Anthropogenic Impact on the Pulicat Lagoon Monitoring with Foraminifera, East coast of India

Coastal lagoons are well investigated areas because of their economical and ecological importance. Pulicat Lagoon system which is a store house of all resources is under great threat following the anthropogenic pollution. This complex lagoon ecosystem’s surface area is about 500 sq.kms. In spite of the System’s conservation statutes its structure has been degenerating rapidly because of pressures fishing, tourism and agricultural activities. Fishing production of Pulicat Lagoon System is approximately 52 tons/ha/year. Although a serious fishery pressure has been determined in the area, according to mortality rate and age compositions, it has been found that the growth of marine life in the environment is in unhealthy condition. The date show that land based and atmospheric sources account about two-thirds of the total impact of contaminants in to the marine lagoon constituting 44 % and 33 % respectively. A total of 30 sediment samples were collected with in the depth zone of 5 fathoms from the lagoon. The study yielded 50 benthic foraminiferal species belongs to 24 genera, 16familys, 8 super families and 3 sub-orders. Variations are also reflected on the foraminiferal test morphology, diversity and distribution. A high percentage of foraminifers almost exclusively Ammonia have damaged shells with a few channels to entire whorl missing. The phenomenon is stress response to the anthropogenic pollution. The Ammonia-Elphidium assemblage is dominant in all stations followed by Spiroloculina –Bolivina assemblage.Suggestions for development of the lagoon management and maximum sustainable marine life production have been offered by determining the present lagoon management and some a biotic characteristics of this ecosystem. Many studies assume or conclude that foraminiferal assemblages and the frequency of deformed tests are proxy indicators of pollution, but others present confounding results. Under studying the complexity of anthropogenic pollution, coastal waters and sediment is critical to the design and interpretation of meaningful studies.