According to the prefectural Fisheries Experiment Station, the number of specimens tested in 2016 was 8,502. Among those, radioactive cesium was not detected (i.e., less than the detection limit value) in 8,080 specimens, or some 95.0 percent of the total. The last time that the reference value had been exceeded was in March 2015, after which no instances have been registered.

The inspections, which started in April 2011, include fish and shellfish taken from the sea within a 20-km radius from the Fukushima Daiichi site. The proportion of fish and shellfish exceeding the reference value has been decreasing year by year, as follows: 39.8 percent in 2011, 16.5 percent in 2012, 3.7 percent in 2013, 0.9 percent in 2014, and 0.05 percent in 2015.

Test operations are continuing in limited sea areas in the coastal waters off Fukushima, including fish species in which it is difficult to incorporate radioactive substances.