Sorrento, Italy ? Opponents of whaling won a victory Wednesday in their battle against the use of grenade-tipped harpoons when the International Whaling Commission approved measures aimed at saving the giant mammals from what animal-rights activists say are slow, painful deaths.

Pro-whaling nations at this year’s commission meeting insisted that this method of slaughter is quick and usually painless. But the animal-rights view won out, with the 29-22 approval of a resolution proposed by anti-whaling nation New Zealand.

The decision highlighted the power struggle within the IWC.

“Frankly, I was amazed that any country would vote against it,” New Zealand Conservation Minister Chris Carter, who presented the proposal, said.

“I think this became a political statement between pro-conservation countries and pro-whaling countries,” he said. “It shows how polarized the IWC has become.”

The resolution does not ban grenade-tipped harpoons or impose another slaughter method. Rather, it endorses the view that the technique can cause whales to suffer, and it orders the commission to research different methods.

“The reality is that whaling does occur. And if whaling is going to occur, at least it should be as humane as possible,” Carter said.

A ban on commercial whaling has been in place since 1986, but some hunting takes place under a scientific program. Environmentalists say this is just commercial whaling in disguise.

“Current whaling methods do not guarantee death without pain, stress or distress,” the resolution said. It criticized the methods used to determine when a whale dies or is no longer able to feel pain, and called for updated data on just how long the animals suffer.

“This is a real victory for whale welfare,” says Peter Davies, coordinator of Whalewatch, an anti-whaling umbrella organization. “Far too many whales have suffered and continue to suffer agonizing deaths from the whalers’ harpoon.”

Pro-whaling advocates expressed frustration.

“Japan has been working very hard to improve our killing methods, with positive results, and these have been reported to the IWC,” said a spokesman for the Tokyo delegation.

“Whale hunting is very humane and the killing techniques are extremely efficient,” said Rune Frovik, director of the High North Alliance of whale hunters from Canada, Iceland, Norway and other countries. “Those that are not killed instantaneously lose consciousness and don’t suffer any pain.”