The Thai government is planning to lift a ban on black tiger prawn farming in fresh-water zones of the central provinces. "Areas where shrimp farming is possible will be identified after a survey is conducted,' said Yuwaree Inna, director of the water quality division of the science, technology and environment ministry. The government had earlier banned shrimp farming in the central provinces, one of the country's most important rice production areas, apprehending that it would aggravate the problem of soil salinity. However, since the prawns are a major export item and earns large amount of foreign exchange, many farmers had defied the ban. "In a bid to have their activities legalised, shrimp farmers have presented to the government several environmental protection techniques,' Yuwaree said. According to the secretary-general of the office of environmental policy and planning, any decision would be based on a study jointly done by the members of the office, pollution control board, land development authority and fisheries department.