Assessment of Macrobenthic Community Structure: An Approach to Coastal Water Pollution in Bangladesh

The present study was designed to explore diversity of benthos in the South-Western coastal waters
of Bangladesh with the following objectives. A research on the assemblages of benthic macro faunal
community in the coastal areas of Bangladesh was conducted during February-March, 2015 following
the standard methods to assess the status of environmental pollution. Macrobenthic species
composition in Bakkhali river estuary showed the maximum numbers of Polycheate (46%) followed by
gastropods- 23%, atrhropods-9%, bivalvia-8% and oligochaete-6%. The abundance (r=0.846) and
species richness (r=0.864) of the macrobenthic communities were significantly influenced by the
water salinity of the sampling sites (p ≤ 0.05). Both the study areas namely the Bakkhali River Estuary
and the Meghna River Estuary showing the highest (3909 ± 540 ind./m2) and lowest (2236 ± 689
ind./m2) density of benthic macrofaunal abundance respectively might be considered as moderately
polluted areas according to the results obtained from Shannon-Wiener index of species diversity (2.69
± 0.13 and 2.00 ± 0.11 respectively) and Margalef’s species richness (2.21 ± 0.43 and 1.36 ± 0.11
respectively). The coastline along the South-Eastern part of Bangladesh has high fisheries resources
and the fisheries production of the estuarine areas of that coast is higher than other coastal areas of
the country. Environmental pollution is believed to be the major constraints of fisheries production of
an area. Therefore, it is plausible that the macrobenthic community explained in the present study
might be a key future outline to assess the status of coastal water pollution of those concerned areas
of Bangladesh.