Greenpeace: Japanese Government must immediately investigate seaweed contamination

Press release - May 12, 2011
Tokyo, Japan, 12 May 2011 – Greenpeace today urged the Japanese authorities to undertake comprehensive radiation testing of seaweed along the Fukushima coast, after initial results from marine radiation monitoring carried out by the international environmental organisation showed levels of contamination far beyond allowed limits.

Initial tests of the 22 seaweed samples collected by Greenpeace along the coast North and South of the crippled Fukushima Daiichi nuclear plant, and up to 65km out to sea by its flag ship Rainbow Warrior registered significantly high levels of radioactive contamination. Ten samples show levels over 10,000 Bq/kg, while the official safety limits for seaweed are 2,000 Bq/kg for Iodine-131 and 500 Bq/kg for Caesium-137 (1).

“From May 20, fishermen along the coast will begin harvesting seaweed for public consumption - our research indicates a significant risk that this seaweed will be highly contaminated,” said Ike Teuling, Greenpeace radiation expert. “As both TEPCO’s sediment samples (2) and our own preliminary research shows, radioactive contamination is accumulating in the marine ecosystem that provides Japan with a quarter of its seafood, yet the authorities are still doing the very little to protect public health.”

“For the coastal communities trying to rebuild lives and get back to work after the March 11 earthquake and tsunami, radioactive contamination of the marine food web is exacerbating an ongoing tragedy,” said Wakao Hanaoka, Greenpeace Japan Oceans Campaigner. “It is crucial that the government immediately undertakes a study of seaweed contamination off Fukushima to protect the health and safety of fishermen and consumers, and so full compensation is given to communities affected by this ongoing nuclear disaster.”

Greenpeace is now conducting detailed analysis of fish, seawater, and seaweed collected outside of Japan’s 12 mile territorial waters (3), as well as fish, shellfish and seaweed samples collected from the Fukushima coast. A selection of samples have been sent to independent laboratories for further analysis, full results are expected to be released next week.


Greg McNevin, Greenpeace International Communications, +81 80 3930 3341
Greenpeace International Press Desk Hotline, Amsterdam +31 20 7182470

Photography and video of radiation monitoring by the Rainbow Warrior are available:
Greenpeace International Picture Desk, , +31629001152
Greenpeace International Video Desk, , +31 207182133

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Google map of locations and radiation readings compiled by Greenpeace teams:

1) 2,000 Bq/kg is the official safety limit for radioactive iodine, 500 Bq/kg for radioactive caesium, see:

The Berthold Bequerel monitor detects the total radioactivity (Bq/kg) in various samples (water, sediment, food). It does not identify specific isotopes. Its detection limit is 10,000 Bq/l.

Of the 10 samples collected at sea by the Rainbow Warrior:
- 3 samples were above the detection limit of 10,000 Bq/l, corresponding with over 12,000 to 13,000 Bq/kg depending on the density of the sample
- 2 samples contained significant levels of radioactivity (2233 and 1530 Bq/kg)
- 2 samples contained low levels of radioactivity (109 and 102 Bq/kg)
- 3 samples were below the lower detection limit and could not be measured

Of the 12 samples collected along the Fukushima coast:
- 6 samples were above the detection limit of 10,000 Bq/l, corresponding with over 14,000 to 23,000 Bq/kg depending on the density of the sample
- 4 samples contained significant levels of radioactivity (986 to 11,291 Bq/kg)
- 2 samples contained low levels of radioactivity (123 and 177 Bq/kg)

2) TEPCO discovers radiation levels 100 to 1,000 times higher than normal in sediment from the Fukushima coast:

3) The Greenpeace research plan:

MOFA’s limited approval of the research application, which was presented through diplomatic channels by the Dutch authorities: