More than 20 demonstrators sabotaged the presentation shortly after 11.15am (Queensland time) to protest against the Gold Coast theme park's ongoing "exploitation" of dolphins and other marine mammals for "human entertainment".

Armed with placards and a loud hailer, the group jostled with security while shouting "there's no excuse for animal abuse" and encouraging hundreds of paying customers to demand refunds.

But after more than four minutes of chaos, it became clear the stunt had backfired.  As a chorus of boos gathered volume inside the packed arena, angry onlookers began exiting their seats to personally confront the protesters.

"We were there for a passive action," said one protester, Daniel Wolf, who added: "We expected some hostility ... but never that much."

Sea World is home to about 30 dolphins, all housed in a series of pools and man-made lagoons.

According to its website, the park's feature dolphin presentation "Affinity", which runs twice daily, offers an "unforgettable experience".

It adds: "Discover the powerful affinity shared between these magical mammals and their human friends, and learn about how we can make a difference together to actively care for the precious life of the oceans."

But according to the Justice for Captives activist group who ambushed this morning's event in front of a sell-out audience of about 1000, the park is a "cruel aqua prison" promoting "cruel shows for commercial profit".

"Seaworld lie," claimed group spokeswoman Angela Banovic.

"They tell people they can't release the dolphins because they are rescued and injured.

"But if these dolphins are well enough to perform demeaning tricks for human entertainment and corporate greed, then they are well enough to be released into the wild."

Numerous countries have banned dolphins being confined in captivity including the UK, Switzerland, Hungary, Chile and India.

A Sea World spokesman described the incident as a "slight disruption" and the theme park was "very proud" of its world class exhibits including some of the "largest filtered natural sand bottom lagoon systems in the world for dolphins".

He added Sea World's marine animal health and welfare program was "designed to promote a long, enriched life."