This chapter focuses on the US thermonuclear tests in the Pacific and their influences on Japanese tuna fishermen between 1954 and 1963. Besides the well-known Daigo Fukuryu Maru [Lucky Dragon 5], many other tuna vessels were contaminated by radioactive fallout, but very little is known about who those fishermen were, where they came from, and why they needed to risk their lives to catch tuna. This chapter explores the complicated history and structure of the Japanese tuna fishing industry, and shows which part (and which people) of the multi-layered industry were the most vulnerable to radioactive contamination. It further examines why the victimized fishermen were invisible in the mainstream anti-nuclear movement in Japan, and shows the alternative ways in which they expressed their dissent.

Introduction

Japanese tuna fisheries date back to ancient times. Tuna bones have been excavated even in the remains of Jōmon period (12,000–13,000 years ago) villages. In the Japanese language, maguro—typically referring to bluefin tuna (hon-maguro), but also including bigeyes (mebachi), yellowfins (kiwada), and albacores (binchō) depending on the situation—are distinguished from katsuo (skipjacks), although all these species are often indiscriminately called tuna in English. This distinction is important because it is relevant to the theme of this chapter: who and what were affected by thermonuclear tests in the Pacific during the early Cold War era. Daigo Fukuryū Maru [Lucky Dragon 5] and other vessels contaminated by radioactive fallout were smaller tuna boats mostly targeting bluefins, but not skipjacks or albacores.

Skipjacks have traditionally been processed into katsuobushi, which is the dried fillet essential for various Japanese recipes as an ingredient in broth. Historical records show that it was produced as far back as the 8th century, but it was a luxury item until the early 20th century. Kochi and Wakayama Prefectures were famous producers of katsuobushi, and it was also produced in Yaizu (Shizuoka Prefecture), Kagoshima, Okinawa, and in the Japanese colonies and mandate islands. A historian of Taiwanese fisheries says that the colonial Japanese government encouraged the production of katsuobushi (as well as sōdabushi, a less expensive version made from different species of skipjack) in Taiwan, and 85 percent of the product was sent to Japan, while the remaining 15 percent was consumed in Taiwan.