Fresh fish constitute one of Hong Kong's most important primary products. Productions from capture and culture fisheries in 2004 were estimated at about 167 540 tonnes and 3 720 tonnes respectively, with a total value of $1.7 billion.

The Hong Kong fishing fleet comprises some 4 330 vessels which are manned by around 9 770 local fishermen and 4 090 Mainland deckhands. The predominant fishing method is trawling, which accounted for 85 per cent of the catch, or 141 830 tonnes. Other fishing methods include lining, gill netting and purse-seining. The 167 540 tonne total fish catch had an estimated wholesale value of $1.6 billion. Discounting the catch landed or sold outside Hong Kong, some 60 000 tonnes of the catch were supplied for local consumption.

Under licence from the AFCD, 1 125 mariculturists operate in 26 designated fish culture zones. They supplied 1 540 tonnes of live marine fish valued at $79 million.

Freshwater and brackish water fish are cultured in fish ponds covering some 1 030 hectares, most of which are located in the north-western New Territories where they form part of the wetland system of conservation interest. With the increasing urbanisation of the New Territories, commercial fish pond production has gradually declined. Pond fish culture yielded some 1 980 tonnes, or 5 per cent, of freshwater fish for local consumption.

To promote sustainable development of the fishing industry and to conserve fisheries resources in Hong Kong waters, the AFCD continued to pursue a number of fisheries management and conservation measures and to strengthen enforcement against destructive fishing practices. Following the completion of the artificial reef deployment project in 2003, the AFCD initiated an underwater monitoring survey at the deployed artificial reefs at Hoi Ha Wan and Yan Chau Tong Marine Parks, Port Shelter and Long Harbour to assess their performance in enhancing and supporting fisheries populations. Over 220 species of fish, including many high-valued species such as groupers, breams, snappers and sweetlips, have been using the reefs for feeding, shelter and as spawning and nursery areas. The AFCD also conducted another trial on releasing fish fingerlings in Long Harbour, and Hoi Ha Wan and Yan Chau Tong Marine Parks to assess its effectiveness in enriching Hong Kong's marine resources. Moreover, the department continued to assist fishermen in developing offshore fishing and more environmentally friendly and cost-effective fishing techniques, and to cope with the annual fishing moratorium in the South China Sea enforced by the Mainland fisheries authorities through provision of technical support, liaison services and credit facilities.

With the aim of enhancing the sustainability of the local aquaculture industry, the AFCD conducts adaptive development studies and provides technical services to fish farmers. A fish health management programme is in place to help fish farmers minimise losses due to fish disease. Under the programme, departmental staff make regular visits to fish farms to educate farmers on measures to prevent and detect disease, and to provide a fish disease diagnostic service in case of an outbreak. Improved culture techniques and good management practices are also introduced to farmers through seminars, on-farm demonstrations and advisory leaflets.

Traditionally, marine cultured fish are fed with trash fish. In recent years, with the AFCD's support, an increasing number of marine fish farmers have switched to moist or dry pellet feed which reduces pollution and improves both feed efficiency and fish health.

To provide a wider choice of species for culture, the department is identifying new species with good market potential that can be recommended to farmers. Collaborative culture trials of two new freshwater fish species, jade perch and tench, with fish farmers were completed in 2004. As compared with tench, jade perch could achieve a higher growth rate in local pond condition with better market potential. Techniques for culturing the two species have been introduced to fish farmers at technical seminars.

To mitigate the impact of mariculture on the surrounding environment, the AFCD, in collaboration with the City University of Hong Kong, is conducting a study on using specially designed artificial reefs known as biofilters to provide a hard substratum for growing filter-feeders, such as green-lipped mussels, to trap and remove organic wastes, thereby improving the water quality. The trial biofilters were placed in the Kau Sai fish culture zone in 2002. The study findings showed that the biofilters have led to the establishment of a rich fish community and helped remove organic wastes and improve seabed environment within the fish culture zone. In response to a growing public demand for angling facilities and the wish of some mariculturists to open their fish rafts for recreational fishing, the AFCD continues to operate a scheme to allow mariculturists to carry out recreational fishing activities on fish culture rafts. Ten fish culture zones have been approved by the department to conduct such activities.

The department continues to implement its red tide monitoring and management measures with a view to minimising the impact of red tides on mariculture. The monitoring effort includes proactive phytoplankton monitoring before the formation of a red tide and rapid risk assessment of red tide incidents that are reported. A computerised system using Geographic Information System technology helps visualise the spatial and temporal distribution of red tides and provides a quick analysis of their development and movement. Red tide warnings are disseminated to mariculturists and the public through the red tide support groups set up in fish culture zones, press releases and the AFCD website.