THE Mai Po marshes will be used as a prototype for a similar project in Thailand, according to Thai environmental policymakers who visited Hong Kong's largest nature reserve this week. Delegates from the Thai Royal Forest Department, here to swap ideas on wetland conservation with the World Wide Fund for Nature in Hong Kong (WWF), were so impressed with the reserve they decided they wanted one of their own. Director of the Department's Wildlife Conservation Division, Seri Vejaboosakorn, said: ''We have learnt a lot about conservation during our visit and I think the experiences at Mai Po can be put to use in Thailand. ''On our return we will propose a second Mai Po to the Thai Government in a bid to create a coastal park which will provide a new habitat for birds.'' Executive Director of WWF and the designer of the Mai Po marshes, David Melville, said he welcomed the move by the Thai Royal Forest Department. ''The idea is not to make a clone of the Mai Po marshes but to take ideas from the reserve and learn from the problems we encountered to create a similar project,'' he said. As well as providing another important stop-off for migrating birds, the reserve would also become another attraction for the growing number of ecotourists visiting Thailand. But despite scientists' fears that mass tourism will threaten the delicate forest ecology in Thailand, Mr Vejaboosakorn encouraged Hongkong people to continue visiting the country's national parks and wildlife sanctuaries. ''All the money taken in park fees is ploughed back into their upkeep and I believe these places should be kept open for nature lovers to enjoy,'' he said.