Density and diversity of macrobenthos on seagrass beds in Sungai Pulai Estuary, Johor

Abstract

Research on benthic fauna communities inhabiting seagrass meadow and their abundances received little attention in Malaysia. This present study aims to address this issue, determining the density and diversity of macrobenthos on seagrass beds in Sungai Pulai estuary, Johor. Sampling was done in December as the sampling sites were experienced the lowest tide during this period. Data was analyzed for density of macrobenthos (individual m- 2 ), diversity index (H') of Shanon-Weinner (1949), richness index ( d) of Margalef (1958) and evenness index (J') of Pielou (1975) by using PRIMER software package. Overall, a total of 1798 macrobenthos individuals were collected in 81 cores and the densities of macrobenthos at study sites ranged from 207.1563-3841.808 2 • The highest density of macrobenthos was recorded in Merambong (1807.91 ind/m 2 ind/m to 3841.808 ind/m 2 ) followed by Tanjung Pelepas (470.8098 ind/m 2 to 1186.441 2 ind/m ) and Sungai Duku (207.1563 ind/m 2 to 621.4689 indlm 2 ). In terms of diversity, the highest diversity index was encountered at Tanjung Pelepas (H'= 2.0627), followed by Merambong (H'= 1.4187) and Sungai Duku (H'= 1.3912). It is shown that the macrobenthos were mostly comprised of polychaetes, mollusks, and crustaceans. Physical and environmental factors are thought to be responsible for the large variation in macrobenthos assemblage structure within sites.