Patterns of coral damage associated with the 2004 Indian Ocean tsunami at Mu Ko Similan Marine National Park, Thailand

On 26 December 2004, a severe earthquake in Sumatra caused a series of tsunami waves to strike southwestern coastal areas of Thailand. In this study, we investigated the patterns of tsunami-related damage to coral reefs at Mu Ko Similan Marine National Park. The results showed that the percent of damaged corals ranged from 7.2% to 39.7% of the total live coral cover, and the intensity of the coral damage was high at depths deeper than 10 metres at most study sites. In addition, massive and tabulate coral forms were the most susceptible to tsunami damage. The surveys also revealed that a high degree of coral damage occurred where the reef slope gradually dropped away from the shoreline. Therefore, coral communities and coastal profiles can be major factors influencing the movement of the currents generated by the tsunami and consequently may affect the pattern of coral damage by the tsunami.