Photo/Illutration Tokyo Electric Power Co. begins discharging treated radioactive water from its Fukushima No. 1 nuclear power plant on Aug. 24. (Takeshi Iwashita)

Japan’s fisheries agency said fish caught in waters around the crippled Fukushima No. 1 nuclear power plant complex did not contain detectable levels of the radioactive isotope tritium.

The Aug. 26 announcement came after plant operator Tokyo Electric Power Co. began discharging filtered radioactive water that had been piling up at the plant since the triple meltdown triggered by the 2011 earthquake and tsunami disaster.

Special equipment is used beforehand to remove harmful substances from the tainted water. However, tritium, a radioactive isotope of hydrogen, cannot be removed under the Advanced Liquid Processing System process.

TEPCO began releasing water into the Pacific Ocean on the afternoon of Aug. 24.

The agency said one flatfish and one sea robin caught 4 to 5 kilometers early on Aug. 25 were analyzed.

Measurements will be taken daily for the next month or so, and the results will be posted on the agency’s website.