Daigo Fukuryu-Maru

Daigo Fukuryu-Maru

The “Daigo Fukuryu Maru” is a wooden deep-sea tuna fishing boat based in Yaizu Port, Shizuoka Prefecture. It was exposed to radiation the hydrogen bomb test conducted by the United States in Bikini Atoll of the Marshall Island on March 1, 1954. While fishing in the sea 160 kilometers east of the hypocenter, a sudden flash could be seen to the west, and a detonating sound like an earthquake could be heard. Later, the 23 fishermen onboard were all explosed to radiation, after the radioactive fallout ("ashes of death") rained down upon them later.
After radiation levels of the ship's materials had fallen and safety was confirmed, the “Daigo Fukuryu Maru” was remodeled into a student training ship called the “Hayabusa Maru” and owned by the Tokyo University of Fisheries.


“Bravo,” the H-bomb detonated by the US in Bikini Atoll on March 1, 1954, had 1,000 the explosive power (15 megatons) of the atomic bomb dropped on Hiroshima. Fragments of coral broken by the explosion were brought up into the mushroom cloud, and became radioactive "ashes of death," which fell on the surrounding sea and islands, widely contaminating the ocean and the atmosphere.

Exposure of fishing vessels

Daigo Fukuryu Maru was not the only fishing vessel damaged by the test. Many vessels from all over Japan were in the area and were damaged. Up to the end of 1954, 856 Japanese vessels were recorded as having landed contaminated tuna. There is a possibility that many fishermen were exposed to radiation, but much is not clear including the impact on their health.

Suffering of the Marshall Islands

The Republic of the Marshall Islands is a country comprising of many atolls, in the mid-west Pacific region. The United States designated the Marshall Islands as a nuclear test site between 1946 and 1958, and carried out nuclear tests 67 times.
Tests were conducted at Bikini and Eniwetok Atolls, and it is thought that many atolls and islands were damaged by the tests, including these two. However, the United States Government only acknowledges damage caused to Bikini, Eniwetok, Rongelap and Utirik Atolls, and damage caused to areas other than these four are not recognized.
Health impacts have been observed in the Marshall Islands, including cancer and thyroid abnormalities, as well as stillbirths and children born with congenital disabilities. Moreover, it is still impossible for people from several atolls to return to their home islands.

Bikini Atoll Nuclear Test Site

Bikini Atoll was designated a World Heritage Site by UNESCO in July, 2010. According to UNESCO, “Bikini Atoll has conserved direct tangible evidence that is highly significant in conveying the power of the nuclear tests, i.e. the sunken ships sent to the bottom of the lagoon by the tests in 1946 and the gigantic Bravo crater. Equivalent to 7,000 times the force of the Hiroshima bomb, the tests had major consequences on the geology and natural environment of Bikini Atoll and on the health of those who were exposed to radiation. Through its history, the atoll symbolizes the dawn of the nuclear age, despite its paradoxical image of peace and of earthly paradise.” Inhabitants of Bikini Atoll are still not able to return.

Conservation of the Daigo Fukuryu Maru

The Daigo Fukuryu Maru was decommissioned in 1967 (at the time, named as the "Hayabusa Maru"). It was sold to a dismantler and abadoned in the garbage dump on reclaimed land at Yume no shima. Citizens learned of this situation, and launched a movement for the preservation of the Daigo Fukuryu Maru.
In June 1976, the Tokyo Metropolitan Government opened the Daigo Fukuryu Maru Exhibition Hall, exhibiting the vessel publicly.

The wooden ship, Daigo Fukuryu Maru

The Daigo Fukuryu Maru was constructed in 1947 at Koza Town in Wakayama Prefecture as a bonito fishing boat. It is a wooden vessel, with a length of 30m, height 15m, and width of 6m, and its weight is 140 tons.
The Daigo Fukuryu Maru is valuable as an example of a wooden vessel that engaged in deep-sea fishing during the era of food shortages in the aftermath of World War II.

“The Daigo Fukuryu Maru Incident” and “The Bikini Incident”

Our association uses the term "Bikini Incident" rather than "Daigo Fukuryu Maru Incident," as the Daigo Fukuryu Maru was not the only vessel damaged by the hydrogen testing at Bikini Atoll; in fact many ships were experienced by this. Nuclear testing in the Marshall Islands continued until 1958, and therefore the testing and its impacts must not be considered in a limited way.