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ing the largest agricultural area of Hong Kong—the Yuen Long Plain (†). Deep Bay is sheltered and with the large amount of silt brought down partly from the rivers draining into the bay and partly from the Pearl River, the whole area is very shallow. The depth of water never exceeds 6 metres. Consequently, a large expanse of shore is exposed by the receding tide. The oysters are cultivated on this muddy intertidal flat (Plate 13).
The hydrology of Deep Bay has been studied by Bromhall (1958), and more recently and in greater detail by Mok (1973), Leung et al (1975) and Morton and Wu (1975). As elsewhere in Hong Kong, Deep Bay is influenced by the north-easterly monsoon in winter and the south-easterly monsoon in summer. In winter, from November to February, the cool, dry north-easterly monsoon lowers the water temperature to around 10–15°C and maintains the salinity at a high level of 26–32%. In summer, from June to August, the water temperature rapidly rises to approximately 28–32°C. The cooling and warming of Deep Bay is enhanced and hastened by the shallowness of the water. The warm, wet south-easterly monsoon in summer brings heavy rainfall to southern China, increasing the discharge of the Pearl River, the Shum Chun River, the Yuen Long Creek and other small streams entering the bay. An additional source of fresh water is the direct runoff from the land. The water in Deep Bay is therefore greatly diluted, with the salinity reduced to 5–10% in summer. Consequently, typically estuarine conditions prevail within the bay, and with the influx of freshwater, the water is highly productive (Watts, 1973; Leung et al, 1975). The cool saline water in winter and the warm, almost fresh water conditions in summer are particularly suitable for the cultivation of the Pacific oyster.
The area of Deep Bay, on the Hong Kong side, is divided into a number of T'ong or village family (#) plots—six being the most frequently quoted number. The oyster industry in Hong Kong is being run on a family basis, with neither a large capital investment nor special organised planning. Each oyster farmer may own or rent several acres of oyster beds. The essential equipment an oyster farmer must possess is a sampan (✯✯), a wooden sledge (AU), a pair of tongs (##) and a shucking hammer (1). A small sum of money may be needed to buy new cultch—the artificial substrate upon which the oyster spat settles. The most important factor regulating the organization of the industry is the availability of man-
PACIFIC OYSTER INDUSTRY IN HONG KONG
141
ing the largest agricultural area of Hong Kong-the Yuen Long Plain (†). Deep Bay is sheltered and with the large amount of silt brought down partly from the rivers draining into the bay and partly from the Pearl River, the whole area is very shallow. The depth of water never exceeds 6 metres. Consequently a large expanse of shore is exposed by the receeding tide. The oysters are cultivated on this muddy intertidal flat (Plate 13).
The hydrology of Deep Bay has been studied by Bromhall (1958), and more recently and in greater detail by Mok (1973), Leung et al (1975) and Morton and Wu (1975). As elsewhere in Hong Kong, Deep Bay is influenced by the north-easterly monsoon in winter and the south-easterly monsoon in summer. In winter from November to February the cool, dry north-easterly monsoon lowers the water temperature to around 10-15°C. and maintains the salinity at a high level of 26-32%. In summer from June to August the water temperature rapidly rises to approximately 28- 32°C. The cooling and warming of Deep Bay is enhanced and hastened by the shallowness of the water. The warm wet south- easterly monsoon in summer brings heavy rainfall to southern China increasing the discharge of the Pearl River, the Shum Chun River, the Yuen Long Creek and other small streams entering the bay. An additional source of fresh water is the direct runoff from the land. The water in Deep Bay is therefore greatly diluted with the salinity reduced to 5-10% in summer. Consequently typically estuarine conditions prevail within the bay and with the influx of freshwater the water is highly productive (Watts, 1973; Leung et al, 1975). The cool saline water in winter and the warm almost fresh water conditions in summer are particularly suitable for the cultiva- tion of the Pacific oyster.
The area of Deep Bay, on the Hong Kong side is divided into a number of T'ong or village family (#) plots-six being the most frequently quoted number. The oyster industry in Hong Kong is being run on a family basis with neither a large capital investment nor special organised planning. Each oyster farmer may own or rent several acres of oyster beds. The essential equipment an oyster farmer must possess is a sampan (✯✯), a wooden sledge (AU), a pair of tongs (##) and a shucking hammer (1). A small sum of money may be needed to buy new cultch-the artificial substrate upon which the oyster spat settles. The most important factor re- gulating the organization of the industry is the availability of man-
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