The Japanese government has decided to boost maritime monitoring spots ahead of the anticipated release of treated water from the damaged Fukushima Daiichi nuclear plant.

At the Fukushima Daiichi plant, water is used to cool molten nuclear fuel. It mixes with rain and groundwater that flows into damaged reactor buildings.

The water is treated to remove most of the radioactive materials, but still contains tritium and other radioactive substances.

The treated water will be discharged into the ocean after being diluted below government safety standards, starting in spring 2023.

The government discussed its plan to measure levels of radioactive substances in the seawater at a meeting of relevant ministries and agencies on Wednesday.

The government decided to increase its tritium monitoring locations by 42 to 54, within 300 meters to 50 kilometers of the released spot. It will also include fish in its monitoring.

It plans to adopt these enhancements this spring so that authorities can compare the water before and after release.

The government plans to make measurements four times per year, and increase frequency immediately after the release starts. It will report the results to an expert panel and seek its analysis and advice.

There have been lingering concerns mainly among local communities based on adverse rumors about the safety of the discharge into the ocean.

Environment Minister Yamaguchi Tsuyoshi said at Wednesday's meeting that monitoring is important for the reconstruction of regions affected by the 2011 earthquake and tsunami, which triggered the Fukushima Daiichi accident.

He pledged efforts to dispel unfounded rumors, saying that relevant organizations will work together to offer a sense of security to those who are worried by conducting objective, transparent and credible monitoring.