Shrimp farming, a lucrative export-oriented aquaculture activity, has often been written off as environmentally unfriendly. This has caused the shrimp industry major problems, jeopardising the existence of many a unit. To find out whether the allegations were valid or not, a field investigative study was conducted along the east coast by the Versova (Mumbai)-based Central Institute of Fisheries Education (CIFE).
The findings of this study clearly showed that the positive aspects of shrimp farming far outweighed the negative ones. Scientists from the institute have concluded that the development of shrimp culture is possible without any perceptible damage to the environment.
Information for the study was collected in May 1997 through proformas that were distributed to aqua-farmers, villagers, the general public, local state fisheries departments and representatives of other agencies concerned.
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First, the study dispelled the fear that agricultural land was being converted into prawn farms by the shrimp industry. Indeed, 85 per cent of the shrimp farms were observed to be located in the saline shore zone, which is unfit for agriculture. Only about 15 per cent of the farms had actually converted farm land into aquaculture ponds.
Revenue records showed otherwise because in coastal states all types of land, including unproductive land, is categorised as agricultural land. There is no provision for recording aqua-cultural land as a separate category.
The usual charge that mangrove areas were being put under shrimp cultivation has also been found to be baseless. In fact, experts say mangrove areas are unfit for commercial shrimp rearing because they have acid sulphate soils. The use of mangrove areas, therefore, is confined chiefly to traditional aquaculture practised by those who cannot afford to take up cost-intensive shrimp farming.
The results of the study also showed that apprehensions about large scale salinisation of land and drinking water in coastal areas due to shrimp farms were exaggerated. So were fears about pollution of sea and ground water due to effluent discharge from shrimp farms.
The salinisation of land and borewells used for drawing drinking water in the coastal belt was mostly attributed to the nearness of the sea and the frequent flushing by tidal brackish seawater. The study has provided examples showing that borewells dug in the middle of shrimp farms provided sweet and safe drinking water.
The discharge from shrimp farms have been found to be relatively harmless compared to the effluents that oil refineries, thermal plants, synthetic rubber and plastic manufacturing and even agricultural chemical units spew. This is because most of the pollutants in shrimp farm wastewater discharge are biodegradable; they consist of nitrogenous excretory products of shrimps and leftover feed. CIFE scientists feel wastewater management based on the guidelines drafted by fisheries experts and ecologists can reduce this problem even further.
Also, local populations did not complain of any health hazards from shrimp farming. Local people, in fact, were usually happy with the employment that these farms provided. Earlier, local labourers had to travel long distances in search of better employment. The shrimp farms offer jobs at relatively more favourable terms.
The only valid complaint was the obstruction of access to fishing areas by local fishermen. This was especially true in places where corporate houses have set up big farms of over 20 hectares. CIFE experts feel that this problem can be resolved if farm owners and fishing communities negotiated the issue constructively.