Anti-whaling activists in Australia say their recent campaign in the Southern Ocean against Japanese whaling ships was the most successful ever. The Sea Shepherd Conservation Society says it stopped the Japanese fleet from hunting for about a third of the season.
The Sea Shepherd Conservation Society's boats have tailed Japanese whalers in the Southern Ocean for the past six annual hunts.
They aim to stop what they consider the illegal slaughter of humpback and minke whales in the icy waters of Antarctica.
This whaling season three Sea Shepherd vessels harassed the fleet, including a super-fast speed boat, the Ady Gil, which sank after a collision with a Japanese ship.
Despite the loss, conservationists say they had their most successful campaign ever, and claim to have cut the whalers' activities by a third, costing them an estimated $70 million in lost revenue.
Paul Wilson captain of one of the Sea Shepherd boats. He says his organization's tactics are increasingly troubling to the whalers.
"The Japanese are becoming clearly more frustrated and aggressive because they are losing a lot of money and this year they took that frustration out by deliberately turning in and ramming the Ady Gil and taking out a $2 million dollar ship," he said.
It is not known how many whales the Japanese caught during the southern hemisphere summer, although in the past Tokyo has set a quota of around 1,000 animals.
Two Sea Shepherd boats are docked in Tasmania after several weeks tracking the whalers. The Australian Federal Police searched both vessels at the request of Japanese authorities, who accuse the group of piracy and violence. So far, the group's members have not been charged with any offense.
Japan says the fleet takes whales for scientific research, although the meat is later sold. Critics, including the Australian and New Zealand governments, think the annual hunt is an attempt to circumvent international laws that bar commercial whaling.