Analysis of coral reef diversity and its correlation to fish abundance in Biawak Island cluster areas

Abstract The importance of coral reefs for humans and marine biota must be conserved due to threat of climate change and anthropogenic pressures, one of which is in a cluster of small islands in Indramayu Regency, (comprising Biawak, Candikian and Gosong island). This study aims to assess the status of coral reefs in Indramayu (percent cover, diversity, uniformity, and dominancy of the coral reef ecosystem) as well as the potential correlation with fish abundance. Areas of interest were pre-determined using Lyzenga method, ground truth using the LIT (Line Intercept Transect), while genus-based fish abundance using UVC (Underwater Visual Census) method. This study revealed that the status of coral reefs is in moderate condition. The diversity index ranges from 1 to 3, and dominancy index is less than 0.50, indicating a stable reef community where no dominant genus is found in the community. The correlation between fish abundance and the live coral cover percentage showed a positive linear association. These results indicate that current coral reef ecosystems seem unaffected by anthropogenic pressures. It is expected that these results can be used by local authorities to conserve coral reef ecosystems and marine biota, and to maintain the sustainability of community livelihoods.