Scientia Marina, Vol 78, No 3 (2014)

Mass coral bleaching in the northern Persian Gulf, 2012

Javid Kavousi
Graduate School of Engineering and Science, University of the Ryukyus , Japan

Parviz Tavakoli-Kolour
Young Researchers and Elits Club, Bandar Abbas Branch, Islamic Azad University , Iran, Islamic Republic of

Maria Mohammadizadeh
Department of Environmental Management, Islamic Azad University , Iran, Islamic Republic of

Arezoo Bahrami
Young Researchers and Elits Club, Bandar Abbas Branch, Islamic Azad University , Iran, Islamic Republic of

Abbas Barkhordari
Young Researchers and Elits Club, Bandar Abbas Branch, Islamic Azad University , Iran, Islamic Republic of


Coral bleaching events due to elevated temperatures are increasing in both frequency and magnitude worldwide. Mass bleaching was recorded at five sites in the northern Persian Gulf during August and September 2012. Based on available seawater temperature data from field, satellite and previous studies, we suggest that the coral bleaching threshold temperature in the northern Persian Gulf is between 33.5 and 34°C, which is about 1.5 to 2.5°C lower than that in the southern part. To assess the bleaching effects, coral genera counted during 60-minute dives were categorized into four groups including healthy, slightly bleached (< 50% bleached tissue), mostly bleached ( > 50% bleached tissue) and fully bleached colonies. The anomalously high sea surface temperature resulted in massive coral bleaching (~84% coral colonies affected). Acropora spp. colonies, which are known as the most vulnerable corals to thermal stress, were less affected by the bleaching than massive corals, such as Porites, which are among the most thermo-tolerant corals. Turbid waters, suggested as coral refugia against global warming, did not protect corals in this study since most affected corals were found in the most turbid waters. The 2012 bleaching in the northern Persian Gulf was relatively strong from the viewpoint of coral bleaching severity. Long-term monitoring is needed to understand the actual consequences of the bleaching event on the coral reefs and communities.


coral bleaching; thermal threshold; Iranian islands; Persian Gulf

Full Text:



Baker A.C., Starger C.J., McClanahan T.R., et al. 2004. Corals' adaptive response to climate change. Nature 430: 741. PMid:15306799

Bastidas C., Bone D., Croquer A., et al. 2012. Massive hard coral loss after a severe bleaching event in 2010 at Los Roques, Venezuela. Rev. Biol. Trop. 60: 29-37.

Buchheim J. 2005. Coral reef bleaching. Journal of Odyssey Expeditions, Tropical Marine Biology Voyages, 10 pp. PMCid:PMC1739595

Budd A.F., Fukami H., Smith N.D., Knowlton N. 2012. Taxonomic classification of the reef coral family Mussidae (Cnidaria: Anthozoa: Scleractinia). Zool. J. Linn. Soc. 166: 465-529.

Burt J., Al-Harthi S., Al-Cibahy A. 2011. Long-term impacts of coral bleaching events on the world's warmest reefs. Mar. Environ. Res. 72: 225-229. PMid:21880360

Coles S.L., Brown B.E. 2003. Coral bleaching-capacity for acclimatization and adaptation. Adv. Mar. Biol. 46: 183-223.

Coles S.L., Riegl B.M. 2013. Thermal tolerances of reef corals in the Gulf: A review of the potential for increasing coral survival and adaptation to climate change through assisted translocation. Mar. Pollut. Bull. 72: 323-332. PMid:23058810

Dalton S.J., Carroll A.G. 2011. Monitoring coral health to determine coral bleaching response at high latitude eastern Australian reefs: an applied model for a changing climate. Diversity 3: 592-610.

Fabricius K.E., Hoegh-Guldberg O., Johnson J., et al. 2007. Vulnerability of coral reefs of the Great Barrier Reef to climate change. In: Johnson J.A., Marshall P.A. (eds), Climate change and the Great Barrier Reef: a vulnerability assessment. The Great Barrier Reef Marine Park Authority, Townsville, pp. 515-554.

Fabricius K.E., De'ath G., Puotinen M., et al. 2008. Disturbance gradients on inshore and offshore coral reefs caused by severe tropical cyclone. Limnol. Oceanogr. 53: 690-704.

Golbuu Y., Victor S., Penland L., et al. 2007. Palau's coral reefs show differential habitat recovery following the 1998-bleaching event. Coral Reefs 26: 319-332.

Goreau T.J., Hayes R.L. 1994. Coral bleaching and ocean hot spots. Ambio 23: 176-180.

Goreau T.J., Hayes R.L. 2005. Global coral reef bleaching and sea surface temperature trends from satellite-derived Hotspot analysis. World Resource Rev. 17: 254-293.

Goreau T., McClanahan T., Hayes R., et al. 2000. Conservation of coral reefs after the 1998 global bleaching event. Conserv. Biol. 1: 5-15.

Goreau T.J., Hayes R.L., McAllister D. 2005. Regional patterns of sea surface temperature rise: implications for global ocean circulation change and the future of coral reefs and fisheries. World Resource Rev. 17: 350-374.

Guest J.R., Baird A.H., Maynard J.A., et al. 2012. Contrasting patterns of coral bleaching susceptibility in 2010 suggest an adaptive response to thermal stress. PLoS One 7: e33353. PMid:22428027 PMCid:PMC3302856

Hill J., Wilkinson C. 2004. Methods for ecological monitoring of coral reefs. Australian Institute of Marine Science, Townsville, 117 pp.

Kavousi J., Seyfabadi J., Rezai H., et al. 2011. Coral reefs and communities of Qeshm Island, the Persian Gulf. Zool. Stud. 50: 276-283.

Kavousi J., Tavakoli-Kolour P., Barkhordari A., et al. 2013. Mass mortality of Porites corals on northern Persian Gulf reefs due to sediment-microbial interactions. Int. J. Mar. Sci. 3: 306-310.

Lesser M.P. 2011. Coral Bleaching: Causes and Mechanisms. In: Dubinksy Z., Stambler N. (eds), Coral Reefs: an ecosystem in transition. Springer Science, New York, pp. 405-419.

Loya Y., Sakai K., Yamazato K., et al. 2001. Coral bleaching: the winners and the losers. Ecol. Lett. 4: 122-131.

McClanahan T.R. 2004. The relationship between bleaching and mortality of common corals. Mar. Biol. 144: 1239-1245.

Meissner K.J., Lippmann T., Sen Gupta A. 2012. Large-scale stress factors affecting coral reefs: open ocean sea surface temperature and surface seawater aragonite saturation over the next 400 years. Coral Reefs 31: 309-319.

Miller M.W., Piniak G.A., Williams D.E. 2011. Coral mass bleaching and reef temperatures at Navassa Island, 2006. Est. Coast. Shelf Sci. 91: 42-50.

Mohammadizadeh M., Tavakoli-kolour P., Rezai H. 2013. Coral reefs and community around Larak Island (Persian Gulf). Caspian J. Appl. Sci. Res. 2: 52-60.

Rezai H., Wilson S., Claereboudt M., et al. 2004. Coral reef status in the ROPME Sea area, Arabian/Persian Gulf, Gulf of Oman and Arabian Sea. In: Wilkinson C. (ed), Status of coral reefs of the world. Vol. 1. Australian Institute of Marine Science, Townsville, Queensland, pp. 155-170.

Rezai H., Kamrani E., Samimi-Namin K., et al. 2010. Coral degradation, distribution and abundance around Larak, Hengam and Kish Islands, Persian Gulf. Iranian National Centre for Oceanography, Tehran.

Riegl B. 2002. Effects of the 1996 and 1998 positive sea surface temperature anomalies on corals, coral diseases and fish in the Arabian Gulf (Dubai, UAE). Mar. Biol. 140: 29-40.

Riegl B., Purkis S. 2009. Model of coral population response to accelerated bleaching and mass mortality in a changing climate. Ecol. Model. 220: 192-208.

Riegl B.M., Purkis S.J. (eds). 2012. Coral reefs of the Gulf (Vol. 3). Springer DE, Germany, 250 pp.

Riegl B.M., Purkis S.J., Al-Cibahy A.S., et al. 2011. Present limits to heat-adaptability in corals and population-level responses to climate extremes. PLoS One 6: e24802. PMid:21949755 PMCid:PMC3176771

Sheppard C.R.C. 2003. Predicted recurrences of mass coral mortality in the Indian Ocean. Nature 425: 294-297. PMid:13679917

Sheppard C.R.C. 2006. Longer term impacts of climate change. In: Cote I., Reynolds J. (eds), Coral Reef Conservation. Cambridge University Press, Cambridge, pp. 264-290.

Sheppard C.R.C. 2009. Large temperature plunges recorded by data loggers at different depths on an Indian Ocean atoll: comparison with satellite data and relevance to coral refuges. Coral Reefs 28: 399-403.

Sheppard C.R.C., Price P., Roberts C. 1992. Marine ecology of the Arabian region. Academic Press, London, 359 pp.

Takahashi S., Nakamura T., Sakamizu M., et al. 2004. Repair Machinery of symbiotic photosynthesis as the primary target of heat stress for reef-building corals. Plant Cell Physiol. 45: 251-255. PMid:14988497

Thoppil P.G., Hogan P.J. 2010. A modeling study of circulation and eddies in the Persian Gulf. J. Phys. Oceanogr. 40: 2122-2134.

Wagner D.E., Kramer P., van Woesik R. 2010. Species composition, habitat, and water quality influence coral bleaching in south-eastern Florida. Mar. Ecol. Prog. Ser. 408: 65-78.

Wilkinson C. 2004. Status of Coral Reefs of the World. Australian Institute of Marine Science, Townsville.

Wilkinson C. 2008. Status of Coral Reefs of the World: 2008. Australia: Global Coral Reef Monitoring Network and Reef and Rainforest Research Center, Townsville.

van Woesik R., Houk P., Isechal A.L., et al. 2012. Climate-change refugia in the sheltered bays of Palau: analogs of future reefs. Ecol. Evol. 2: 2474-2484. PMid:23145333 PMCid:PMC3492774

Copyright (c) 2014 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Contact us

Technical support