Abstract
By the radioactivity in the air and sea water caused by the US hydrogen bomb tests in the area of Bikini-Eniwetok Atolls,1954. The radioactivity contamination to fishes and fishing boats, were brought about. The observation of the actual state of the radioactivity around Bikini-Eniwetok Atolls was carried out aboard the survey boat “ Shunkotsu-maru”. The maximum radioactivity in sea water was 7025 cpm/l at 570 km west of Bikini and the influence of the radioactivity was recognized as far as about 2000 km from Bikini Atoll. Some oceanographic discussions on the horizontal as well as vertical distributions of the radioactivity in the sea are given.
