Spatial-Temporal variation of benthic-community in Gopalpur coastal sediment, East coast of India

The study on the macrobenthos of Gopalpur coast, Odisha, East coast of India was undertaken during January 2015 to December 2015. The environmental parameters, sediment characteristics and macrobenthic organisms were collected from 3 stations. The physico-chemical parameters with relation to benthic community structure were studied. The salinity and sediment texture were the most important parameter at Gopalpur coast controlled the distribution and community structure of benthos. The annual rainfall at Gopalpur varied from 001.4-230.7mm. The temperature, salinity, DO, BOD showed spatio-temporal variation. The air and water temperature of Gopalpur coast varied from 26 to 34.20C and 27.5 to 30.20C respectively. The pH of Gopalpur coast varied from 7.2 to 8.3. The percentage composition of sand, silt and clay were in a range of 81.71 to 98.83%, 1.04 to 12.22%, 0.13 to 6.07% respectively. The salinity of Gopalpur coast varied from 5.3 to 31.7 PSU. The concentration of dissolved oxygen varied from 5.4 to 7.2 ml/l. The Bio-chemical oxygen demand ranged from 1.3 to 2.3 ml/l. The diversity of macro benthos of Gopalpur coast varied from 3 to 7 groups belonging to 5 phyla and the population density varied from 550 to 1400 ind./m2 at different stations. In total 8 groups were recorded namely nematodes, polychaetes, decapods, gastropods, bivalves, amphipods, isopods and echinoderms. 30 species were observed under 4 groups, out of which 8 species belongs to decapods, 10 species belongs to gastropods, 11 species belongs to bivalves and only 1 species belongs to echinoderms. Benthic faunal assemblages showed almost similar pattern of distribution at station-I and II (exclusive marine), dominated by nematodes. The station-III (brackish water) was quite different from the station-I and II with different environment and environmental parameters and dominated by polychaetes. In overall observation at 3 stations of Gopalpur coast nematodes dominated in abundance with 9.43-81.82% followed by polychaetes (4.55-51.79%), decapods (0-23.81%), gastropods (0-16.98%), bivalves (0-13.11%), amphipods (0-12.50%) isopods (0-11.32%), and asteroids (0-3.33%). The main objective of the research is to provide a data base and information regarding benthic community structure and to assess the pollution load as it is one of the famous tourist spot of East coast of India.