[
    {
        "id": 207387,
        "series_id": 26,
        "series_slug": "histsyn-rashkb-journal-engine",
        "series_title": "RASHKB Journal 皇家亞洲學會香港分會學刊",
        "series_use_hku_proxy": false,
        "document_key": "RAS-1975",
        "page_number": 155,
        "title": "RAS-1975",
        "content_text": "PACIFIC OYSTER INDUSTRY IN HONG KONG\n\n147\n\nBromhall (1958) reported upon an experiment using raft culture (*) in Deep Bay and showed that the oysters reached marketable size in two and a half years instead of four. Furukawa (1968) in a review of Japanese oyster culture reports that the raft method of culture has now virtually replaced all other methods of shellfish culture in that country, and that by this method the annual production of oysters has increased enormously, for example in Hiroshima. According to Quayle (1969) in his study of Pacific oyster culture in British Columbia, this method of culture is the most efficient with regard to the intensity of spatfalls and the subsequent growth and survival of the oyster. By this method, the culture of oyster is no longer limited to the shore and can be extended to deeper waters, thereby increasing the area available for culture. Recently conducted experiments undertaken by the Agricultural and Fisheries Department of the Hong Kong Government designed to test the feasibility of extending the oyster industry to the north side of Lantao Island (*) (Fig. 1) have been successful (Mok, 1974). The oysters are able to breed naturally in these waters and the reported growth rate is even faster; the oysters requiring only two years to reach marketable size. Oysters suspended in the water can utilise the whole column of water thereby reducing intraspecific competition. Moreover bottom living predators cannot attack the suspended oysters. In addition the large number of spat collected by this method can be separated from the cultch after one year and cultivated on trays, thereby solving the problem of overcrowding.\n\nRaft culture involves a similar amount of labour as that used in bottom-laying but the more arduous and unpleasant aspects of the work (i.e. the laying of the cultch on the muddy sea bed) are avoided. The strings of cultch to be suspended from the rafts can be prepared on land beforehand. During harvesting the strings of oysters can be hauled up from the raft into a boat, which is much easier than diving or tonging as is practised in Deep Bay. The advantage to such a system are many and obvious and result in larger spatfalls, a faster rate of growth, better quality of the flesh, reduced mortality and easier management. Since the surface waters of Deep Bay are less polluted (Leung et al., 1975), the oysters too would be safer to eat.\n\nThe increased intensity of fouling upon the strings is a problem but has been solved, for Pearl oysters at least (Mawatari and Miyau-",
        "txt_file_path": "txt/dfo323lmgvd/RAS-1975.txt",
        "external_url": "https://digitalrepository.lib.hku.hk/catalog/j0995146d",
        "rank": 0
    },
    {
        "id": 207388,
        "series_id": 26,
        "series_slug": "histsyn-rashkb-journal-engine",
        "series_title": "RASHKB Journal 皇家亞洲學會香港分會學刊",
        "series_use_hku_proxy": false,
        "document_key": "RAS-1975",
        "page_number": 156,
        "title": "RAS-1975",
        "content_text": "148\n\nBRIAN MORTON & P. S. WONG\n\nchi, 1966) by the application of anti-fouling paints. Undoubtedly the main disadvantage to this technique is that a large capital investment is required with high maintenance costs and a greater chance of damage and loss during a typhoon. As noted earlier oyster culture in Deep Bay is at present being run on a family basis lacking a large capital investment. The adoption of the more expensive raft method of culture would appear, under present socio-economic conditions, to be impossible. The setting up of a co-operative system by the oyster farmers concerned, together with an extension of the Government loan scheme for fisheries development to the oyster industry could enable the oyster farmers to obtain the necessary finance to improve the industry. With an available source of funds for investment and with further detailed research to determine the modifications required to ensure the success of a programme of modernisation in the special environment of Deep Bay, Hong Kong's oyster industry is not without a future.\n\nLITERATURE CITED\n\nBardach, J. E. and J. H. Ryther, 1968.\n\nThe Status and Potential of Aquaculture. American Institute of Biological Science, Washington, D.C. Vol. I (261pp.), Vol. II (224pp.).\n\nBromhall, J. D., 1958. On the biology and culture of the native oyster of Deep Bay, Hong Kong, Crassostrea sp. Hong Kong University Fisheries Journal, 2; 93-107.\n\nCahn, A. R., 1950. Oyster culture in Japan. The United States Fisheries and Wildlife Services Fisheries Leaflet, 383; 1-80.\n\nFurukawa, Atsushi, 1968. The raft method of oyster culture in Japan. In: Proceedings of the Oyster Culture Workshop (Ed. T. L. Linton). Marine Fisheries Division, Georgia Game and Fish Commission, Brunswick, Georgia, pp. 49-54.\n\nHong Kong Annual Departmental Report by the Director of Agriculture and Fisheries, 1953-54 to 1973-74. The Hong Kong Government.\n\nKnight-Jones, E. W., 1952. Reproduction of oysters in the rivers Crouch and Roach, Essex during 1947, 1948, 1949. Fishery Investigations, London, 18; 1-48.\n\nKorringa, P., 1947. Relations between the moon and periodicity in the breeding of animals. Ecological Monographs, 17; 347-381.\n\nLeung, C., B. S. Morton, K. F. Shortridge and P. S. Wong, 1975. The seasonal incidence of faecal bacteria in the tissues of the commercial oyster Crassostrea gigas Thunberg 1793 correlated with the hydrology of Deep Bay, Hong Kong. Proceedings of the Pacific Science Association Special Symposium in Marine Science, Hong Kong 1973; 114-127.",
        "txt_file_path": "txt/dfo323lmgvd/RAS-1975.txt",
        "external_url": "https://digitalrepository.lib.hku.hk/catalog/j0995146d",
        "rank": 0
    }
]