Japanese fishermen will set sail on Monday to hunt whales commercially for the first time in more than three decades, after Tokyo's controversial decision to withdraw from the International Whaling Commission.The hunts are likely to spark criticism from environmentalists and anti-whaling countries, but are cause for celebration among whaling communities in Japan, which says the practice is a long-standing 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.Whaling ships will set sail on commercial hunts from several parts of Japan on Monday, including the town of Kushiro in northern Japan's Hokkaido.The group of five small vessels could already be seen at the port there on Sunday. 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. "My heart is full of hope," he added.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.But consumption has declined significantly in recent decades -- with much of the population saying they rarely or never eat whale meat -- and activists have pressed Japan to ditch the practice.Tokyo's withdrawal from 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."