SeaWorld on the Gold Coast could be next on animal activists' hit-list if a US court battle to have whales protected under human anti-slavery laws succeeds.
People for the Ethical Treatment of Animals (PETA) is trying have the Thirteenth Amendment of the US Constitution, which prohibits human slavery, applied to whales at two theme parks.
A San Diego court will rule on whether five orcas are held in slavery or involuntary servitude at two SeaWorld parks in Florida and California.
The whales, named Tilikum, Katina, Corky, Kasatka and Ulises, perform water acrobatics at SeaWorld's San Diego and Orlando parks.
PETA Australia campaign manager Ashley Fruno says the Gold Coast's SeaWorld does not have whales in captivity, but does have dolphins and other animals "imprisoned" and suffering "the same deprivation as San Diego's orcas".
Ms Fruno says animals in aquariums are denied a natural existence.
"Every aspect of their lives is controlled and managed for the entertainment of humans," she said.
"So yes, we think that is akin to slavery."
PETA Australia's director of campaigns Jason Baker says it's possible the Gold Coast SeaWorld and any other amusement parks could be next on their hit list.
"We're always looking at the best avenues to help animals and if that involves filing a case on their behalf, then it's something we'd look at," Mr Baker said.
"But for now it's one case at a time."
The Gold Coast's SeaWorld declined to comment.
The case follows PETA's calls for SeaWorld to stop serving seafood at their aquarium, claiming it's like "serving poodle burgers at a dog show".
RSPCA spokesman Michael Beattie defended SeaWorld on the Gold Coast as playing a significant role in rescuing and rehabilitating wild animals.
He believes it's a very different park to those in the US.
"The animals, from what I can see, are not forced to exhibit unnatural behaviours that they would not do in the wild," Mr Beattie said.
"For example, having an elephant stand on its head compared to having a whale jump in the air and splash the water are totally different.
"It's unnatural for an elephant to stand on its head while it is natural for a whale to jump and splash."