SCIENTISTS fear Sham Chung and its ecological treasures will be destroyed and plundered by villagers and fish fanciers seeking a lucrative catch. Three Fathoms Cove, one of only five sites in the world where the black paradise fish is found, lacks protection because it is privately owned. Freshwater wetlands - often privately owned former agricultural land - are among the most threatened habitats due to increasing urbanisation. A survey of 28 wetlands, commissioned by the Agriculture and Fisheries Department, aims to identify the richest areas and recommend measures to protect them. Hong Kong University Department of Ecology and Biodiversity reader Dr David Dudgeon, who carried out the survey, said the research could prove a poisoned chalice for the rarities it reveals. News of the black paradise fish could lead to a flood of foreign collectors plundering streams, perhaps using destructive fishing practices, to catch the rare species. 'Believe me, the tropical fish industry looks at primary scientific literature,' Dr Dudgeon said. 'It would be worthwhile for a European hobbyist to come here and stay in a marsh and get a few thousand extremely rare fish which no one had caught in the wild before.' Another threat is villagers who see ecological discoveries as an obstacle to development - and try to damage the site and destroy its rarities. In January, villagers bulldozed dragonfly-rich streams at Sha Lo Tung - the site of a proposed residential development - just before it was due to be declared a Site of Special Scientific Interest. Dr Dudgeon said the same thing could happen at Sham Chung. 'It is possible people would go out to poison the marsh,' he said. Agriculture and Fisheries Department senior conservation officer Lay Chik-chuen said villagers had a right to cultivate their land.