On the Water Temperature and Direction of Current concerning the Fluctuation Catch of Mackerel in the Sea off Kagoshima.

On the mackerel fishing experiment in the sea off Isso and Satamisaki the following results were obtained. 1) Optimum temperature for fishing was from 21℃ to 25℃ in the case of large sized fish and from 26℃ to 28℃ in the case of small sized at the fishing ground of Isso, but in 22℃ at Satamisaki. 2) Difference between the water temperature of surface and of 30m depth was in 1.0℃～0.3℃ and good fishing was in 0.51℃. 3) The depth of fising changed by the water temperature, in spring and summer. When the surface temperature of water equaled to the optimum temperature of fishing, the depth of fishing became shallow, but in autumn never so. 4) The good fishing was in the current of NE～SE, but rhe small in NW～SW and S