CANBERRA (Reuters) - Australia joined New Zealand on Thursday in investigating a clash between an anti-whaling protesters and Japanese whalers, but refused to send a patrol ship to Antarctic waters as activists promised a "whale war".
Canberra called for calm on all sides after the hardline Sea Shepherd Conservation Society's futuristic powerboat Ady Gil had its bow sliced off in a collision with the Japanese ship Shonan Maru No. 2 on Wednesday and was left foundering in frigid seas.
"It concerns me deeply. It's clear that emotions are running high and that lives are at risk," Australia's Acting Prime Minister Julia Gillard told reporters. "It seems miraculous to me, having seen the video, that lives were not lost."
New Zealand, where the Agy Gil was registered, has already launched an investigation into the clash and Gillard said Australia's maritime safety body would undertake a second probe that could lead to court if either side were found at fault.
In Tokyo, a Japanese government spokesman said an official protest had been lodged with New Zealand's government.
"The Japanese government sees this as extremely regrettable," said Chief Cabinet Secretary Hirofumi Hirano.
Confrontations between whalers and opponents have become an annual feature of the hunt in Antarctic waters claimed by Australia but not recognized as Australian by Japan. Gillard said the incident occurred just outside Australia's economic zone.
Sea Shepherd founder Paul Watson, who Japan has previously called an "eco-terrorist", said he wanted protection from Australia's navy for his protest fleet, now reduced to two ships.
"We now have a real whale war on our hands and we have no intention of retreating," Watson said.
Environmentalists accuse Australia of going soft on threats of an International Court of Justice whaling challenge to avoid damaging Canberra's $58 billion trade relationship with Japan.
Australian opposition and green lawmakers demanded the government send a customs ship to the area to ease tensions.
"These are Australian waters. Australia has not only a right but an obligation to be policing them," said Australian Greens Leader Bob Brown.
Canberra sent a customs icebreaker to Antarctic waters in early 2008 to monitor the Japanese whaling fleet and gather photographic and video evidence for a legal case.
But Gillard said Australia would not be sending a patrol ship again, saying the 2008 moved had failed to "influence behavior".
Both countries have in the past agreed to quarantine their differences over whaling from wider diplomatic relations to avoid damaging close security ties and long-running free trade talks.
Australia has managed to protect its major trade ties in Asia from periodic bilateral tensions, most notably the detention of an Australian mining executive in China in 2009.
JAPAN SAYS COLLISION UNAVOIDABLE
Japan's Fisheries Agency said the collision took place when Ady Gil suddenly slowed down as it crossed in front of Shonan Maru, which had warned the boat of impending danger.
All six crew were rescued from the Ady Gil, but the clash left one activist with two broken ribs and the A$1.5 million ($1.37 million) carbon-fiber trimaran foundered. Sea Shepherd expected the powerboat to be unsalvageable.
New Zealand Foreign Minister Murray McCully said sending an Australian patrol ship would not lead to automatic restraint.
"People are going to behave badly down there. There's not much we can do about it," McCully told Australian radio.
Law expert Don Rothwell said if the Japanese captain was found at fault, legal proceedings would likely occur in New Zealand.
Concerns could also be raised by the London-based International Maritime Organization following reports the Japanese vessel fled after the collision, said Rothwell, from the Australian National University.
Commercial whaling was banned under a 1986 moratorium, but Japan continues to cull whales, saying it is for research purposes, deflecting criticism from anti-whaling nations.
Japan says whaling is a cultural tradition and while most Japanese do not eat whale meat regularly, many are indifferent to accusations that the hunting is cruel.