The Coffs Harbour Chamber of Commerce says an animal rights campaign encouraging people not to visit dolphins in captivity could be damaging for Coffs Harbour tourist attraction Dolphin Marine Magic.

The advertisement, which will be displayed on Busway buses throughout the city, shows a dolphin trapped inside a fishbowl alongside the words "Please think twice before visiting captive dolphins".

The advertisement is the initiative of the animal rights group Australia for Dolphins and was funded by Voiceless, the national animal protection institute.

Chamber of Commerce president George Cercato described the advertisement as "crude", and said businesses were "up in arms".

"It is a blatant attack on our most iconic attraction in Coffs Harbour," he said.

"It's not just going to stop the tourism; what about the good work done at this place?"

Mr Cercato said the group was failing to see the whole picture.

"Dolphin Marine Magic has got the theatre card which is their income stream, but they do good things for marine rescue," he said.

"They save and return so many animals, they have an education institution, and they help a fair few marine research places and universities.

"We've sent the CEO [of Australia for Dolphins] and directors emails; we've tried to make contact and get them to understand."

Australia for Dolphins defends campaign

CEO of Australia for Dolphins, Sarah Lucas, stood by the organisation's decision to run the campaign.

An example of the ads appearing on the side of some Coffs Harbour buses ( Supplied: Australia for Dolphins )

"Coffs Harbour is one of two places in Australia which still has a dolphinarium (sic)," she said.

"There's a vast amount of science which shows that dolphins suffer high levels of disease and stress and death when they're kept in swimming pools.

"We want people to think about it before they go and support that kind of cruelty to dolphins."

She said the "dolphinarium" did not do conservation work with dolphins and rejected the notion it provided a useful learning space.

"It isn't genuine education to have people come and see dolphins painting on canvasses or seeing dolphins play football," she said.

"That doesn't give people a sense of what wild dolphins do, or what the threats to them are, or why we should conserve them."