 4070, Australia.