Determining coral diversity around engineered artificial reefs in Teluk Kalong Besar, Pulau Redang using CPCE

Abstract

There exists a need to understand and seek scientific information to explore coral habitat that could generate around artificial reefs in order to support works to conserve coral reefs. The serious decline of fish catches in the coastal waters of Peninsular Malaysia had prompted the government to take steps to enhance the demersal fishery resource. Hydrocheese which is a hollow porous block, is a locally innovated multi-design structure which functions both as an artificial reef and a submerged breakwater system. Eight Hydrocheese blocks were deployed in Telok Kalong Besar waters, Pulau Redang in 2007 and 2009. This paper highlights works to collect and establish scientific information on the diversity of coral colonies around the Hydrocheese artificial reef units when placed at an underwater site. The images of the coral growth around the Hydrocheese units were captured by divers using high performance underwater camera. Pictures that were taken in the field were subsequently imported into an image analysis software. The CPCe software(Coral Point Count with Excel extensions) is a Microsoft-based software that provides a tool for determining coral cover using transect photographs. A specified number of spatially random points were distributed on a transect image and the features underlying the points were user-identified. Coverage statistics were then calculated and the results transferred to Excel spreadsheets automatically. Random Point Counts Methods to subsample the previous picture sets were used. Data points were randomly selected and overlaid onto the pictures using the software from which habitat profiles were calculated. The data analysis was made after image processing which involved species diversity, coral cover and other required data, using suitable equation and formulae such as the Shannon-Weaver diversity index(H) and the Simpson Index of Diversity (D). The values of Shannon Diversity Index of corals (H) and the Simpson Index of Diversity (D) were found to be 1.27 and 0.67 respectively in this study.