Asked about concerns around the water discharge, the Tepco official reiterated that the company was confident “the impact on the public and environment will be minuscule”.
Rainwater from the areas around reactors one, two and three, which melted down during the March 2011 disaster, flows into the inner breakwater where the rockfish was caught in May. Cesium concentration in the sediment from the seabed in the inner breakwater measures more than 100,000 becquerels per kg, according to Tepco.
“Since contaminated water flowed into the Fukushima Daiichi nuclear power station port immediately after the accident, Tepco has periodically removed fish from inside the port since 2012 using fishnets that have been installed to prevent the fish from escaping the port,” a Tepco official told the Guardian.
A total of 44 fish with cesium levels above 100 becquerels per kg have been found in the Fukushima plant port between May 2022 and May 2023, Tepco confirmed, with 90% of those caught in or near the inner breakwater. Other specimens identified as having particularly high radioactivity were an eel with 1,700 becquerels per kg, caught in June 2022, and rock trout, with 1,200 becquerels in April 2023.