A search of markets for fish killed by red tide has instead revealed rotting fish on sale in northern areas of the New Territories, the Regional Services Department says. A spokesman said the fish showed no signs of being affected by the algae and might have simply been left on sale too long. No one was prosecuted over the rotting fish, although warnings were issued. The rotting fish were probably left over as a result of people being 'too scared' to buy them, Federation of Hong Kong Aquaculture Associations chairman Wong Yung-kun said. 'Those so-called experts give warnings every day against eating fish. It is natural people will not buy fish,' he said. 'We hope these experts find really substantive proof before making such claims. So far no one has fallen ill after eating fish.' The types of fish affected by red tide include: green garoupa; brown spotted garoupa; yellow garoupa; giant garoupa; purple amberjack; red sea bream; black sea bream; gold-lined sea bream; yellow croaker; Russell's snapper; red snapper; and pompano. Health Department tests carried out by Hong Kong University's Professor Daniel Chan Kwong-on on 60 fish and 10 shellfish from fish farms hit by red tide revealed six fish and three shellfish showed signs of contamination. But the contamination was low enough to render them safe to eat, a spokesman for the Health Department said. Yesterday, the Marine Department sent 51 vessels and 191 personnel to clean up the red tide at Tap Mun and Sai Kung, and at Lamma and Lantau islands. Regional Services Department trucks at Sam Mun Tsai and Wong Shek piers collected about 120 tonnes of waste. Swimmers were warned not to enter the water at South Bay yesterday. Meanwhile, 255 fishermen have registered with the Agriculture and Fisheries Department for emergency relief.