CALCUTTA, Sept. 28. - The state government is set to prepare an action plan to help preserve the ecological balance in the east Calcutta wetlands. 

The wetlands, which include sewage-fed fisheries, cover an area of 12,500 hectares. They are the only one of their kind in the country. 

This is the first time a conservation action plan has been mooted for an urban wetland anywhere in the world. A field base survey, on which the management action plan will be based was submitted to the state government last week.  
A team, comprising several well-known environmentalists, ecologists, engineers and management experts from all over the country, will be set up to prepare the action plan, a state government official said. 

The action plan also proposes to work out a scheme to preserve the sewage-fed fisheries. The fisheries (bheris) clear the city's sewer water naturally. "If the bheris are closed, a sewage treatment plant, at an estimated cost of Rs 400 crore, will have to be installed in the city," the official said. 

There are 286 fisheries in East Calcutta which cover an area of 3232.27 hectares, the survey report stated. Twenty-two of these have become inoperative. But water from these fisheries have not been drained out. 

The fisheries fall under the jurisdiction of four police stations in South 24-Parganas - Bhangar, Bidhhannagar (south), Sonarpur and Tiljala.  

The fisheries produce about 10,915 tons of fish annually. Of this, about 6136 tons is produced by 46 bheris in south Bidhannagar police station area. These bheris are larger in size and better managed.  

The state government will assist both Indian and foreign students carry out research on wetlands, senior officials said. There are also plans afoot to promote the wetlands as a tourist attraction.  

This is the first time a list of existing fisheries in east Calcutta , along with their area, location and amount of fish produced annually, has been prepared. During the survey, it was found that 17,238 people work in these fisheries as labourers. The total population of the area is 61,000. Of this, 19,238 are literate.