ハワイ諸島南方海域における海洋調査 VII

The oceanographic observations and the tuna fishing experiments in the southern region of the Hawaiian Islands were carried out in May 1984. The results are summarized as follows: 1) The mean values of temperature and salinity were about 26.0°C and 35.23% in the surface water, about 24.9°C and 35.34% in the subsurface saline water, and about 7.6°C and 34.14% in the subarctic intermediate water, respectively. 2) Salinity of the surface water being higher than usual was remarkable. It apparently suggests that the anticlockwise meso-scale vortex existed. 3) The highest catch of marlin was made on Nos. 1 and 5 hooks, and that of albacore on No. 3 hook. 4) The actual depths of Nos. 1 and 5 hooks ranged between 95 m and 115 m, Nos. 2 and 4 hooks between 100 m and 145 m, and No. 3 hook between 120 m and 205 m. 5) The good catches of marlin were estimated to be at the depths of 95 m-105 m or less and that of albacore 180 m-205 m or more. 6) The survey value was larger than the catenary value on No. 1 hook, while the former was smaller than the latter on Nos. 2 and 3 hooks. 7) Mean value of difference between the catenary and the survey values on each hook was-2.9 m on No. 1 hook, 20.6 m on No. 2 and 29.2 m on No. 3