Coral recruitment and its relationship to hard coral cover in the Derawan Islands, East Kalimantan

Abstract

Coral recruitment is the process when coral larvae settle to the substrate and establish themselves as a reef community. The success of coral recruitment is very important for the sustainability of coral reefs in an area, including the Derawan Islands which develop underwater tourism. Observations on coral reef recruitment were carried out in the Derawan Islands. This study aimed to determine the density of coral recruitment, hard coral cover, and the relationship between coral recruitment and hard coral cover. Data were collected using the Underwater Photo Transect method at 11 stations in the Derawan Islands. The results showed that coral recruitment in the Derawan Islands was low, ranging from 1.41 to 3.13 colonies.m−2. Hard coral cover was categorized as “moderate” with an average of 28.04% (+SE=3.63%). The relationship between coral recruitment and hard coral cover occurred for medium-sized juvenile corals (3-6 cm). Their negative relationship was shown by the presence of more medium-sized juvenile corals in areas with lower hard coral cover. The large availability of stable substrates such as DCA in areas with low hard coral cover can increase the potential for coral reef ecosystems to recover naturally.