COASTAL AQUACULTURE
Coastal aquaculture is one among the age old avocations of man. The Romans and the Japanese are known to have practiced oyster culture in its primitive form for several centuries and the South-East Asian countries have been carrying out fish culture for at least five centuries now. While the developed countries/ where aquaculture was started in recent times, have far advanced in the field with sophisticated technology, in the few developing countries, including India, which have traditional forms of aquaculture, it still remains at subsistence level, almost as it was in the distant past. But the recent developments in coastal aquaculture in this region signify the beginning of a new era in fisheries development with a thrust on the culture fisheries.
TRADITIONAL COASTAL AQUACULTURE IN INDIA
The traditional coastal aquaculture system of India is represented by the 'pokkali' fields of Kerala, bheries of West Bengal, 'gazani' farms of Karnataka and 'khazan' lands of Goa. These are natural systems operated with the tidal resources of water as well as organisms. About 5120 ha of low-lying coastal areas in Kerala are utilized for growing a salinity-tolerant variety of paddy called 'pokkali' during the south-west monsoon season and prawns during the rest of the year. Besides the seasonal fields, there are perennial fields where prawn farming is done throughout the year. The estimated production in paddy-cum-prawn culture varies from 500 to 1200 kg of prawns per hectare for six months period. The total production from these fields is around 4800 tonnes. The 'gazani' farms of Karnataka have a total spread of about 2320 ha mainly in the North Kanara district. In the brackish water areas nearer to the coast, prawn/fish culture is carried out along with salt production, while in the interior areas, paddy-cum-fish culture is practiced. The total production in these farms amount to about 600 tonnes of which 65% is constituted by prawns.
In Goa, prawn culture is done in the 'khazan' lands extending over an area of 1800 ha. Khariff crop of paddy is grown in the fields and after its harvest, the supply canals, as well as the fields in some cases, are used for culturing prawns. In West Bengal, the 'bheries' extending over an area of about 20.000 hectares in the Hooghly-Matlah estuarine system are used for the culture of fish and prawns. The production rate in these fields is around 300 kg/ha/annum.
Source: http://eprints.cmfri.org.in