Fukushima fish riddled with radioactivity stokes fears about wastewater release plan

A black rockfish caught in the nuclear plant's port contained 18,000 becquerels per kilogram of radioactive cesium, 180 times over the legal safety limit.

A fish living near the Fukushima Daiichi nuclear plant that melted down in 2011 was found to contain astronomical levels of radioactive cesium, stoking fears about the Japanese government’s plan to release 1.3 million tonnes of treated wastewater from the plant in a matter of weeks.

The black rockfish contained 18,000 becquerels per kilogram of cesium-137 and was caught on May 18 in the inner breakwater of the plant’s port, the Guardian reported. Japan’s safety limit for radiation in food is 100 becquerels per kilogram, meaning the fish had a radioactive concentration 180 times over the legal limit.

In the past year, 44 fish with cesium levels above 100 becquerels per kilogram have been found in the Fukushima plant port. One specimen was an eel, found to have 1,700 becquerels per kilogram, and another was a rock trout, which measured at 1,200 becquerels per kilogram.

The fish were caught and tested by the operator of the Fukushima Daiichi nuclear plant, Tokyo Electric Power Company (TEPCO). The company has been testing fish off the plant’s port since the meltdown in March 2011, when a massive earthquake and tsunami destroyed the plant’s cooling system, causing three of its reactors to fail.

Water used to cool the reactor cores accumulated in about 1,000 tanks in the plant, and will reach their capacity by early 2024. Japanese officials say the water needs to be released to prevent accidental leaks in case of another disaster and to continue with the plant’s decommissioning.

The government plans to release the water over decades through an undersea tunnel, starting this summer, much to the dismay of neighbouring countries and local fishers.

When asked about concerns around the wastewater release plan, a TEPCO official told the Guardian that the “impact on the public and environment will be minuscule.”

According to the Associated Press, TEPCO attributes the high radioactivity in fish caught within the plant’s port to contaminated sediment from the initial nuclear meltdown, and continued run-off from rainwater that flows into the inner breakwater.