In recent years fish farming has declined in Hong Kong. In 1992 there were 1,620 hectares of fish ponds, 270 hectares of which were abandoned.
Ponds in the Deep Bay Buffer Zones accounted for about 71 per cent or 1,165 hectares.
The filling in of fish ponds around Deep Bay for the development of Fairview Park, Tin Shui Wai New Town, Wo Sang Wai, Palm Springs and Yuen Long Industrial Estate has reduced the fish pond area by over 600 hectares.
Construction of main drainage channels for Yuen Long and Kam Tin (over 140 hectares), construction of Route 3 in the Northwest New Territories (about 30 hectares) and Ngau Tam Mei's main drainage (20 hectares) will take a further toll. There has also been unauthorised filling in of fish ponds for container storage and car dump yards. Income Fluctuation of Fish Farming: There are many uncertainties in operating fish ponds. For example, crowded conditions in the ponds will prompt disease among the fish.
However, the most serious problem is the control of water conditions such as inadequate oxygen, excessive salinity and pH fluctuations, all of which can affect fish growth.
Also, the supply of live freshwater fish from China is responsible for depressed local wholesale prices.