サバ群の行動とその要因について-II : 石狩湾におけるサバ群の浮上と環境要因

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This report deals with the relationship between the floating-up of mackerel shoals in-habiting the Bay of Ishikari, Hokkaido, from late in June to early in August, and the envi-ronmental factors such as the activity of the sun, direction of the wind, age of the moon and others. Originally the behavior of the fish has an immediate connection with the activity of the sun. The floating-up of the fish to the sea surface is carried out in the day-time. It is re-gularly intermittent by a certain periodicity, which being half as long as the period of sun-spots (about 13 days). It is very interesting to note that the periodicity does not necessarily take place in the same day every year. In the leap year it occurs about two days latter, but in the common year one day earlier than in the previous year. Second, there is a tendence that the fish shoals do not float near the sea surface, when the wind blows from the land to the offing in a whole day. The activity of mackerel sheals, however, has nothing to do with other meteorological factors, age of moon, rain and rough weather.
公益社団法人日本水産学会の論文