The dolphin hunting season has officially started in the town of Taiji, north-west of Japan.

Officials made the announcement on Monday, adding that bad weather conditions will delay the beginning of the killings, which will end in February.

The whale hunting season, also started on Monday, will last until April.

The announcement came on the same day as animal rights advocates in Japan planned to mark Japan Dolphin Day and demonstrate against the hunting season which, according to the protesters, is not part of the tradition of Japanese people.

"[The hunts] exist only for making big profits for the fishermen and the companies that buy live dolphins for their facilities," the NGO Save Japan Dolphins said. "The hunts began in 1969, and several other Japanese towns (Iki Island and Futo) have given up their drive hunts. There is no excuse for Taiji to claim that opponents are against their 'food culture' or 'ancient traditions'."

Worldwide protests

According to the charity Whale and Dolphin Conservation (WDC), some 850 dolphins of mixed species were killed in the hunts in 2013, while more than 150 were taken alive for captivity. A similar number of dolphins is expected to be killed or captured this year.

The issue of dolphin hunting in Japan sparked international outrage after the release of the 2009 documentary The Cove, directed by former National Geographic photographer Louie Psihoyos, which shows the capture and slaughter of some dolphins during the hunting season.

The documentary claims that more than 20,000 dolphins and porpoises are killed every year in Japan.

The Cove prompted hundreds of activists worldwide to protest against the hunting, with some demanding Japan to be banned from hosting the 2020 Summer Olympics.