Of the more than 250 dolphins captured in a cove in Taiji, Japan across the last four days, 41 were killed and 52 were taken captive, according to a report by the Cove Guardians, an activist group affiliated with the Sea Shepherd Conservation Society.

Tuesday ended the annual dolphin cull in Taiji, which was made infamous by the 2009 Academy Award-winning documentary "The Cove."

The Cove Guardians said approximately 135 dolphins were driven back out to sea, but many of them may die there as a result of the lack of food, immobility and trauma they've faced by being corralled in the Taiji cove for four days.

"Many of these dolphins who were driven out will not survive and will soon be found washed ashore in the coming days," the group said in its account of the final day of the cull.

A number of high-profile people have spoken out against the dolphin-hunt, calling it inhumane and harmful to Japan's image.

Artist and peace advocate Yoko Ono, who was born in Tokyo, said the hunt tarnishes Japan's image as a peaceful country and provides an open invitation to criticism.

"At this very politically sensitive time, [the hunt] will make the children of the world hate the Japanese," she said in an open letter to the fishermen of Taiji, which was posted on her Imagine Peace website.

Caroline Kennedy, the US Ambassador to Japan, decried the practice in a Twitter message late last week.

"Deeply concerned by inhumaneness of drive hunt dolphin killing," Kennedy wrote. "USG opposes drive hunt fisheries."

A drive hunt refers to the practice of corralling dolphins into a cove or otherwise inescapable area, where they can be trapped or killed, and "USG" is a reference to the United States government.

Japan's whaling and dolphin-hunting programs have long been a controversial subject, and the nation frequently faces criticism for the practice. Japan, however, claims that hunting marine mammals is part of its cultural heritage.

Japan's Chief Cabinet Secretary Yoshihide Suga told reporters Monday that the Taiji dolphin cull was done in accordance with Japanese laws.

"Dolphin fishing is a form of traditional fishing in our country," he said, according to The Associate Press, which reported he was responding to a question about Kennedy's criticism. "We will explain Japan's position to the American side."

Taiji mayor Kazutaka Sangen said the criticism against the fishermen is unwarranted.

"We have fishermen in our community and they are exercising their fishing rights," he said, according to a USA Today report. "We feel that we need to protect our residents against the criticisms.

Eco-activist Paul Watson, who is founder of the Sea Shepherd Conservation Society, said in a blog post Sunday that "Capturing dolphins for display in aquariums is not part of Japanese culture and the brutality of this slaughter would never be legally accepted in any abattoir in the world including Japan."