A CASE STUDY ON THE IMPACT OF INDUSTRIAL EFFLUENT DISPOSAL ON THE FISHERY OF AMBA RIVER ESTUARY, MAHARASHTRA
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Authors
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S. N. GAJBHIYE
Regional Centre, National Institute of Oceanography, Sea shell,
7-Bungalows, Versova, Mumbai-400 061.
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PRATIK MEHTA
Regional Centre, National Institute of Oceanography, Sea shell,
7-Bungalows, Versova, Mumbai-400 061.
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S. MUSTAFA
Regional Centre, National Institute of Oceanography, Sea shell,
7-Bungalows, Versova, Mumbai-400 061.
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VIJAYALAKSHMI R. NAIR
Regional Centre, National Institute of Oceanography, Sea shell,
7-Bungalows, Versova, Mumbai-400 061.
Abstract
The impact of waste discharge on fishery resources IS a n1.atter of
great concern. The accepted norm in all environmental impact assessment
studies is to avoid areas of high fishery potential while locating a marine
outfall. Contemplating on this aspect a case study was conducted in the
Amba River estuary before and after the establishment of a petrochemical
complex at Nagothane. The treated wastewater from this complex is
released through a subsurface outfall after adopting effective control
measures for marine disposal of waste. Experimental trawling was done
at five locations covering a distance of 30 km during 1990 to 1991. The
catch rate within the estuary varied from 0.6 to 255 kg/h (av 24 kg/h). The
trend indicated considerable decrease in fishery potential from the mouth
of the estuary (av 64 kg/h) to the upstream location (av 11 kg/h). A total
of 49 species of fishes, 16 species of prawns, 7 species of crabs and 1
species of lobster were identified from the collections. Nu:mber of species
gradually increased from the interior segment at Dharamtar (8) to the
outer area near Revas (18). A comparison of the quantitative and
qualitative nature of the post outfall and preoutfall data revealed only
marginal difference. The study indicates that if necessary precautions
are taken to render the waste harmless the n1arine ecology will hardly be
affected.
