[
    {
        "id": 207382,
        "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": 150,
        "title": "RAS-1975",
        "content_text": "BRIAN MORTON & P. S. WONG\n\npower. There is thus an advantage for an oyster farmer to possess a large family. Usually every member of the family participates in the work. Male members usually handle the more laborious procedures such as the laying of the cultch, the transfer of the oysters from one bed to the other and the harvesting of the oysters for resale. Female members may also participate in this work especially those young and strong enough--but more often they are in charge of separating the oysters from the cultch and the shucking and selling of the oysters. Younger members of the family assist with domestic chores.\n\nIn Deep Bay, the oysters are cultivated in the traditional manner i.e. by bottom-laying (*). This method involves the laying of cultch (*) on the muddy bottom to collect the oyster spat (#). The set oysters are then left to grow for one or two years in the breeding ground (*) before being transferred to the deeper fattening ground (†) for an additional period of one or more years prior to harvesting (#).\n\nElsewhere in the world various materials are used as cultch for the collection of spat. These include stones, shells, bamboo sticks (Cahn, 1950), lime coated roofing tiles or egg-crate fillers, cement dipped wood veneer rings or old fish nets (Needler, 1941; Quayle, 1969) and even sticks of the mangrove, Aegiceras majus (Roughley, 1922). In Hong Kong some ten years ago, rocks and shells (Plate 14; A, B) were most commonly used as cultch. The supply of rock from nearby shores has, however, been virtually exhausted. Consequently stones are now being replaced by concrete tiles (*) (Plate 14; C, D) or concrete posts (Plate 14; E, F). Stones and oyster shells of appropriate size and thickness are still collected and reserved as cultch whenever available. The oyster shells are first cleaned and placed in the sun for weathering prior to being used. Concrete slabs are made artificially at a cost of HK$500/10,000 (in 1974). Old concrete slabs or posts which remain unbroken after the oysters have been detached can be reused. They are cleaned to remove all fouling organisms and then dried in the sun.\n\nThe most important and labour intensive stage in the bottom-laying method of oyster culture is the collection of the spat (**). In Deep Bay oysters spawn from March to September when temperatures are high and salinities are low (Mok, 1973). As a consequence the cultch has to be laid within this period. However,\n\nPage 150\n\nPage 151",
        "txt_file_path": "txt/dfo323lmgvd/RAS-1975.txt",
        "external_url": "https://digitalrepository.lib.hku.hk/catalog/j0995146d",
        "rank": 0
    },
    {
        "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": 207389,
        "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": 157,
        "title": "RAS-1975",
        "content_text": "PACIFIC OYSTER INDUSTRY IN HONG KONG\n\n149\n\nMawatari, S. and T. Miyauchi, 1966. Studies for the improvement of Pearl oyster shell cleaning—1. Antifouling chemical coatings and their acceleration effect on shell growth. Miscellaneous Reports of the Research Institute for Natural Resources, Tokyo, 67; 54-66.\n\nMok, T. K., 1973. Studies on spawning and setting of the oyster in relation to seasonal environmental changes in Deep Bay, Hong Kong. Hong Kong Fisheries Bulletin, 3; 89-101.\n\nMok, T. K., 1974. Study of the feasibility of culturing the Deep Bay oyster Crassostrea gigas in Tung Chung Bay, Hong Kong. Hong Kong Fisheries Bulletin, 4 (in press).\n\nMorton, B. S., 1975. Pollution of Hong Kong's commercial oyster beds. Marine Pollution Bulletin, 6; 117-122.\n\nMorton, B. S. and K. F. Shortridge, 1976. Coliform bacteria levels correlated with the tidal cycle of feeding and digestion in the Pacific oyster (Crassostrea gigas) cultured in Deep Bay, Hong Kong. Malacological Review (in press).\n\nMorton, B. S. and R. S. S. Wu, 1975. The hydrology of the coastal waters of Hong Kong. Environmental Research, 10; 319-347.\n\nNeedler, A. W. H., 1941. Oyster farming in Eastern Canada. Bulletin of the Fisheries Research Board of Canada, 60; 1-83.\n\nQuayle, D. B., 1969. Pacific oyster culture in British Columbia. Bulletin of the Fisheries Research Board of Canada, 167; 1-68.\n\nRougley, T. C., 1922. Oyster culture on the George's River, New South Wales. Sydney, Technological Museum, Technical Education Series, 25.\n\nTschang, S., C. Y. Chi et al., 1962. Animals of Economic Importance of China. Marine molluscs. Scientific publisher, Peking.\n\n張靈,賽錄彥等,1962. 中國經濟動物誌,海産軟體動物. 科學出版社。\n\nWatts, J. C. D., 1973. Further observations on the hydrology of the Hong Kong territorial waters. Hong Kong Fisheries Bulletin, 3; 9-25.\n\nWong, P. S., 1975. The community associated with the Pacific oyster (Crassostrea gigas Thunberg) in Deep Bay, Hong Kong, with special reference to the shell borer Aspidopholas obtecta Sowerby. M.Phil. Thesis, University of Hong Kong.\n\nWood, P. C., 1969. The production of clean shellfish. Ministry of Agriculture, Fisheries and Food Laboratory Leaflet (New Series), 20; 1-16.\n\nYonge, C. M., 1960. Oysters. Collins, London.",
        "txt_file_path": "txt/dfo323lmgvd/RAS-1975.txt",
        "external_url": "https://digitalrepository.lib.hku.hk/catalog/j0995146d",
        "rank": 0
    },
    {
        "id": 214777,
        "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-1999",
        "page_number": 192,
        "title": "RAS-1999",
        "content_text": "A DECODED DIARY REVEALS A WAR TIME STORY\n\nP.J. ASTON\n\n157\n\nAbstract\n\nA diary written using a numerical code in a prisoner of war camp in 1941/2 should not be too difficult to decode, should it?\n\nHong Kong, 1941. On December 8 1941, the Japanese attacked Hong Kong. Seventeen days later, on Christmas day, the brave but outnumbered defending forces surrendered and were put into prisoner of war camps in which many died. A young squadron leader in the RAF, Donald Hill, kept a diary of events during the battle for Hong Kong and for a while during his captivity. In order to keep it secret, he wrote it in a numerical code which, according to the cover of the book in which he wrote, was supposedly \"Russel's Mathematical Tables\". Donald survived the camp and brought the diary out with him. However, his experiences were so traumatic that he did not like to talk about them. The diary was never translated before his death in 1985.\n\nGuildford, 1996. The phone rings again. The secretary in the Department of Mathematical and Computing Sciences, University of Surrey answers it, polite as always. The caller, Col Ian Quayle of the Soldiers, Sailors and Airmen's Families Association, asks to speak to a mathematician. Having just finished some photocopying, I happen to be the nearest person to the phone so the secretary asks if I will deal with the call. Col Quayle explains about Donald Hill's diary. Mrs Pamela Hill, Donald's widow, is keen to have the diary decoded so that she can find out more about a closed chapter in his life. I suggest that he sends a copy of the diary and say that I will have a look at it.\n\nThe Diary. The first page described how the 'Tables' could be used for multiplication. Instructions for multiplying 83 by 26 were given which could be followed on the first page of numbers. However, the claimed answer of 2118 was clearly incorrect. This presumably was part of the disguise.\n\nTwelve pages filled with numbers followed. On each page there",
        "txt_file_path": "txt/dfo323lmgvd/RAS-1999.txt",
        "external_url": "https://digitalrepository.lib.hku.hk/catalog/s178b887x",
        "rank": 0
    }
]