E Minamata disease Q&A

5. Mercury & Minamata Bay

Q2: How high is the mercury concentration in the fish currently caught in Minamata Bay?

A2: It has fallen to safe levels.

Very high levels (more than 10 ppm) of mercury used to be found in the fish from Minamata Bay: however, no fish have a mercury content that exceeds the provisional standards set by the national government (total mercury 0.4 ppm; methylmercury 0.3 ppm) at present, according to the monitoring done by Kumamoto Prefectural Government.
Therefore, the Governor of Kumamoto declared that the fish were safe in July 1997, and fishermen resumed fishing operations in Minamata Bay.