Reef fishes abundance and assemblages in six islands (Kapoposang, Lanyukang, Lumu-Lumu, Badi, Ballang Lompo and Karanrang island) of spermonde archipelago during El Nino 2016, South Sulawesi, Indonesia

Abstract

Overfishing in the Spermonde Archipelago has resulted in long-term changes in fishery composition and structure, as well as in resource utilization patterns. Later on, the patterns of resource use are highly variable, with new activities and new target species, e.g., ornamental corals and intensive coral reef fishery being a relatively recent phenomenon in the area. This research aims at measuring the coral fishes abundance and assemblages in six islands (Kapoposang, Lanyukang, Lumu-Lumu, Badi, Ballang Lompo, and Karanrang), representing off-shore and in-shore of Spermonde Archipelago waters during the occurrence of the 2016 El Nino. Underwater Visual Census (UVC) method was done to measure coral fish abundance, once every seasonal interval, totaling four times for every island, on 70 meter transects covering an area of 350 m2 (2.5 m to the right and left and 5 m above). Fish species found were identified by following several coral fish identification books Data was analyzed for their total species abundance based on the family. Results showed that coral fish abundance by the family was found to be lowest (less than 10.000 individuals/hectare) all through the year in Karanrang Island. The most abundance was found in Lanyukang Island (84.600 individu/hectare) during the month of September, followed by Badi Island (59.971 individu/hectare). In February, fish abundance of 35. 743 and 46.886 individu/hectare were only found in Kapoposang and Badi islands. All in all, on average, Badi island showed for having relatively equal coral fish abundance in all four seasons. One hundred species were found in Lanyukang, while 78 species were found in Lumu-Lumu, totaling 136 species of coral fishes of 28 families. Coral fishes species always found in all trips were 20 species in Lanyukang and 11 species in Lumu-Lumu. Four species always found in both islands were Thalassoma hardwicke, Neoglyphidodon nigroris, Labroides dimidiatus, Cirrhilabrus ryukyuensis. Fishes found most abundance were from Labridae and Pomacentridae families, each of 31 and 30 species. The temporary conclusion was that Lanyukang has more species than Lumu-Lumu.