MARINE MAMMALS -- A U.S. appeals court has ordered American anti-whaling activists to keep 500 yards away from Japanese whaling ships off Antarctica, the Associated Press reports.

The 9th U.S. Circuit Court of Appeals issued an injunction Monday against the Sea Shepherd Conservation Society, which sends vessels every December to disrupt whale killings by Japan’s Institute of Cetacean Research.

The three-judge panel ordered Sea Shepherd not to attack or approach any of the Japanese vessels until it can rule on the merits of an appeal from whaling groups.

Japan’s whaling fleet kills up to 1,000 whales a year, as allowed by the International Whaling Commission. Japan is permitted to hunt the animals as long as they are killed for research and not commercial purposes.

But whale meat not used for study is sold as food in Japan, and critics say that’s the real reason for the hunts.

Sea Shepherd activists use stink bombs, lasers and other nonlethal means to interfere with the whalers. The group argues that its activities are supported by international law and that American courts don’t have jurisdiction in the Southern Ocean.

In a news release, the group’s president, Paul Watson, said it is evaluating the court’s order.

“I can tell you with complete certainty, however, that Sea Shepherd remains committed to upholding the integrity of the Southern Ocean Whale Sanctuary and ensuring the whalers go home with zero whales killed,” he said.

The organization’s vessels have not yet reached the Southern Ocean, the AP reported today.