Reef Fish Diversity and IUCN Status at Racha Yai Island, Thailand

Abstract

In this study, the purpose was to study the diversity and status of fish species in Coral reefs (i.e., reef fish diversity, richness, evenness, and IUCN conservation status) were studied at Patok and Khonkae Bays, Racha Yai Island, southern Thailand. In Patok bay, three 50-m permanent line transects, and in Khonkae bay, four 50-m permanent line transects (each covering 250 m²) were set up along the reef slope at 8-10 m depth. Each transect area was separated from each other by 10 m. All reef fishes from each transect were identified, counted, and recorded. The IUCN conservation status of each fish species was recorded. Shannon index (H), Margalef’s richness (D), and Pielou’s evenness (e) were calculated. The differences in fish diversity, richness, evenness, and IUCN conservational status were tested between Patok and Khonkae Bays. We observed that numbers of fish species, individuals, orders, families, Shannon diversity, and species richness did not differ between Patok and Khonkae Bays but evenness was higher in Khonkae Bay than in Patok Bay. In addition, numbers of fishes from different orders were not different between two bays, whereas, more fishes were observed from Perciformes order than other orders (i.e., Tetraodontiformes, Syngnathiformes, and Scorpaeniformes) in both bays. Based on IUCN conservation status, most of the fish species were from ‘not evaluated’ and ‘data deficient’ groups, whereas, only one fish species (Epinephelus malabaricus) from Patok Bay was nearly threatened. Our results show that fish species was more evenly distribute in Khonkae Bay than in Patok Bay. This is because in Patok Bay, there were high numbers of Lutjanus biguttatus with tatoal of 62% compared to other fish species.