The launch of five boats comes after Tokyo’s controversial decision to withdraw from the International Whaling Commission (IWC) on June 30 last year.
The French newsagency AFP reports the hunts are certain to spark criticism from environmentalists and anti-whaling countries but are cause for celebration among whaling communities in Japan who say the globally banned practice is a longstanding tradition.
The issue has been a diplomatic headache for Japan for years, with Tokyo using a loophole in the IWC rules to carry out hunts in protected Antarctic waters for “scientific” research purposes.
Those hunts were fiercely criticised, and Japan decided last year to withdraw from the IWC after repeatedly failing to convince the body to allow it to resume full-scale commercial whaling.
AFP reports whaling ships set sail on commercial hunts from several parts of Japan, including the town of Kushiro in northern Hokkaido.
A Japanese website has revealed a kill quota of 220 whales, in a catchment period from now until December.
This will include “50 Bryde’s whales, 50 minke whales, and 25 sei whales”.
The boats have come from different parts of the country, including Taiji, an area known for dolphin hunts.
Another flotilla of ships that once carried out whaling under the “scientific research” loophole will set out from Shimonoseki port in western Japan.
“We are very excited at the resumption of commercial whaling,” Yoshifumi Kai, head of the Japan Small-Type Whaling Association, told AFP ahead of the departure.
An open letter, sent by conservation groups and celebrities including Dr Jane Goodall, Stephen Fry and Ricky Gervais, pleaded with the Group of 20 (G20) global leaders meeting in Osaka to appeal to Japan to reconsider its stance on commercial whaling.
“Whales are iconic, long-lived and socially complex,” the letter read.
“They are important sentinels of the health of our oceans and contribute important ecosystem services to the marine environment.”
The Australian Marine Conservation Society (AMCS) has lashed Japan’s return to commercial whaling, calling it an “outdated and cruel industry selling a product to a market that has all but disappeared”.
“Japan has so far failed to even say how many whales they are going to kill,” said Darren Kindleysides, AMCS chief executive officer.
Mr Kindleysides said Japan is not able to simply “wash its hands” of international legal duties.
“Our legal opinion shows that established international laws and conventions, including the United Nations Convention on the Law of the Sea, mean Japan has a duty to co-operate with other countries. Japan is acting with impunity.”
“Today is a historic moment for all the wrong reasons, and the world is looking to Australia again,” he said.
Japan has hunted whales for centuries, and the meat was a key source of protein in the immediate post-World War II years when the country was desperately poor.
However, consumption has declined significantly in recent decades, with much of the population saying they rarely or never eat whale meat, and activists have put pressure on Japan to ditch the historic practice.
Tokyo’s withdrawal from the IWC ended its most provocative expeditions in protected Antarctic waters, and while it sparked a firestorm of criticism, some campaigners say it is the first step towards the end of Japanese whaling.
“Japan is quitting high-seas whaling that is a huge step towards the end of killing whales for their meat and other products,” said Patrick Ramage, director of marine conservation at the International Fund for Animal Welfare.
He said commercial whaling, in Japanese waters, was unlikely to have much of a future given dwindling subsidies and the shrinking market for whale meat.
“What we are seeing is the beginning of the end of Japanese whaling,” he said.