A Toronto Star exposé this week reveals that Marineland is a house of horrors for the whales, dolphins, sea lions, and walruses trapped inside. The controversial marine-themed amusement park in Niagara Falls has long been the target of weekly protests and publicity campaigns and members of the surrounding community. Animal advocates believe animals at Marineland are mistreated, and that it is inherently cruel and immoral to confine marine mammals in tiny tanks while forcing them to perform stunts for our amusement.

Animal advocates have suspected for years that Marineland isn't a nice place for animals, but what goes on behind closed doors was largely a mystery -- until now.

The allegations are shocking. Eight former Marineland employees tell tales of sea mammals languishing in pain and distress due to abysmal water quality, improper facilities, and too few trainers.

Skoot, a baby beluga, died in May after being thrashed during a two-hour assault by adult belugas. Meanwhile, understaffing meant that no trainer was nearby to intervene.

The investigation details poor water quality and recurring water problems that cause serious suffering and distress to the animals. In the words of one former supervisor, "It got so that I didn't even have to test the water when I arrived in the morning. I could tell just by looking at how sick the animals were. If you don't look at them, there's no problem. What hurt me most is those animals in those pools. They can't go anywhere. They can't get out. They're stuck."

Walruses experienced chemical burns and ulcerated eyes. Sea lions suffered red, swollen, bulbous eyes (nearly all of Marineland's sea lions are blind or have vision problems). Dolphins were forced to live in concrete tanks in the murky green water, their skin falling off in chunks, thrashing about in response to new chemicals added to the water. Some animals would scrunch their eyes shut to protect against the water.

"The animals were in hell," said Phil Demers, a former senior trainer at Marineland. Demers reached a breaking point in the spring and quit his job because he felt worn down and frustrated that he was unable to help the animals in his care.

Physical suffering is an obvious concern, but psychological anguish is another. Four of Marineland's five orca whales have died since 2004, leaving Kiska, the sole surviving orca, all alone. Orcas live in pods, which is why the Canadian Association of Zoos and Aquariums disapproves of keeping orcas alone. The practice is banned in the U.S.

Former employees said that walruses, who are extremely social creatures, were confined in solitary, waterless cages. One walrus, Zeus, became a shell of his former vibrant former self, and was often left in his own excrement due to understaffing.

This rare glimpse into the misery at Marineland has outraged the public, with Marineland trending on Twitter, and many calling for the park to be shut down. But the other question on the public's mind is why Marineland has not been charged criminally and under provincial animal protection law. How could it be that whales, dolphins, walruses and sea lions have been suffering for so long, right under the nose of the local authorities? So far, the authorities have been silent on the Marineland investigation.

Niagara Falls mayor Jim Diodati defended Marineland because he has never personally seen evidence of neglect. This is precisely the terror of the animal entertainment industry. The animals perform for the public, and while visitors simply go home, the animals go in back to sleep in their own filth. Without proper regulation and oversight we depend on brave whistleblowers to uncover abuse.

Society is becoming increasingly uncomfortable with confining majestic sea animals for the cheap thrill of watching them perform. The truth about what goes on behind closed doors at Marineland will undoubtedly lead many more to question keeping wild animals in captivity.

You can encourage the authorities to charge Marineland by emailing the Niagara Humane Society, the OSPCA and the Niagara Region Police. Animals in captivity are among the most vulnerable in society, and it is our responsibility to protect them from the abuse and suffering described in the Toronto Star investigation.

Follow Camille Labchuk on Twitter: www.twitter.com/CamilleLabchuk