Tokyo, Sep 2 (IANS): Japan has started its controversial annual dolphin hunt in the coastal town of Taiji, a media report said on Monday.

The hunt sees the animals driven into a cove where some are slaughtered for their meat with knives in shallow waters, the BBC report said.

Other dolphins are sold to aquariums and marine parks.

This year's Taiji hunt kicked off on Sunday, but according to Japanese media the boats returned without any dolphins.

On Monday, the fishing fleet went out again to drive a dolphin pod towards the shore.

Environmentalists have said that the practice is cruel because the dolphins can take up to 30 minutes to die by suffocation or drowning.

But the fisherman from Taiji say the community's livelihood is dependent on the trade.

The dolphin hunting season is expected to last for about six month.

The Taiji hunt has been carried out for decades and gained global attention when it was the subject of the Oscar-winning documentary "The Cove" in 2009.

Japan has already come under criticism this year for resuming commercial whaling after it left the International Whaling Commission (IWC).

Commercial whaling ships left port on July 1 this year and the first whales have already been killed and sold.