| Abstrakt: |
This study was conducted to determine the biodiversity and community structure (species composition, richness, diversity, evenness, dominance and clustering) of macroalgae found in Tanjung Merah waters, Rap-rap waters and Totok Bay, North Sulawesi Indonesia. The line transect method was used to identify and quantify the macroalgae abounding the three established stations divided into three transects each site. Species richness, diversity, evenness and dominance indices were calculated to determine diversity of macroalgae along the study area. A total of 16 different species of macroalgae were identified in the study area belonging Rhodophyta (Rhodomelaceae, Lithophyllaceae, Gracilariaceae, Galaxauraceae, Cystocloniaceae, Halymeniaceae), Phaeophyta (Dictyotaceae) and Chlorophyta (Codiaceae, Caulerpaceae, Halimedaceae, Ulvaceae, Dasycladaceae, Cladophoraceae). The most abundant macroalgae species across the three sites were: Halimeda opuntia (Tanjung Merah and Totok Bay), and Halimeda macroloba (Rap-rap). The macroalgae species identified also has different densities ranging from 0.03 to 5.93 /m2. Green macroalgae Halimeda macroloba had the highest density, and Codium fragile, Chaetomorpha crassa, Caulerpa racemosa and Hypnea cervicornis had the lowest density. Species richness index, diversity index, evenness index and dominance index were calculated to determine diversity of macroalgae along the study area. Tanjung Merah obtained the highest species richness and Totok Bay obtained the lowest species richness. On the other hand, Totok Bay recorded the highest diversity and Rap-rap recorded the lowest diversity. Evenness index was highest at Totok Bay, while the lowest was at Rap-rap. The dominance index was the highest at Rap-rap, while the lowest at Tanjung Merah. The three sampling sites are divided into 3 groups based on an abundance of 16 species of macroalgae. The three groups are Group I (Tanjung Merah), Group II (Rap-rap), and Group III (Totok Bay). Apparently, the three site groups are related to the type of sediment. [ABSTRACT FROM AUTHOR] |
