Tune Fishing pefore the initiation of the CASTLE series, and especially in connection with any deep underwater test that might be considered, it seemed to us that the impact of auch operations on tuna fishing would be a serious one. Consequently, some months back [ assigned this problem as a major concern to Or. Willis Re Boss of the ficlogy Branch of this Division. Dr. doas visited imiwetok, accelerated the construction and equipment of the Laboratory there, conferred with fisheries research people in Honolulu, augmented the level of our support there, and reviewed witn various Naval and fisheries groups on the vest Coast the provlems of tuna fishing and marketing in general. Tne tuna is a “ish that ranges widely in tropical anc temperate waters of the Pacific Ccean and is an important economic asset especially to Japan an the United States, including the Territory of Hawali. Six species are recognised, and there are some differences between those of the western waters and those of the castern Pacific. . Tagging experiments have show, however, that initivicual fish may travel great distances over a period of a few weeks. Tuna tagred off California nave been caugut as far away as the waters of Japan. The catch coming into the imited ‘tates is in nart from American fishermen operatiny iostly in eastern waters of tne Ocean, andfrom Japanese sources shipped from Japan either as frozen fish* or in cans.** Fisheries based in Hawaii are in general inadequate to mect the local demand both for immediate consumption and for packing for shipment to the United States, ami a considerabie amount of fish from Japanese sources is delivered to the Islands. Figures on the tuna catch for the years 1939 and 1951, by area and country, are shown in the attached table. The region of the Marshall Islands is not very oroductive of tuna fish, and only Japanese “ishermen bother to visit these waters. Prior to World War IT there was no fishiny of any consequence by the Japanese, although they themselves held these islands. Generally, fishing along the northern Marshalls is engaged in by ships going to or from the more productive areas to the south. * Frosen Tuna (1952) Japan exported to U.Sea.t Japan exported to Canada Total 45, 300,000 pounds of frozen tuna 5,736,000 pounds of frosen tuna 51,036,000 pounde of frozen tuna 1 We import 69 million pounds (1952)