Japan's biggest whaling ship returned to Tokyo on Monday bringing home only half its catch target after its expedition to the Antarctic Ocean was disrupted by anti-whaling protesters.
The Nisshin Maru, the main harpoon ship of the five-vessel fleet, docked in the Tokyo harbor with harvests from the five-month season that began in November. The rest of the fleet returned over the past few weeks, including a ship that brought back an environmental activist who brazenly boarded it to protest the hunt.
The fleet killed 506 minke whales and one fin whale during its expedition, fulfilling more than half its target of up to 935 mostly minke and some fin whales, Fisheries Agency official Takashi Mori said.
Japan's annual whale hunt is allowed by the International Whaling Commission as a scientific program, but opponents call it a cover for commercial whaling, which has been banned since 1986.
"The lack of samples could affect the accuracy of our research," Mori said of the low catch.
Japan has blamed U.S.-based conservationist group Sea Shepherd for repeated skirmishes at sea and escalating tensions every year by allegedly ramming into vessels and pelting whalers with bottles filled with rancid butter. Whalers have responded by firing water cannons and sonar devices to disorient the activists.
The 2009-10 expedition's catch was the lowest in recent years -- even below the 508 whales taken in the 2007 season, when the hunt was cut short after fire broke out on the mother ship.
Mori blamed "violent interference" by activists who paralyzed whaling for 31 days.
Japan hunts hundreds of mostly minke whales, which are not an endangered species. Whale meat not used for study is sold for consumption in Japan.
Sea Shepherd activist Peter Bethune was arrested for illegally boarding a whaling vessel in Antarctic seas after he jumped aboard the Shonan Maru 2 in February. Bethune said he wanted to make a citizen's arrest of the captain and handed over a $3 million bill for the destruction of a Sea Shepherd ship that sank after a confrontation a month earlier.
Bethune, 45, has since been in custody in Tokyo. Prosecutors earlier this month charged him with five criminal counts that could lead to a years-long prison term.
Sea Shepherd has described its efforts this year as its "most successful" Antarctic campaign against Japanese whalers.