PW18 Field Biological Monitoring of Ecosystem Impairment
Exhibit Hall
8:00 AM - Wednesday
(PW274) Heavy metal contamination monitoring with Foraminifera south east coast of India.
NADIMIKERI, JAYARAJU1, 1 S.V.UNIVERSITY, S.V.UNIVERSITY, TIRUPATI, A P, INDIA
ABSTRACT- Disposal of sulphidic mine waste in marine environments constitutes an environmental risk due to a potential uptake and accumulation of heavy metals in biota. Bay sediments under the study are contaminated by lead and zinc as a result of mining activity and marine waste disposal over two decades. Four cores taken upto 10 km away from the disposal area, were collected in 2001. Analysis include radiochemical dating (210Pb), heavy metal concentration analysis (total and bioavailable fractions) and high-resolution foraminiferal stratigraphy. A two step change in foraminifera assemblage composition is observed. The first major change is presumably associated with oceanographic changes in the area over two decades ago, the second with the initiation of the miming in the early nineties. After the final closure of the mine, the opportunistic species, Stainforthia feylingi, which did not occur previously in the Bay immigrated the tailing disposal area (42 m water depth) together with a few other species (Elphidium excavatum, Cassidulina reniforme, Buccella frigida). The study shows a high correlation between the frequency of morphological abnormalities in the species Melonis barleeanus and bioavailable / total lead concentrations in core sections. This is used to evaluate spatial and temporal trends in the biological impacts due to anthropogenic heavy metals from the marine disposal. Upto 107 deformed specimens of M. barleeanus were found per 50 g sediment (equivalent to 19% of total number of specimens) in the area is about 4% for M. barleeanus, based on this study, it may be concluded that morphological abnormalities on foraminifera represent a useful biomarker for background studies and for evaluating long-term environmental impact and subsequent recovery.
Key words: Foraminifera, Contamination, Heavy Metals, Sediments