Whaling vessels left the ports of Shimonoseki, Yamaguchi Prefecture, and Habu in Onomichi, Hiroshima Prefecture at the weekend to conduct their "scientific research" in the northwest Pacific Ocean over the next three months through until late August.

Led by the Nisshin Maru the fleets plan to capture 260 minke and various other species of whales to study their stomach contents, DNA and other information. The fleet returned to Japan in February after halting its scientific mission in the Antarctic Ocean that commenced some months earlier, they killed 172 whales. It will be the 18th scientific expedition to take place in the northwestern Pacific. Japan has hunted whales since 1987 for what it says are scientific research purposes after officially halting commercial whaling in line with an international moratorium, however it's simply a cover for the continuation of commercial whaling.

The International Whaling Commission at its annual meeting last June discussed a proposal to allow Japan to hunt whales in Japanese coastal areas in exchange for a reduction of its annual catch limit for research whaling, but the proposal was deferred.