Monitoring and Assessment of Coral Reef in Spermonde Archipelago, South Sulawesi, Indonesia

Abstract

<p> Four coral reef sites were observed in Spermonde Archipelago, off Southwest Sulawesi, Indonesia The sites were located at different distances from the mainland: Kayangan reef ('affected' site) is the closest and Samalona, Barang Lompo, and Kapoposan ('comparison' sites) are successively farther from the mainland and Ujung Pandang city. </p> <p> Coral cover, number of species at 3m and 1Om depths, and coral growth rates (Porites lobata) were observed to describe coral conditions. Environmental parameters suspended particulate matter (SPM), resuspended sediment, salinity, clarity, chlorophyll a, phosphate, nitrate, ammonium and o15N values ofcoral tissue (P. lobata) were also investigated to assess possible 'stress' factors on the reefs. </p> <p> Average coral cover at the 'affected' site was very low (14 %), compared to the other sites: Samalona (44.3 %), B. Lompo {47.2 %) and Kapoposan {66.6 %). Also, the lowest total number ofspecies occurred at Kayangan (42 spp.), compared to the other sites: Samalona {62 spp.), B. Lompo {71·spp.) and Kapoposan (80 spp.) </p> <p> Environmental parameters indicated that sedimentation and eutrophication (sewage) were the main 'stress' factors at Kayangan reef: while human disturbances such as fish bombing. anchoring. coral collection, and other activities affected Samalona and B. Lompo more. High coral cover and number of species at Kapoposan reef indicated fewer 'stress' factors. </p> <p> Coral growth rates showed a different trend from coral cover and total number of species. The highest coral growth rates occurred at B. Lompo (15.9 ± 0.8 mm yr-1) followed by Kayangan, Samalona and Kapoposan. Based on environmental parameters, it seemed that coral growth rates were higher at more eutrophic reefs, but slower at certain maximum critical nutrient values. </p> <p> δ^15 values of coral tissue found in this study are positively correlated with chlorophyll a, dissolved nutrients, and sedimentation rates. The high δ^(15)N values at Kayangan (8.03 ± 0.62 %) support the idea that this site was affected by human waste and sewage. </p>