Greenpeace said last Thursday it is sending its Rainbow Warrior flagship to Japan to test seawater and marine life near the tsunami-hit Fukushima nuclear plant which is leaking radiation.

The ship has left Taiwan and is set to start testing as early as next Wednesday, said the environmental activist group, which has also been monitoring aerial and soil radiation and food produce near the atomic plant.

Plant operator Tokyo Electric Power Co. (TEPCO) said last Thursday that some 520 tonnes of runoff which reached the sea from April1-6 through a crack in a storage pit had reached about 4,700 terabecquerels – 20,000 times above the plant’s legal annual limit.

TEPCO has also dumped 10,000 tonnes of lower-level radioactive water into the Pacific Ocean to free up storage space for more highly contaminated runoff that has resulted from weeks of emergency reactor dousing operations.

Greenpeace Japan executive director Junichi Sato said water testing was important because “Japan relies heavily on the ocean to feed itself.” “Given the continual leaking of radioactive water into the marine environment – including TEPCO’s release of huge quantities of contaminated water – it is critical that independent testing is undertaken, in order to assess the true extent of the contamination and the possible impacts on public health and the food web,” Sato said in a statement.

“We have informed Japan’s government and are currently working through the appropriate channels to ensure we can add marine research to the radiation monitoring already carried by our land-based teams in the Fukushima area.”