Measurement of coral bleaching
Measurement of coral bleaching was conducted along the coastlines of Ranong and Phang Nga in
May 2005 (Fig. 2). The surveys were performed using line transects of 20–60 m in length at Ranong province with a total of 52 sampling stations(15 stations at Phayam island, 18 stations at Kam Yai and Kam Nui islands, 9 stations at Khang Khao island, 5 stations at Lan island, and 5 stations at Khai Yai island). The length of line transects depended on the length of the reef flat and reef slope. The measurement of bleaching started from reef flat and ended at the end of reef slope. Since the coral reef of Surin and Torinla islands (Surin Marine National Park) at some stations have a long reef flat and very deep reef slope, the transect lines were set up at
three depths (about 15, 20, and 25 m) parallel to the shoreline. The measurement of bleaching was conducted at 36 sampling stations in Surin Marine National Park. The percentage of coral bleaching was calculated by measuring the proportion of living coral and bleached coral, along the transect lines.