20/01/2017 11:35 AM AEDT | Updated 20/01/2017 12:34 PM AEDT

Why Does Australia Still Keep Dolphins In Captivity?

There are two dolphin shows left in Australia.

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Home and Away actress Isabel Lucas wants dolphins in captivity to end.

Actress Isabel Lucas is calling for an end to the controversial practice of captive dolphin shows in Australia.

"It's heartbreaking to know dolphins are confined in chlorinated pools in Australia," Lucas said in a statement for Australia for Dolphins.

"Studies show captive dolphins suffer stress, anxiety and die young. Just last year a baby dolphin died in NSW after swallowing metal and litter. I urge all Australians to take a stand against this cruel practice, and choose to see dolphins in the wild rather than marine parks."

There are two remaining dolphin parks in Australia -- Dolphin Marine Magic in Coffs Harbour and Sea World on the Gold Coast in Queensland.

While the practice is legal, the RSPCA publicly states dolphins should not be kept in captivity because "their needs cannot be adequately met in a captive environment".

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Dolphins, like these ones in Indonesia, can be trained, but it's not enough stimulation for these intelligent, socially complex animals.

In May, the Labor party, Greens and the Animal Justice Party pledged their support of a bill to end dolphin captivity in NSW, which did not succeed.

Why doesn't the RSPCA support dolphins in captivity?

In the wild, dolphins may travel over 100 kilometres in a day, deep dive several hundred metres and travel more than 40 kilometres per hour, all of which are impossible in captivity. In addition, they rely heavily on echolocation to 'see' their natural, complex home.

Being confined in pools without complex seascapes to explore severely restricts their normal behaviour as well as their ability to swim naturally and encounter novel environments.

Studies have shown that dolphins in captivity can suffer stress resulting in appetite loss, ulcers, and increased susceptibility to disease due to changes in their social grouping, competition over resources and unstable social structures.

Social grouping has been recognised as one of the most important issues affecting health and welfare of captive cetaceans.

Source: RSPCA

Former NSW Premier Bob Carr last year told The Huffington Post Australia he tried to close dolphariums when he was in power.

"It was a pretty lonely decision back in the 1980s," Carr said.

"Public consciousness on animal cruelty wasn't as strongly developed as today and people were nervous about closing dolphinariums but I was persuaded by the arguments and I put those arguments to political colleagues."

Celebrities calling for an end to captive dolphin parks

Ricky Gervais

"Dolphins are amazing animals deserving of our respect. The UK has phased out dolphin captivity -- Australia, please do the same."

Dame Jane Goodall

"Cetaceans are highly intelligent and very social animals with complex communication patterns who often travel in large pods over long distances.

"In captivity they are forced to live in a low-sensory environment, which is clearly unable to fully meet their physical and emotional needs.

"Scientific research makes it clear that dolphins suffer greatly in captivity and I urge Australia to abolish its two remaining dolphinaria."

Tim Winton

"It turns my stomach to see cetaceans of any kind confined for commercial entertainment. Such a practice has no place in a civilised society.

"There's no excuse for it to continue, no ethical defence, no scientific or education purpose to justify it. So let's put an end to dolphin captivity in this country forever."

Xavier Rudd

"A lot of kids these days are pretty well informed and keen to learn where we went wrong. It's often kids educating their parents on things like the ludicrous idea of keeping cetaceans in confinement.

"Unfortunately we seem to procrastinate far too long on shifting mistakes of the past. This is a blatantly obvious one, let's show the young hearts some effort and get it done straight away!"