東支那海におけるシロカジキの漁場構成に関する研究-I

Abstract

There are two chief environmental factors, biological and non-biological, in the fishing-ground constitution of white marlin over the East China Sea; the former consists of the distribution of mackerel and horse-mackerel and the latter consists of the effect variations of Kuroshio-warm-current and the Continent-coastal cold water mass. And the white marlin migrates over to the East China Sea not in order to spawn but in order to feed mackerel and horse-mackerel etc. And as for its fishing ground, and in winter it covers the southern Kuroshio sea front which is adjoined to the mackerel fishing ground; and in spring and summer it removes, in accordance with the rise of the water-temperature, towards the central and northern sea front, which is overlapped with the mackerel fishing ground; and in autumn it removes, in accordance with the lowering of the water temperature, and along the mackerel fishing ground, towards southern sea front. And it is supposed that the constitution of the white marlin fishing ground is, so long as the white marlin may adapt itself to the sea conditions, apt to be subjected to the biological factors such as the distributions of mackerel and horse mackerel etc. rather than the sea conditions.