Japan has started discharging Fukushima nuclear wastewater, leading to China banning the import of Japanese seafood. This has had a wider impact than anticipated, affecting the prices of Japanese seafood, particularly high-value tuna, which has seen a more than two percent decline. China is Japan's largest seafood export market, and the ban has caused a significant loss for Japan, with the amount of imported Japanese seafood already decreasing before the discharge decision was made.