PRIMARY PRODUCTION
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liners and gill-netters that operate on the continental shelf of the South China Sea between the Gulf of Tonkin and the East China Sea. The remaining 54 per cent of the vessels are less than 10 metres long, consisting primarily of gill-netters, hand-liners, purse-seiners and mariculture craft which operate in shallow coastal waters.
Trawling accounted for 79 per cent, or 166 500 tonnes, of marine fish landed in 1994. The total catch of live and fresh marine fish available for local consumption amounted to 84 170 tonnes, with an estimated wholesale value of $1,050 million.
Marine fish culture is practised within 26 designated fish culture zones, most of which are found around the coast of the eastern New Territories. Fish culture licences are issued by the Agriculture and Fisheries Department. At the year's end, there were 1 628 licensed mariculturists. Young fish are reared in cages suspended from buoyed rafts. Grouper, seabream and snapper are the most common culture species. This sector supplied 2 990 tonnes of live marine fish valued at $180 million during the year.
Freshwater fish are also cultured. Fish ponds covering 1 240 hectares are located in the New Territories, mostly around Yuen Long. Several different species of carp are cultured in the same pond, each with a different food requirement to maximise utilisation of the nutrients introduced. The land area devoted to fish ponds has gradually declined with the increasing urbanisation of the New Territories. During the year, pond culture yielded 5 500 tonnes, or 12 per cent, of freshwater fish for local consumption.
Fisheries Development
Development activity in the Agriculture and Fisheries Department focussed on countering the environmental impact of pollution and intensive infrastructural development on fisheries and aquaculture.
The inshore marine environment is under unprecedented pressure from large-scale dredging for marine fill, dumping of mud and reclamation of the dwindling heritage of shallow seas to enhance the supply of land. Besides reducing water quality, this also destroys extensive areas of seabed habitats that support the marine fauna and fisheries resource. To mitigate against such damage, the department has begun a fisheries habitat enhancement project. Since the successful deployment of the first experimental artificial reef in late 1993, work has been underway to examine the potential benefits of deploying artificial reefs and enhancing the types of marine habitat favoured by commercial fish. Over the next few years, a variety of artificial habitats will be introduced over a significant area to help rehabilitate damaged seabeds, protect sensitive nursery areas and increase fish production.
Aquaculture studies are directed towards the development of more efficient culture systems and improved husbandry techniques to increase productivity and minimise the impact on the environment. A moist pellet preparation which substantially reduces pollution due to wastage and leacheate, and increases nutritional value was introduced to mariculturists to replace trash fish as feed. The feasibility of open sea cage culture is being explored with a view to introducing marine fish culture to more exposed coastal waters. Studies on the marine environment are conducted to assess the impact of pollution and red tides on fisheries, particularly mariculture operations, to help the industry minimise production loss. Low interest loans, administered by the department, are available to the aquaculture industry from the Kadoorie Agricultural Aid Loan Fund.