Recent decisions by two local fishing cooperatives to delay a resumption of fishing near the Fukushima nuclear plant highlight the confusion over ocean contamination. The cooperatives decided not to fish in the area because they have no hope of selling their catch, not because marine life in the area is unsafe to eat.

The decisions suggest it is the perception of a health risk not an actual health risk per se that is limiting fishing in the area. At the same time, a research team whose livelihood does not depend on fishing says there are still hotspots of contamination on the seabed in surrounding areas.

Safety concerns have also strengthened recently following leaks of contaminated water at the plant that its operator said could have reached the seawater enclosed by the plant's port. The latest leaks prompted South Korea to ban imports of marine products from the area.

Amid this ongoing uncertainty over the safety of produce from the seas around Fukushima, Japan's nuclear watchdog has decided to integrate existing monitoring efforts and present a clearer picture of the situation.

Since the Fukushima disaster in March 2011, several government organizations have sampled and checked seawater and seafood around the region in operations that have largely run independently of one another.