Community structure of meiobenthic nematodes was studied in 4 stations of Poonthura estuary. Maximum values of species diversity index coincided with the presence of maximum number of species. Moderate diversity, richness and evenness indices were observed at all stations due to low density of meiobenthos in the estuary. The community indices showed the minimum values during monsoon season coinciding with a fall in density. Notable changes in community structure were associated with organic enrichment. A decrease in abundance as well as species diversity and an increase in species dominance were recorded at the station close to sewage outfall.

community structure, nematodes, pollution, estuary