In Japanese villages each year, local fishermen hunt for large numbers of dolphins by herding them into shallow coves and then, scientists say, attacking them with knives and even eviscerating them alive.
Now, a broad-based coalition including marine scientists and aquarium workers is demanding that the Japanese end these government-sanctioned dolphin drives, which opponents criticize as an inhumane annual practice that targets an intelligent and self-aware species.
"They're dying this sort of long, slow, painful, excruciating death," said Dr. Paul Boyle, the former director of the New York Aquarium and current chairman and chief executive of The Ocean Project, a Providence-based coalition that is helping coordinate the effort.
The group is sponsoring an online petition that asks the government to halt the huntings.
The Japanese say the practice is a long-standing cultural and commercial tradition.
Takumi Fukuda, fisheries attache for the Japanese embassy in Washington, said fishermen have tried to quicken the dolphins' deaths to lessen their suffering and to maintain the quality of meat.
But it was impossible, he said, to "avoid the cruelty completely."
"We should understand that all killing scenes of animals contain certain cruelty," Fukuda said in an e-mail interview.
In promoting their "Act for Dolphins" campaign, the scientists highlight dolphins' intelligence, keen sense of self-awareness and a cognitive functioning that they say is similar to that of apes.
"They have the intellect to understand what is going on," said Lori Marino, senior lecturer in neuroscience and behavioral biology at Emory University in Atlanta and one of the organizers. "We believe that that means that they undergo a great deal of suffering during this process."
The practice survives in just a few outposts in Japan, primarily in the coastal villages of Taiji, in western Japan, and Futo, 62 miles southwest of Tokyo. It runs through the fall into the spring.
Boyle said that while the Japanese contend dolphins compete with fishermen for fish, there is no scientific support for that claim.
The scientists said fishermen are able to corral large numbers of dolphins into nets by banging metal rods into the water, creating a sort of acoustic barrier.
From there, the scientists said, the dolphins are "dispatched in a brutal manner: speared, hooked, hoisted into the air by their tails, and finally eviscerated alive."
Marino and other scientists said the dolphins have been used as pet food and fertilizer, with their meat distributed across Asia.
Animal welfare groups already condemn the practice. The World Association of Zoos and Aquariums, for instance, has a code of ethics that prohibits its members from displaying animals acquired through these hunts.
But Marino said this campaign was significant because of its active involvement of marine scientists.
Diana Reiss, director of marine mammal research at the New York Aquarium and one of the coalition leaders, said she met with representatives of Japan's government at the Japanese Embassy in Washington, but that her concerns went unheeded.
"I don't think it's very well-known in Japan by the people themselves," Reiss said.
The coalition is trying to collect one million signatures for a petition it plans to present to the Japanese government.
But Fukuda said countries have varied attitudes about how to handle animals, and that one nation should not force its ideals on another.
"The Japanese dolphin fisheries are conducted not in the U.S. waters but in the Japanese waters," Fukuda said. "There is no international treaty in which Japan is a member and has officially authorized global standards for humanitarian handling of animals."