Identify the Relation of Biotic Factors, Sedimentation, and other Physio-Chemical Parameters; A Field Assessment on Karnawphuli Estuarine Environment

This study describes the influence of Sedimentation and other Physiochemical parameters of biotic factors and faunal assemblages in the Karnawphuli estuary, Bangladesh at the period of December 2015. A total of 22 phytoplankton, 9 zooplankton and 10 benthic species/ taxa belonging to annelids, molluscs, arthropods and Chaetognatha were recorded. Sub-surface water samples were collected from two stations: site-1 and site-2 namely Jetti no. 10 and Jetti no. 15 region of the Karnawphuli river estuary. Air-water temperature, Water transparency, water salinity, water pH and sediments of bottom layer were identified, observed and collected as for the best environmental variables that influenced the ecological factors at different areas. The most influential factors predicting the variations of total number of individuals recorded in different sampling seasons was salinity. Species richness of phytoplankton, zooplankton and benthos community was positively influenced by salinity and percentage of silt while it was negatively influenced by percentage of sand and the density of clay. Salinity, percentage of sand, slit, clay and water transparency showed higher contribution to explain the variance in species diversity in the present observations. It is assumed from the observation that the estuary has been polluted from domestic sewage, land washout, river run-off, shipping activities, industrial sewage.