Significance of Egg and Larval Surveys in the Studies of Population Dynamics of Fish
The Japanese sardine, Sardinops melanosticta (Temminck and Schlegel), used to be one of the most important species of fish for the Japanese coastal fisheries, the catch amounting to 1,586,000 tons in 1936. However, the catch has declined since then and reached a minimum of 155,000 tons in 1945 (Kurita and Tanaka, 1956). After the war the nationwide Cooperative Iwashi Resources Investigations1 was started in 1949 to investigate the decline of the catch and to obtain scientific information for resource management and fishing forecasting (Nakai et al., 1955). The Investigations consisted of three main elements: a survey of the catch and effort statistics, a shore-based statistical survey (length and age data, etc.) at the fishing ports, and a survey at sea for eggs, larvae and hydrographic data, etc. The first aspect was discontinued after 1951 when the Statistics and Survey Division of the Ministry of Agriculture and Forestry commenced a survey of catch and effort statistics under a new system.
KeywordsFishing Effort Filtration Efficiency Immature Fish Scomber Japonicus Japanese Sardine
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