Conclusions

The unusually warm water experienced over the summer of 2001/2002 has lead to a mass-bleaching event on the GBR. This is the second mass-bleaching event to affect the GBR in five years. While most reefs have escaped without extensive death of corals, the extent of bleaching indicates that the majority of reefs within the GBRMP were exposed to stressful conditions. The potential for bleaching to cause severe ecological damage to entire coral reef ecosystems was seen during the 1998 bleaching event at several locations worldwide, including the Maldives, Tanzania and Sri Lanka. In both recent bleaching events (1998 and 2002), the GBR has been fortunate to escape with extensive mortality of corals seen at only a few inshore reefs. The spatial extent of bleaching this year, combined with the mass death of corals seen at the worst affected reefs, provides a vivid warning of the potential for widespread and severe ecological damage should warm water events increase in severity, duration or frequency in the future.

References/Further reading:

1.      Berkelmans R. and Oliver J.K. (1999) Large-scale bleaching of corals on the Great Barrier Reef. Coral Reefs 18:55-60.

2.      Glynn P.W. (1993) Coral reef bleaching: ecological perspectives. Coral Reefs 12:1-17.

3.      Kushmaro A., Rosenberg E., Fine M., and Loya Y. (1997) Bleaching of the coral Oculina patagonica by Vibrio AK-1. Marine Ecology Progress Series 147:159-165.

4.      Mascarelli P.E. and Bunkley-Williams L. (1999) An experimental field evaluation of healing in damaged, unbleached and artificially bleached star coral, Montastrea annularis. Bulletin of Marine Science 65(2): 577-586.

5.      Michalek-Wagner K, Willis BL (2000) Impacts of bleaching on the soft coral Lobophytum compactum. I. Fecundity, fertilization and offspring viability. Coral Reefs 19: 231-239.

6.      Hoegh-Guldberg O. (1999) Climate change, coral bleaching and the future of the world’s coral reefs. Marine and Freshwater Research 50: 839-866.

7.      Brown B.E., Dunne R.P., Warner M.E., Ambarsari I., Fitt W.K., Gibb S.W., and Cummings D.G. (2000) Damage and recovery of photosystem II during a manipulative field experiment on solar bleaching in the coral Goniastrea aspera. Marine Ecology Progress Series 195: 117-124.

8.      Fisk D., and Done T. (1985) Taxonomic and bathymetric patterns of bleaching in corals, Myrmidon Reef (Queensland). Proceedings of the 5th International Coral Reef Congress, Tahiti, vol 6: pp 149154.

9.      Marshall  P.A. and Baird A.H. (2000) Bleaching of corals in the Central Great Barrier Reef: variation in assemblage response and taxa susceptibilities. Coral Reefs 19(2): 155-163.

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