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

Sundara Raja Reddy B C,Reddy K R,Jayaraju N

doi:10.5923/j.ms.20120205.05

Abstract

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 ecosystemâs surface area is about 500 sq.kms. In spite of the Systemâs 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 âBolivina 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.

Highlights

The study area, is located in the Survey of India toposheets nos: 66 B/2, 66 B/3, 66 C/2 respectively at the scale of 1: 50,000
The lake is marked by steeply rising ridges, having a height of about 17m from the mean sea level (MSL) and composed of Quartzites of Cuddapah Super group (Proterozoic)[1]
This, monitoring and assessment of the risks to coastal ecosystems associated with heavy metal pollution are highly complex problems that require interdisciplinary teams with expertise in biology and ecology of lagoonal biotas[10]

Summary

Introduction

The study area, is located in the Survey of India toposheets nos: 66 B/2, 66 B/3, 66 C/2 respectively at the scale of 1: 50,000. The study area lies between longitudes 80o 02’ – 80o 20’ E and latitudes 13o22’-13o 45’ N (Fig.). The lake is marked by steeply rising ridges, having a height of about 17m from the mean sea level (MSL) and composed of Quartzites of Cuddapah Super group (Proterozoic)[1]. The steep and plain topography is due to the great difference in age between the Archean of the plain country and the Proterozoic of the high lands and due to the greater resistance for erosion offered by quartzites compared to gneisses. The important ephemeral rivers that join the lake include Arani and Kalangi (Fig.1)[2].

Methods

Results

Conclusion