In mid-January, somewhere between 250 and 500 dolphins were driven into the cove near Taiji, a small town in western Japan made famous in the award-winning film, “The Cove.” There, at least 100 of the dolphins were slaughtered for their meat. Others were packed up and sold to aquariums.

The dolphins are herded, butchered and sold every year, but this year, the Sea Shepherd Conservation Society, together with CNN news uploaded videos of the dolphin hunt. The video, available online, is not for the faint of heart. Despite claims of humane killing methods, the video shows the fishermen hacking into the heads and backs of the panicked dolphins, then leaving them to bleed to death, turning the entire cove bright red.

Prime Minister Shinzo Abe defended the practice in an interview with CNN and Chief Cabinet Secretary Yoshihide Suga told reporters at a news conference that marine mammals including dolphins were “very important water resources.” Suga insisted “Dolphin fishing is one of the traditional fishing forms of our country and is carried out appropriately in accordance with the law.”

Their argument that the force of tradition justifies the herding, capturing and slaughtering of dolphins is a flimsy one. Many past cultural practices, such as slavery, bordellos and beheading were stopped for ethical reasons. Tradition and culture are forces that change in accordance with new scientific understanding and evolving ethical standards. In addition, the Taiji hunt didn’t even become institutionalized on a large scale until 1969, so its roots are quite shallow.

Their argument that the slaughter adheres to principles of the law is equally questionable. Veterinarians and behavioral scientists who viewed the covertly recorded video contend that the killing method used in this year’s Taiji dolphin hunt would not be permitted in any slaughterhouse in the developed world.

Indeed, it is open to question whether the method would be acceptable if used to slaughter cows or other livestock in Japan.

Japanese law states that all methods of killing livestock should reduce the animals’ suffering as much as possible. The method of sending “fishermen” into the water with knives to stab the dolphins, clearly evident in the video, does not begin to meet that guideline. The desperate flailing of the wounded animals and the long time it takes them to die go against the accepted animal welfare standards employed in advanced societies.

Japan has already stopped invasive research and other harmful practices on species such as chimpanzees. Intelligent animal species have always held a special closeness to humans because of their intelligence, capacity for suffering and complex social relations. Dolphins are even known to commit suicide when distressed or confused.

Japan has another tradition, one of deep respect for nature and the creatures in it. That tradition would be much easier to defend. The dolphin hunt is an inhumane practice that should be stopped.