Dolphins swim at an aquarium of Yokohama Hakkeijima Sea Paradise, south of Tokyo, March 20, 2007. REUTERS/Kim Kyung-Hoon

Residents of Japanese town defended their annual dolphin hunt on Wednesday as a U.S. documentary showing the event premiered at a Tokyo film festival to a sell-out audience.

The Cove, which opened in the United States in July, follows a team of activists, including former dolphin trainer from the Flipper television series Ric O'Barry.

They battle Japanese police and fisherman to gain access to a hidden cove in Taiji, southern Japan, where barbed wire blocks people from filming dolphin killings that begin in September each year.

Taiji mayor Kazuzaka Sangen, who was among more than 150 people who saw the film at the Tokyo International Film Festival, was skeptical about whether it would change the long tradition of dolphin hunts in his town.

We have been like this for long time and though I don't know why the film people came to our town, no one will be scared because of this, he told Reuters.

The documentary shows fishermen luring thousands of wild dolphins into the cove, where activists say they are captured for marine amusement parks or slaughtered for food.

Fishermen in Taiji say dolphins need to be culled regularly to protect their fishing grounds.

Taiji residents who saw the film said it misrepresented them.

It's true that dolphins are being killed in the Japanese sea, but I hope people around the world also know that there are as many people that take care of dolphins every day, said Gou Mihashi, a 37-year-old dolphin trainer from Taiji.

The hunting of dolphins and whales in Japan has long been the subject of criticism from anti-whaling countries and environmental groups.

But the Japanese government defends the hunts, saying they are a cherished cultural tradition and no different from killing other animals.

The film's director, Louie Psihoyos, said he had wanted to show the documentary to a Japanese audience.

I felt that it was really important to get the film out here to make a stand, not to be safe in America but to risk everything to come here to show the film to the Japanese people, he told a news conference.

I really feel like... if this movie gets seen in Japan, it will be a huge win for the Japanese people and it will be a huge win for dolphins and the environmental movements.

Mari Shigehisa, a Japanese college student, was taken aback by the film.

I was shocked by the last scene of the film where dolphins were slashed and killed in a sea of blood, said Shigehisa, 21, after seeing the film. I think most Japanese people would not know about this.