1. Marine Geospatial Ecology Lab, Nicholas School of the Environment, Duke University, Durham, NC 27708, USA.
2. Nippon Foundation Nereus Program and Changing Ocean Research Unit, Institute for the Oceans and Fisheries, The University of British Columbia, Vancouver, British Columbia, Canada.
3. Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada.
4. United Nations Environment Programme World Conservation Monitoring Centre, 219 Huntingdon Road, Cambridge CB3 0DL, UK.