Abstract
Assessment of the extent of coral bleaching has become an important part of studies that aim to understand the condition of coral reefs. In this study a reference card that uses differences in coral colour was developed as an inexpensive, rapid and non-invasive method for the assessment of bleaching. The card uses a 6 point brightness/saturation scale within four colour hues to record changes in bleaching state. Changes on the scale of 2 units or more reflect a change in symbiont density and chlorophyll a content, and therefore the bleaching state of the coral. When used by non-specialist observers in the field (here on an intertidal reef flat), there was an inter-observer error of ± 1 colour score. This technique improves on existing subjective assessment of bleaching state by visual observation and offers the potential for rapid, wide-area assessment of changing coral condition.
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Acknowledgments
We thank Kylie Jennings, Kylie McPherson, Collette Bagnato, David Logan, Craig Reid, Maria del Carmen Gomez Cabrera, the staff of the Heron Island and Lizard Island Research Stations, and Ian Osborn, the ranger on Green Island, for help and advice during this work. We thank the editors of Coral Reefs for their constructive comments and discussion. This project was supported by the Sustainable Tourism CRC, the Australian Research Council, The University of Queensland Vice Chancellor’s Strategic initiative fund and the Global Environmental Facility Coral Reef Targeted Research project (http://www.gefcoral.org). The project was also generously sponsored by P&O, Daikyo, Voyages Resorts and The Marine Teachers Association of Queensland. We are grateful to the following organisations for help in distributing coral cards worldwide: Project Aware - PADI, Reef Check, GLOBE, NOAA.
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Communicated by Ecology Editor P.J. Mumby
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Siebeck, U.E., Marshall, N.J., Klüter, A. et al. Monitoring coral bleaching using a colour reference card. Coral Reefs 25, 453–460 (2006). https://doi.org/10.1007/s00338-006-0123-8
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DOI: https://doi.org/10.1007/s00338-006-0123-8