Amid worldwide protests, Japanese fishing authorities this past December postponed plans to kill as many as 50 humpback whales for research. The controversy, including official U.S. criticism of the proposed hunt, underscores the privileged role humpback whales play in the public imagination as one of the most charismatic sea creatures.

The incident also cast a harsh light on a provision in the international whaling agreement that allows nations to permit killing whales for scientific purposes. Indeed, Japanese officials say they're going forward with plans to kill nearly 1,000 whales of other species this year under the research exemption. Iceland and Norway have invoked the exemption in the past, but Japan attracts the most criticism because of the scale of its hunts and its stated goal of easing whale-hunting restrictions. Some marine biologists criticize the Japanese work as little more than a cover for industrial-scale hunting of whales for food. Japanese authorities acknowledge that whales hunted for research are processed at sea and that the meat is sold in stores and served in restaurants in Japan.

Whale hunting is regulated by the International Whaling Commission (IWC), formed in 1946 with 15 member nations (including the United States) and now numbering 78. The humpback was one of the first whales to receive protection: in 1966, the IWC enacted a worldwide moratorium on hunting the species. The IWC extended the moratorium to all commercial whaling in 1986.

Citing the research exemption, Japanese whalers have killed more than 10,000 whales since the late 1980s, according to the IWC. Most were minke whales, which are relatively abundant, but others were less common Bryde's, sei, sperm and fin whales. One of Japan's representatives to the IWC, Joji Morishita, says whales are a "natural resource" and "should be managed in a sustainable manner" based "on science and not emotion."

Opposition to the research hunts is widespread. Even the IWC—essentially a diplomatic body with no enforcement power—has asked Japan to suspend its scientific whaling program. An IWC resolution notes that none of the Japanese research is necessary for managing whale populations. Nick Gales, a marine biologist with the Australian Antarctic Division in Kingston, Tasmania, says the scientific rationale for killing whales is "nonsense." The International Fund for Animal Welfare in Tokyo is one of many advocacy groups to oppose the lethal research.

The long-simmering controversy came to an angry boil this past November when Japanese whalers set out to hunt humpbacks in the Southern Ocean Sanctuary to study whether they are competing with minke whales for food. Australia led the opposition to the hunt; it announced that it would send planes and a ship to monitor Japanese whalers. Humpback researchers scoffed. "There's nothing that we need to know about humpback whales that requires using lethal techniques," says the Dolphin Institute's Lou Herman.

Japanese fishing authorities said they would hold off—for now—and not kill any humpbacks before the IWC meets in June. U.S. Commerce Secretary Carlos Gutierrez said, "we applaud Japan's decision as an act of goodwill toward the International Whaling Commission."