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The Maldives' Corals Seven Years after the 1998 Bleaching Event
McClanahan, T.R. and Muthiga, N.A. 2014. Community change and evidence for variable warm-water temperature adaptation of corals in Northern Male Atoll, Maldives. Marine Pollution Bulletin 80: 107-113.

The authors write that "the warm phase of the 1998 El Niņo Southern Oscillation was among the strongest warm water anomalies since instrumental records [began to be kept]," citing Enfield (2001); and they say it "created large-scale coral bleaching and mortality throughout the tropics and was most severe in many reef areas of the western Indian Ocean," citing Wilkinson et al. (1999) and Goreau et al. (2000). The worst hit of them all, however, were the Maldivian reefs, "with hard coral cover dropping to as low as 2% of the substratum (Goreau et al., 2000; McClanahan, 2000; Edwards et al., 2001), whereas cover estimates prior to the mid-1960s were typically over 50% of the substratum and dominated by large stands of Acropora (Sheer, 1971; Davies et al., 1971)," some species of which, as they describe it, "were not observed a year after the event (McClanahan, 2000)." So what was the situation seven years after the event?

What was done
McClanahan and Muthiga provide what they refer to as "a descriptive analysis of the North Male, Maldives, seven years after the 1998 bleaching disturbance to determine the state of the coral community composition, the recruitment community, evidence for recovery, and adaptation to thermal stress."

What was learned
The two researchers report that "overall, hard coral cover recovered at a rate commonly reported in the literature but with high spatial variability and shifts in taxonomic composition." More specifically, they found that "massive Porites, Pavona, Synarea and Gonipora were unusually common in both the recruit and adult communities," while "coral recruitment was low and some coral taxa, namely Tubipora, Seriatopora and Stylophora, were rarer than expected." In addition, they say that "a study of the bleaching response to a thermal anomaly in 2005 indicated that some taxa, including Leptoria, Platygyra, Favites, Fungia, Hydnophora and Galaxea astreata, bleached as predicted while others, including Acropora, Pocillopora, branching Porites, Montipora, Stylophora and Alevopora, bleached less than predicted."

What it means
McClanahan and Muthiga say their findings suggest that (1) there exist "variable-adaptation potentials among the taxa and considerable potential for ecological reorganization of the coral community," that (2) "natural selective processes are underway," and that (3) "promoting resistant coral taxa through selective breeding and transplanting could have some management potential."

Clearly, therefore, with a little local help from mankind, earth's corals should continue to be found throughout the world for as long as we are so found and are willing to do our part in maintaining at least a half-way-decent coastal environment for them.

Davies, P.S., Stoddart, D.R. and Sigee, D.C. 1971. Reef forms of Addu Atoll, Maldive Islands. Symposium of the Zoological Society of London 28: 217-259.

Edwards, A.J., Clark, S., Zahir, H., Rajasuriya, A., Naseer, A. and Rubens, J. 2001. Coral bleaching and mortality on artificial and natural reefs in Maldives in 1998, sea surface temperature anomalies and initial recovery. Marine Pollution Bulletin 42: 7-15.

Enfield, D.B. 2001. Evaluation and historical perspective of the 1997-1998 El Niņo-Southern Oscillation event. Bulletin of Marine Science 69: 7-25.

Goreau, T., McClanahan, T., Hayes, R. and Strong, A. 2000. Conservation of coral reefs after the 1998 global bleaching event. Conservation Biology 14: 5-15.

McClanahan, T. 2000. Bleaching damage and recovery potential of Maldivian coral reefs. Marine Pollution Bulletin 40: 587-597.

Scheer, G. 1971. Coral reefs and coral genera in the Red Sea and Indian Ocean. Symposium of the Zoological Society of London 28: 329-367.

Reviewed 23 July 2014