by Frank Zeller

TOKYO (AFP) – Japan recalled its Antarctic whaling fleet a month early Friday, citing the threat posed by militant environmentalist group Sea Shepherd and demanding foreign countries crack down on the activists.

Tokyo told Australia, New Zealand and the Netherlands to take action against the US-based group, which has used their ports or flown their flags in its campaign to stop Japanese whalers from killing the sea mammals.

Sea Shepherd, which says its tactics are non-violent but aggressive, has hurled paint and stink bombs at whaling ships, snared their propellers with rope, and moved its own boats between the harpoon ships and their prey.

On Friday, Japan said it was bringing home its four whaling ships, weeks before the usual end of the annual cull in mid-March, citing the need to protect their crew from Sea Shepherd's sustained harassment.

Japan -- which hunts the ocean giants under a loophole to a global ban that permits lethal "scientific research" -- has killed 172 whales this season, only about a fifth of its target, the fisheries agency said.

Prime Minister Naoto Kan's top spokesman Yukio Edano called Sea Shepherd's actions "extremely deplorable" and said: "We can't help but feel outrage because the lives of the crew were endangered."

Edano also pledged that Japan would keep hunting whales, telling a news conference: "We will work out definite measures to ensure we can continue research whaling without giving in to sabotage."

Foreign Minister Seiji Maehara said Tokyo had summoned the Australian, New Zealand and Dutch ambassadors and made "a strong request to take effective measures to avoid the recurrence of Sea Shepherd's obstructionist activities".

Australia -- which last year launched legal action against Japan's whaling programme at the International Court of Justice -- and New Zealand earlier on Friday said they hoped Japan had given up whaling for good.

Sea Shepherd, which was still chasing the Japanese fleet in Antarctic waters, hailed the end of this year's cull, the first time their activism has cut short the annual hunt, but pledged to keep shadowing the vessels.

"It's great news," group founder Paul Watson told AFP by satellite phone.

"We will however stay with the Japanese ships until they return north and make sure that they're out of the Southern Ocean whale sanctuary."

Sea Shepherd, supported by Hollywood stars such as Sean Penn and Pierce Brosnan, this season operated three boats and a helicopter.

Last year, its futuristic speedboat the Ady Gil sank after a collision with a whaler. Its captain, New Zealander Peter Bethune, boarded the Japanese ship weeks afterwards, was detained and later handed a suspended jail term.

Japan has long defended whaling as part of the island nation's culture and makes no secret of the fact that the meat ends up in restaurants.

Tomoaki Nakao, the mayor of Shimonoseki, the port from where the whaling ships leave each year, said: "I want Japan to maintain a firm stand and continue appealing to the world about the legitimacy" of scientific whaling.

The US-based International Fund for Animal Welfare (IFAW) voiced cautious optimism that Japan would end the state-funded whaling programme, which it said had cost the country in both diplomatic and financial terms.

"It's not the end of Japanese whaling and it's not the beginning but it might be the beginning of the end of commercial whaling in an international sanctuary," said Patrick Ramage, director IFAW's Global Whale Programme.

Greenpeace has long argued that the state-financed whale hunts are a waste of taxpayer money and produce excess stockpiles of unwanted whale meat.

"We want people in Japan and abroad to understand that behind the decision this time is the fact that fewer and fewer Japanese people eat whale meat," said the group's campaigner Junichi Sato.