FOOD SAFETY, ENVIRONMENTAL HYGIENE, AGRICULTURE AND FISHERIES
diet enriched with vitamin C. Techniques for culturing high-finned grouper have been introduced to mariculturists at technical seminars. Two new freshwater fish species, jade perch and tench, have been identified as suitable for culture in Hong Kong waters, and have better market potential. Collaborative culture trials of these two species with fish farmers have been conducted.
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. Preliminary findings showed that the biofilters have led to the establishment of a rich fish community and a significant. reduction in organic waste in the sediments 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 began a trial scheme in recreational fishing on fish culture rafts in two fish culture zones in August 2002. Subsequently, the scheme has been extended to six more fish culture zones.
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.
Marketing
Much fresh food produce is sold in wholesale markets managed by the AFCD, the Vegetable Marketing Organisation and the Fish Marketing Organisation. The Western Wholesale Food Market and the Cheung Sha Wan Wholesale Food Market Phase I are the two biggest market complexes developed and managed by the department. Each is an integration of several markets. The Western Wholesale Food Market, for example, accommodates markets for freshwater fish, vegetables, fruit, poultry and eggs and allows buyers to purchase a variety of fresh food produce under one roof. Apart from these market complexes, the AFCD also manages two temporary wholesale markets, one in North District and the other in Cheung Sha Wan, for vegetables and poultry respectively.
During the year, the Government's wholesale markets handled 290 000 tonnes of vegetables, 63 000 tonnes of poultry, 35 000 tonnes of freshwater fish and fisheries products, 113 000 tonnes of fruit and 51 000 tonnes of eggs. The total value amounted to $4.2 billion.
The Vegetable Marketing Organisation is established as a non-governmental body providing vegetable wholesale marketing facilities. It operates a vegetable wholesale market at Cheung Sha Wan, set up under the Agricultural Products (Marketing) Ordinance on a non-profit-making basis. It charges commission on the vegetables sold and in return provides trading facilities, transport, accounting, and pesticides residue testing services to farmers and traders. Any surplus is ploughed back into the
187