Local fishermen in Fukushima Prefecture on Wednesday restarted operations suspended late last month after heavy amounts of contaminated water from the Fukushima No. 1 nuclear plant was found leaking into the ocean.

A fleet of 20 fishing boats set off at around 2 a.m. from the port of Matsukawaura in the city of Soma, 45 km north of the nuclear complex that was severely damaged in March 2011 earthquake and tsunami.

The boats returned shortly after 2 p.m. and began unloading their catches, according to the Soma Futaba fisheries cooperative, an arm of the Fukushima Prefectural Federation of Fisheries Cooperative Associations.

Trial operations. suspended for 15 months amid the nuclear crisis, restarted in June 2012 only to be halted Aug. 28 after Tokyo Electric Power Co. disclosed the water leaks the day after the Upper House election.

On Tuesday, the federation decided to resume trial fishing after a string of radiation tests by member co-ops did not find any readings above the government's 100 becquerels per kilogram safety limit for food products.

Of the 100 fish and seafood products tested, 95 were clear of radioactive material, with the other five containing less than 1/10 of the limit, the federation said.

"We must carry out this trial operation to demonstrate to Tepco, the government and society that we are determined to act with an eye to starting full-fledged operations," Hiroyuki Sato, chief of the fisheries co-op, told a group of fishermen prior to the fleet's departure.

The 20 fishing boats that took part in Wednesday trial operations are seeking to catch 18 species of fish and other seafood, including octopus and squid.

The federation said Tuesday that it would put the catches on sale after confirming that radiation readings for the catch is below 50 becquerels per kilogram — less than half the mandatory limit.