Biodiversity & Conservation

, Volume 13, Issue 6, pp 1175–1194

Taxonomic patterns of bleaching within a South African coral assemblage

  • C.D. Floros
  • M.J. Samways
  • B. Armstrong


In 1998, the Indian Ocean coral reefs suffered a severe and extensive mass bleaching event. The thermal tolerances of corals were exceeded and their photosynthetic symbionts (zooxanthellae) lost. Mortalities of up to 90% were recorded on the reefs of Seychelles, Maldives, Kenya and Tanzania. South African coral reefs were among the few that largely escaped the 1998 mass bleaching event, but may be threatened in the future if global warming increases. This study assessed the extent of coral bleaching and partial recovery at Sodwana Bay, South Africa during 2000 and 2001. Bleaching levels in this study varied over the course of a year, which suggested that seasonally varying parameters such as sea temperature were the most likely cause of bleaching. Bleaching levels were highest at the shallowest site. However, these bleaching levels were very low in comparison with those of reefs elsewhere in the Indian Ocean. The greater volume of water over the relatively deeper reefs of Sodwana Bay may have protected the reefs from severe bleaching. Field measurements on the three reefs indicated that, although the reefs at Sodwana Bay are still healthy, bleaching increased from <1% in 1998 to 5–10% in 2002. Bleaching occurred in 26 coral genera. The Alcyonacea were highly susceptible to bleaching, especially Sarcophyton sp. Among the hard corals, Montipora spp. were the species most susceptible to bleaching. The sensitivity of these genera to early and slight increases in temperature suggests that they can forewarn of a possible greater bleaching event. In contrast, the coral genera Turbinaria and Stylophora were most resistant to bleaching.

Bleaching Corals Genera South Africa Taxonomic patterns 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Arceo H.O., Quibilan M.C., Alino P.M., Lim G. and Licuanan Y. 2001. Coral bleaching in Phillippine reefs: coincident evidences with mesoscale thermal anomalies. Bulletin of Marine Science 69: 579-593.Google Scholar
  2. Bouwer M. 2000. Sodwana Bay Dive Report, KwaZulu-Natal Wildlife, Pietermaritzburg, South Africa.Google Scholar
  3. Brown B.E. 1997. Coral bleaching: causes and consequences. Proceedings of the 8th International Coral Reef Symposium 1: 65-74.Google Scholar
  4. Brown B.E. and Ogden J.C. 1993. Coral bleaching. Scientific American 268: 64-70.Google Scholar
  5. Brown B.E. and Suharsono 1990. Damage and recovery of coral reefs affected by El Niño related seawater warming in the Thousand Islands, Indonesia. Coral Reefs 8: 163-170.Google Scholar
  6. Coles S.L. 2001. Coral bleaching: what do we know and what can we do? In: Salm R.V. and Coles S.L. (eds) Coral Bleaching and Marine Protected Areas. Proceedings of the Workshop on Mitigating Coral Bleaching Impact through MPA Design, Bishop Museum, Honolulu, Hawaii, May 2001. Asia Pacific Coastal Marine Program Report 0102, The Nature Conservancy, Honolulu, Hawaii, 118 pp.Google Scholar
  7. Coles S.L., Jokiel P.L. and Lewis C.R. 1976. Thermal tolerance in tropical versus subtropical pacific coral reefs. Pacific Science 30: 159-166.Google Scholar
  8. Demarcq H. and Citeau J. 1995. Sea surface temperature retrieval in tropical area with METEOSAT: the case of the Senegalese coastal upwelling. International Journal of Remote Sensing 16: 1371-1395.Google Scholar
  9. Frisk D.A. and Done T.J. 1985. Taxonomic and bathymetric patterns of bleaching in corals, Myrmidoon Reef (Queensland). Proceedings of 5th International Coral Reef Congress, Tahiti 6: 149-154.Google Scholar
  10. Gleason M.G. 1993. Effects of disturbance on coral communities: bleaching in Moorea, French Polynesia. Coral Reefs 12: 193-201.Google Scholar
  11. Glynn P.W. 1984. Widespread coral mortality and the 1982-83 El Niño warming event. Environmetal Conservation 11: 133-146.Google Scholar
  12. Glynn P.W. 1991. Coral reef bleaching in the 1980s and possible connections with global warming. Trends Ecology Evolution 6: 175-179.Google Scholar
  13. Glynn P.W. 1993. Coral reef bleaching: ecological perspectives. Coral Reefs 12: 1-17.Google Scholar
  14. Glynn P.W. 2001. History of significant coral bleaching events and insights regarding amelioration. In: Salm R.V. and Coles S.L. (eds) Coral Bleaching and Marine Protected Areas. Proceedings of the Workshop on Mitigating Coral Bleaching Impact Through MPA Design, Bishop Museum, Honolulu, Hawaii, May 2001. Asia Pacific Coastal Marine Program Report # 0102, The Nature Conservancy, Honolulu, Hawaii, 118 pp.Google Scholar
  15. Glynn P.W. and D'Croz L. 1990. Experimental evidence for high temperature stress as the cause of El Niño-coincident coral mortality. Coral Reefs 8: 18-191.Google Scholar
  16. Goreau T.J. and Hayes R.M. 1994. Coral bleaching and ocean 'hot spots'. Ambio 23: 176-180.Google Scholar
  17. Goreau T., McClanahan T. and Hayes R. 2000. Conservation of coral reefs after the 1998 global bleaching event. Conservation Biology 14: 5-15.Google Scholar
  18. Harriott V.J. 1985. Mortality rates of scleractinian coral before and during a mass bleaching event. Marine Biology Progress Series 21: 81-88.Google Scholar
  19. Hoegh-Guldberg O. 1999. Climate change, coral bleaching and the future of the world's coral reefs. Marine Freshwater Research 50: 839-866.Google Scholar
  20. Hoegh-Guldberg O. and Salvat B. 1995. Periodic mass-bleaching and elevated sea temperatures: bleaching of outer reef slope communities in Moorea, French Polynesia. Marine Ecology Progress Series 121: 181-190.Google Scholar
  21. Jordan I.E. and Samways M.J. 2001. Recent changes in coral assemblage of South African coral reef with recommendations for long term monitoring. Biodiversity and Conservation 10: 1027-1037.Google Scholar
  22. Jokiel P.L. and Coles S.L. 1977. Effects of temperature on the mortality and growth of Hawaiian reefs corals. Marine Biology 43: 201-208.Google Scholar
  23. Lesser H.R., Stocha W.R., Tapely D.W. and Shick J.M. 1990. Physiological mechanisms of bleaching in coral reef anthozoans: effects of irradiance, ultraviolet radiation and temperature on activities of protective enzymes against active oxygen. Coral Reefs 8: 225-232.Google Scholar
  24. Marshall P.A. and Baird A.H. 2000. Bleaching of corals on the Great Barrier Reef: differential susceptibilities among taxa. Coral Reefs 19: 155-163.Google Scholar
  25. McClanahan T.R. 2000. Bleaching damage and recovery potential of Maldivian coral reefs. Marine Pollution Bulletin 40: 587-597.Google Scholar
  26. McClanahan T.R., Muthiga N.A. and Mangi S. 2001. Coral and algal changes after the 1998 coral bleaching: interaction with reef management and herbivores on Kenyan reefs. Coral Reefs 19: 380-391.Google Scholar
  27. Ramsay P.J. and Mason T.R. 1990. Development of a type model for Zululand coral reefs, Sodwana Bay, South Africa. Journal of Coastal Research. 6: 829-852.Google Scholar
  28. Riegl B. 1993. Taxonomy and ecology of South African reef corals. Ph.D. Thesis, University of Cape Town South africa.Google Scholar
  29. Riegl B., Schleyer M.H., Cook P.J. and Branch G.M. 1995. Structure of Africa's southernmost coral communities. Bulletin of Marine Science 56: 676-691.Google Scholar
  30. Sheppard C.R.C. 1999. Coral decline and weather patterns over 20 years in the Chagos Archipelago, Central Indian Ocean. Ambio 28: 472-478.Google Scholar
  31. Turner J., Hardman E., Klaus R., Fagoonee I., Daby D., Baghooli R. and Persands S. 2000a. The reefs of Mauritius. In: Souter D., Obura D. and Linden O. (eds) Coral Reef Degradation in the Indian Ocean. CORDIO/SAREC, Stockholm, Sweden, pp. 94-107.Google Scholar
  32. Turner J., Klaus R. and Engelhardt U. 2000b. The reefs of the granitic islands of the Seychelles. In: Souter D., Obura D. and Linden O. (eds) Coral Reef Degradation in the Indian Ocean. CORDIO/SAREC, Stockholm, Sweden, pp. 94-107Google Scholar
  33. Walters R.D.M. and Samways M.J. 2001. Sustainable dive ecotourism on a South African coral reef. Biodiversity and Conservation 10: 2167-2179.Google Scholar
  34. Ware J.R., Fauntin D.G. and Buddemeier R.W. 1996. Patterns of coral bleaching: modeling the adaptive bleaching hypothesis. Ecological Modeling 84: 199-214.Google Scholar
  35. Ware J.R. 1997. The effect of global warming on coral reefs: acclimate or die. Proceedings of the 8th International Coral Reef Symposium 1: 527-532.Google Scholar
  36. Wilkinson C., Linden O., Cesar H., Hodgson G., Rubens J. and Strong A. 1999. Ecological and socioeconomic coral mortality in the Indian Ocean: an ENSO impact and a warming of future change? Ambio 28: 188-196.Google Scholar
  37. Williams E.H. Jr. and Bunkely-Williams L. 1988. Circumtropical coral reef bleaching in 1987-1988. Abstract, 6th International Coral Reef Symposium, Australia, 106 p.Google Scholar
  38. Williams E.H. Jr. and Bunkley-Williams L. 1990. The world-wide coral reef bleaching cycle and related sources of coral mortality. Atoll Research Bulletin 335: 1-71.Google Scholar

Copyright information

© Kluwer Academic Publishers 2004

Authors and Affiliations

  • C.D. Floros
    • 1
  • M.J. Samways
    • 1
    • 2
  • B. Armstrong
    • 3
  1. 1.Invertebrate Conservation Research Centre, School of Botany and ZoologyUniversity of Natal, PietermaritzburgScottsvilleSouth Africa
  2. 2.Department of Entomology and NematologyUniversity of StellenboschMatielandSouth Africa(e-mail
  3. 3.KwaZulu-Natal Wildlife, Ecological AdviceCoast, DurbanSouth Africa

Personalised recommendations