Japanese fisheries officials say there have been no major changes in the prices of fish landed at ports in Fukushima Prefecture after the release of treated and diluted water from the damaged nuclear power plant began.

Sunday marked one month since the Tokyo Electric Power Company began discharging the water from the Fukushima Daiichi plant into the ocean on August 24.

The Japan Fisheries Information Service Center surveyed the prices of stone flounders and flounders that were unloaded and auctioned at a port in Soma City, Fukushima Prefecture, from September 1 through 22.

The center says the average price of stone flounders was 1,501 yen, or about 10.1 dollars, per kilogram. This is roughly 4.3 dollars higher than the nationwide average.

The average price of flounders was around 12.7 dollars per kilogram, about 20 cents higher than the nationwide average.

Officials at a local fisheries cooperative in the city say that it is difficult to determine whether the water release has impacted the prices of fish, as such prices can change depending on size and freshness, as well as the volume of fish being landed at other ports.

They say they have not confirmed any reputational damage caused by the water release so far, as they see no major changes in the prices of local seafood.

The Fukushima Daiichi nuclear plant suffered a triple meltdown in the 2011 earthquake and tsunami. Water used to cool molten fuel at the plant has been mixing with rain and groundwater. The accumulated water is being treated to remove most radioactive substances, but still contains tritium.

Before releasing the treated water into the sea, the plant's operator dilutes it to reduce tritium levels to about one-seventh of the World Health Organization's guidelines for drinking water.