Diversity and abundance of macrobenthos in a subtropical estuary, Bangladesh

Soft bottom macrobenthos are important component of the marine and coastal trophic chain. There has been sparse information regarding the distribution of soft bottom macrobenthos form the coastal water of Bangladesh. Consequently, the present study was an effort to reveal the diversity and abundance of macrobenthos in the Feni Estuary in a seasonal pattern together with the hydrological factors. A total of 17 taxa families of soft-bottom invertebrates were found over the two sampling seasons. The current study yielded a total number of 34,726 ind./m 2 (mean 2480ind./m 2) including 18,909ind./m 2 in wet season (mean 2682ind./m 2) and 15,817 ind./m 2 in dry season (2259ind./m 2). The highest density of soft-bottom invertebrates was in the wet season while the lowest number in the dry season. A total of 5 groups of macrobenthos were found over the two sampling seasons. The dominant group was Polychaeta that contributed 43.60% of the total soft-bottom invertebrates. The values of biodiversity indices were higher in dry season compare to the wet season in most of the sampling station during the study period.