The Japanese town chronicled in the award-winning film The Cove for its annual dolphin hunt that turns coastal waters red with blood has suspended killing the animals - at least for this week's catch - following an international outcry.

The western Japanese town of Taiji will sell some of the animals to aquariums as it does every year, but the remainder of the 100 bottlenose dolphins that were caught early Wednesday in the first catch of the season are to be released.

In the past, they were killed and sold for meat.

An official at the Taiji fisheries association, who spoke on condition of anonymity because the town abhors the publicity its dolphin-killing has drawn, said on Thursday that the decision was made partly in response to the international outcry created by The Cove.

The West Australian highlighted the slaughter in an investigation in December last year.

The revelations increased pressure on Japan to end the slaughter and stretched sister city relations between Taiji and Broome.

Public meetings were held in Broome amid growing anger over the practice. Councillors had unanimously voted to "respectfully advise" Taiji that Broome would be unable to fulfil its obligation as a sister town while the dolphin killings continued.

The Taiji fisheries association spokesman today said about 50 of the dolphins will be hand-picked for aquariums and the rest will be set free, although a time for that has not been set.

In today's hunt, the fishermen also caught 50 pilot whales, which were slain and sold as meat, he said.

He said it was unclear whether the town would stop killing dolphins.

Residents wanted to avoid trouble, but did not want to cave in to activists and give up what they see as a tradition.

Ric O'Barry, 69, the star of The Cove and dolphin trainer for the 1960s Flipper TV series, welcomed the news, saying it was a sign that overseas pressure had worked and expressing hope that the town would now institute a "no-slaughter policy".

"I am elated," Mr O'Barry said from Tokyo.

"When I heard that, I did a backflip off the bed here."

Last week, Mr O'Barry visited Taiji, a village of 3,500 people in Wakayama Prefecture, with his camera crew to try to deliver the message the dolphins must be saved.

The Cove, which has collected about a dozen awards, including this year's audience award at the Sundance Film Festival, juxtaposes stunning underwater shots of gliding dolphins with horrifying scenes of the panic-stricken mammals getting speared in a cove as the water turns red with blood.

Mr O'Barry and his group not only oppose the slaying but also keeping them in aquariums.

Although Mr O'Barry was instrumental in making dolphins popular in marine shows, he regrets having trained them and now believes they should be left alone in the wild.

When he visited the Taiji aquarium, he was outraged that the dolphins were being kept in tiny tanks.

Dolphin meat is consumed as a delicacy in the region and some other areas but most Japanese have never eaten it.

Meat from one dolphin fetches about Y50,000 ($A628) but dolphins can be sold to aquariums for 10 to 20 times that price, with some kinds going for as much as $US150,000 ($A173,832).

The Japanese Government, which allows a hunt of about 20,000 dolphins a year, argues that killing them and whales is no different from raising cows or pigs for slaughter.

Taiji has killed about 2,000 dolphins a year during an annual season that starts in September and continues through about March, but their hunt depends on the weather and other factors.

Wednesday's dolphin catch was this season's first.

Taiji residents say they have killed whales and dolphins for hundreds of years as part of their fishing lifestyle because their region is not fit for rice farming.

They feel attacks from Western conservationists are unfair, noting that other animals such as cows and deer are slain for meat for food.