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Thursday, 21 April 2011

PETROCHEMICALS INDUSTRIES affects the coral reef biodiversity in Gulf of Kachchh

The main threats to the ecosystem of the Gulf of Kachchh are from oil, petrochemicals and allied industries. The Gulf area is being aggressively developed as oil importing bases because of its proximity to the oil exporting countries of the Middle East. The coastal oil and refinery facilities, as at present, are: Crude Oil Terminal at Vadinar and the Salaya-Mathura pipeline of Indian Oil Corporation and Relience Petroleum at Moti Khavdi. These two industries targeted to process together 39 million tonnes (MT) of crude oil per annum. Reliance along handled a traffic volume amounting to 19.8 MT in 1999-2000. The planned Vadinar-Bina overland pipeline of Bharat Petroleum and the sub-sea pipeline of Bharat-Oman Petroleum near Narara, the proposed Vadinar-Kandla submarine products pipeline, and the Kandla-Karnal cross country products pipeline are major threat in future. All these are being established in the inner-half of the Gulf. Six single buoy moorings (SBM) will be ultimately permitted to be located in the Gulf. As of 1999, 4 SBMs are in place and the remaining two are under consideration. These are being used to import up to 80 MT yr-1 crude oil per year through the facilities on the coast. The import is targeted to be increased gradually to 100 MT yr-1. During operation each SBM is allowed to release an average of 300 barrels (41 tons) of oil per year to the sea, as estimated by the Environment Protection Agency (EPA) of USA in 1978 for all offshore oil terminals in US waters. These figures were for the second generation SBMs. The present fourth generation SBMs has no permission to release any crude oil to the Gulf, although minor oil spills are reported. All these activities will be either close to or inside the MPA, which has been notified to protect and preserve the fragile ecosystem, particularly the live inter-tidal and sub-tidal coral reefs of the Gulf. One moderate or major accidental oil spill at sea or on land will be enough to destroy, almost irreversibly, the fragile coral reefs and their associate lush flora and fauna. It is believed, as of 1999, that several small oil spills have already taken place in the Gulf and have not been reported to any official agency. It seems that it was like a free for all to discharge pollution in the Gulf. Anybody could do anything and could get away with it, and/or created avoidable confusion afterwards. A few oil spills during late 1999 were, however, detected. Being small their ecological damages were insignificant. But their sources could not be identified beyond suspicion. In 1992-93, spilled oil was deposited on mangrove area at Pirotan and oil cake was formed over the surface. Mangroves in area of about 3 ha died and a thick layer of the oil cake over mudflats did not allowed regeneration for quite some times. Layer of oil cakes mixed with sands was recorded on the bets but these were not documented properly. In absence of surveillance and monitoring, these minor spills were not recorded but minor spills occurred undoubtedly in the past It should be borne in mind that, immediately after a spill, oil spreads out on the sea surface at a rate of 3 percent of the prevailing wind speed at 15o to the right of the wind direction in the northern hemisphere (Sen Gupta et al., 1993). Having lower surface tension than seawater oil will spread faster than the flow of water under it. The lighter fraction of oil, carbon numbers less than 12 C, comprising around 40%, will evaporate during the 24 hours immediately after a spill. Photo-oxidation by solar UV radiation will account for a maximum of 1% per day of the total volume spilled. The heavier fraction will be broken down by oil-degradation bacteria, naturally occurring in seawater, the maximum possible rate for which is 2 g.m-2.d-1. A part of the oil will also be oxidized by the dissolved oxygen at the rate of 1mg oil/ 3 mg O2. Barely 1% of the spilled oil may get dispersed, suspended or dissolved in water. All these processes proceed quite fast in warm waters. One can, therefore, optimistically, presume that in warm tropical waters roughly half of the spilled oil will disappear during the first 24 hours after a spill. Of course, this amount will vary with the varying density of oil at its source and the amb! ient temperature of the atmosphere and the sea. After the first 24 hours, owing to the sea state and high temperature, water-in-oil mousse may be formed, due to the prevailing wind which will adsorb onto the surface of any suspended particle to form tar balls. Some of the tar balls may sink to the seabed. The remaining tar balls will ultimately, be washed ashore on nearby beaches. In the Gulf of Kachchh, spilled oil will spread on the surface very fast due to the prevailing strong tidal currents over a large area and will become thinner and thinner at it spreads. Thus, even a spill of 15-20 tons will appear to be a 'huge' spill in satellite imagery. Therefore, the response time to tackle a spill in the Gulf will be limited to a few hours. But the natural decay evaporation, oxidation will be pretty fast. Sinking tar balls will be extremely harmful to the long coral polyps. These are constantly under stress due to siltation and sinking tar balls, if they fall on the polyps, may choke them and may prove to be fetal. Similar fate may befall the polyps if the spill is dispersed by spraying chemical dispersants, which will generate a large number of sinking water-in-oil mousse-like globules. Under the present policy, India is expected to attract greater foreign direct investment in the refinery sector, mostly because of technological progress changing the cost implications. India has now mastered almost all the tricks of the trade of setting up grass-root and other classes of refineries as well as running them profitably. We have perhaps, some of the lowest cost refineries in the world. Consequently India could become a net exporter of petroleum products in the early part of the next century and a swing producer to establish global products market. The fact that the State has geographical advantage for establishing this type of industry is already reflected in the recent pattern of investment. As stated under 'threats' the State will surely be facing increasing environmental stress from the petroleum group of industries.
 Ref. 'The MNP S in the GOK- a comprehensive study of the bio-diversity and management issues' GEER FOUNDATION, Gandhinagar

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