Coral diversity and benthic reef communities in Sepangar Bay, Sabah

• Main Author: Mohd Firdaus Akmal Nooramli
• Format: Thesis
• Language: English; English
• Published: 2020
• Subjects: QH501-531 Life
• Online Access: https://eprints.ums.edu.my/id/eprint/41054/1/24%20PAGES.pdf; https://eprints.ums.edu.my/id/eprint/41054/2/FULLTEXT.pdf; https://eprints.ums.edu.my/id/eprint/41054/

Sepangar Bay is located approximately ten kilometres from Kata Kinabalu city. The bay is unprotected, and it is surrounded by the Sepangar Royal Malaysian Navy base, Sepangar Bay Container Port, Sepangar Bay Oil Terminal, several villages and nearshore islands. Two rivers, Menggatal River and Inanam River discharge into the bay. The area is rapidly losing its original mangrove, seagrass and coral reef habitats to rapid urbanisation. This study focuses on the percentage coral cover, coral diversity and environmental parameters that limit reef development in Sepangar Bay. Seven reef areas along the coast of Sepangar Bay and nearby islands (Sepangar Island and Pulau Island) were surveyed between 2015 to 2017. In each area, three replicate transects of 100 metres were deployed at approximately 5 - 10m depth. A total of 50 photo quadrats were taken along each transect and analysed using Coral Point Cover with Excel extensions (CPCe) software. Water physico-chemical parameters and sediment particle size were analysed for each site. The percentage coral cover ranged between 11.11 % (Inner Sepangar Bay) and 52.86% (Udar Island), with the lowest recorded at the sheltered reef areas within the inner bay and the highest coverage at the islands and along the exposed coastline. Two areas were considered as Good, three as Fair while two were determined to be Poor. The sheltered areas had a higher percentage of silt and coral rubble on the reefs compared to others and significant difference in percentage coral cover among the areas was observed between sheltered areas and island, exposed areas. A total of 53 coral genera was identified with nine genera present at all sites and three genera observed at all transects (Dipsastraea spp., Favites spp. Porites spp.). Two sites recorded 44 genera (Udar Island and Tg. Gaya-Tg. Saban) which were the highest among all sites while the lowest had only 15 genera identified (Inner Sepangar Bay). According to Canonical Correspondence Analysis (CCA), turbidity, nitrate and phosphate were the parameters that displayed strong association in restricting reef development as they were heavily associated with silt and fine silt particles while the hard coral were more associated with Light and Luminescence Dissolved Oxygen (LOO) besides showing negative association with turbidity, nitrate and phosphate. This was supported by the distribution of the areas on the scatter plot where areas with high percentage coral cover was associated with light and LOO while areas with poor coral cover was associated with turbidity, nitrate and phosphate. Most coral genera showed negative association with those limiting parameters and displayed heavy association towards Light, LOO with preference of Rock and Sand substrate. However, several coral genera exhibit survivability and adaptability towards the limiting parameters and fine silt particles. The corals in Sepangar Bay were damaged more by bleaching compared to other damages observed where six out of seven areas had Bleached Coral Point. There are also several observations on damage by Crown-of-Thorns sea star and White Band Disease although the number is low. Hence, areas with higher percent coral cover had better environmental parameters that enables the coral reefs to sustain and remain healthy while poor coral cover areas were exposed to natural and anthropogenic stressors.