Conservationists are urging the government to introduce a licensing system for harvesting of shellfish around the coast amid fears that even the manual harvesting could damage the ecosystem. Concerns have been raised by the sight of fishermen going by boat to collect clams at Tai Pak Wan near Discovery Bay on Lantau. Eighteen reports were made to police from June 9 to September 9 but officers found no apparatus being used beyond some simple tools. Fishermen and local residents were taking the clams. The law allows harvesting of sea organisms outside the marine parks but prohibits the use of destructive equipment, such as suction and dredging devices, toxic substances and explosives. Catches are limited to between 30 and 100 catties, depending on the season. But World Wildlife Fund Hong Kong marine conservation officer Clarus Chu Ping-shing said the manual harvesting in Tai Pak Wan could damage the marine environment although it was less disruptive than mechanical harvesting. He said Hong Kong was one of the few regions in the world without a licence system to limit the collection of sea organisms. 'Most places in Asia, including the mainland, Japan and the Philippines have licence systems, not to mention European countries and the United States,' he said. The conservationist urged the government to introduce a licence system on sea organism exploitation as soon as possible. A spokeswoman for the Agriculture, Fisheries and Conservation Department said the government-appointed Committee on Sustainable Fisheries would consider a fishing licence system, among different options, for the sustainable development of the industry. She also said the department had taken joint actions in Tai Pak Wan and its vicinity with the marine police to prevent destructive fishing and that more operations were being arranged. Complaints arose at Tai Pak Wan as some residents were disturbed by the clam-collecting vessels when they used the beach, said a spokesman for Discovery Bay's management company. It has reported cases to the police and would continue to liaise with the police force in a bid to tackle the situation. Islands District Councillor Amy Yung Wing-sheung said such vessels had not been seen in recent days, although she herself witnessed a case and reported it to the police in August. A police spokesman said clam harvesting was usually seasonal, and that the activity started to tail off after mid-September every year.