A STUDY aimed at deciding how to protect fish in the territory's waters announced yesterday may have come too late to save vital breeding grounds, biologists warned. The government project will identify spawning and nursery areas and assess the impact of reclamation and pollution on Hong Kong's fish population. Experts welcomed the study but said it should have been done years ago, before reclamation began. Hong Kong University head of Ecology and Biodiversity Dr John Hodgkiss said: 'It's not before time. I hope it's not too late. 'We know very little about fish in Hong Kong waters, so what they're doing is wonderful, but it should have been done a long time ago.' Reclamation is carried out in shallow areas which are likely to be good nursery grounds for fish. Dredging disrupts areas of fine sand where fish can lay eggs and their young find food. Digging up large quantities of sand also leaves plumes of silt and sediment suspended in the water, which can affect spawning areas kilometres away. Dr Hodgkiss said: 'You can see coloured plumes in the water that have been carried for miles before settling. It can come down like rain and could land on eggs or a surface where fish feed.' Fish expert Dr Ni I-Hsun, of the Hong Kong University of Science and Technology, said: 'Although people in Hong Kong enjoy eating fish, the problem is we don't even know how many fish we have. There's only part one of a book published in 1968. 'The good thing is that at least the Government is starting to pay attention to this, but the bad thing is it's a bit too late. 'We should have done this in the very beginning before dredging and before reclamation started. 'Also, you have to monitor consistently. I would support long-term studies instead of a short-term project, but at least this is better than no project at all.' Dr Ni said he had so far identified about 200 species in local waters but suspected there were many more. The Agriculture and Fisheries Department, which has commissioned the $15 million study, admitted it should have been done earlier. But a spokesman said: 'It's better late than never. This will give us a baseline which will help us to protect sensitive areas in future.' Hong Kong fishermen catch about 211,000 tonnes of fish a year, but only 10 per cent now come from local waters.