A flotilla of four whaling ships left Ayukawa Port in Ishinomaki, Miyagi Prefecture, on Thursday to kick off this season's research hunt for minke whales.
The plan is to catch up to 60 minke whales off the Sanriku region through early June and check them for radiation, industry officials said.
The captured whales will be dissected and their gastric samples analyzed to research the mammals' impact on the ecosystem.
If radiation levels in the meat are found to be under government-set standards, it will be put on the market, the officials said.
The Fukushima No. 1 power plant is still struggling to find safe ways to store the vast amounts of radioactive water it is generating to keep the wrecked reactors cool. Some experts believe significant amounts are finding their way to the sea.
The ships will stay overnight at Ishinomaki Port because work to rebuild the breakwater at Ayukawa Port is still under way.