Udayakumar, P; Dr.Ouseph, P P(Cochin University Of Science And Technology, July 19, 2012)
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Abstract:
The nearshore marine ecosystem is a dynamic environment impacted by
many activities, especially the coastal waters and sediments contiguous to major
urban areas. Although heavy metals are natural constituents of the marine
environment, inputs are considered to be conservative pollutants and are
potentially toxic, accumulate in the sediment, are bioconcentrated by organisms
and may cause health problems to humans via the food chain. A variety of
metals in trace amounts are essential for biological processes in all organisms,
but excessive levels can be detrimental by acting as enzyme inhibitors.
Discharge of industrial wastewater, agriculture runoff and untreated sewage
pose a particularly serious threat to the coastal environment of Kerala, but there
is a dearth of studies in documenting the contaminant metals. This study aimed
principally to assess such contamination by examining the results of heavy
metal (Cu, Pb, Cr, Ni, Zn, Cd and Hg) analysis in seawater, sediment and
benthic biota from a survey of five transects along the central and northern
coast of Kerala in 2008 covering a 10.0 km stretch of near shore environment in
each transect. Trophic transfer of metal contaminants from aquatic invertebrates
to its predators was also assessed, by employing a suitable benthic food chain
model in order to understand which all metals are undergoing biotransference
(transfer of metals from a food source to consumer).The study of present contamination levels will be useful for potential
environmental remediation and ecosystem restoration at contaminated sites and
provides a scientific basis for standards and protective measures for the coastal
waters and sediments. The usefulness of biomonitor proposed in this study
would allow identification of different bioavailable metals as well as provide an
assessment of the magnitude of metal contamination in the coastal marine
milieu. The increments in concentration of certain metals between the predator
and prey discerned through benthic food chain can be interpreted as evidence of
biotransference.
Description:
School of Environmental Studies
Cochin University of Science and Technology