Genera Composition and Status of Stony Coral at Koh Ngai, Lan-ta National Park, Krabi, Thailand

Abstract

Thai coral reefs have been affected and destroyed from various direct and indirect human activities; such as, coral colony broken by fisherman anchor, coral tissue wounded by tourist standing on, water pollution and herbivore behavior influence by the over fish-feeding. Therefore, coral reef inventory and monitoring is needed in many tourist sites in Thailand. This study examined the current coral status at two sites (the North-East, NE and the South Station, S) of Koh Ngai, which is located on the Lan-ta National Park at Trang Province. The coral percent coverage and genus identification were done using photo quadrat transect method. A 90 m transect was laid horizontally to the shoreline in each of the two study sites. In total, 180 coral pictures were taken from each site site. Coral percent coverages were analyzed using CPCe program. NE represented higher genera than S with 14 and 20 genera respectively. However, Porites was the dominant genus in the both stations. The similarity of coral genera composition between stations and within station were analysed by UPGMA cluster analysis. The similarity between the two stations was 42.24%. The similarity of coral genera composition within station NE and S station was 49.46% and 60.14% respectively. The ratio of healthy corals to dead corals in NE station was 1:1 with 41.97±5.09% and 58.02±4.70%, and in S station was 1:2 with 39.10±5.99% and 59.23±6.56% respectively. The evaluation of coral ratio at Koh Ngai can be concluded to fair condition for NE stations and declining for S stations. This result would be useful for future comparable status the tourist increasing.