According to a report by E&E News, the researchers said that they sampled popular seafood species taken from near the Fukushima plant and measured the concentrations of radioactive cesium in fish. Their analysis showed that cesium concentrations had either decreased to levels before the 2011 tsunami or to levels safe for consumption. The research also confirmed that fish species higher up the food chain are safe for consumption under Japanese health standards, but because contaminants tend to accumulate in larger carnivorous species, more time will be required for complete recovery. The research team warned that “these species still require another 6 to 14 years... to reach the pre-accident levels.”
These findings confirmed the claims of Japanese scientists, specifically the work done by Tokyo Electric Power Co. (TEPCO), Japan's Nuclear Regulation Authority and the Japan Fisheries Agency.
The study was conducted by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) and a laboratory at the University of Toulouse in France in collaboration with a Japanese scientist.