Former workers at Marineland — one of Ontario's top tourist attractions — are accusing the facility of mistreating animals.

The charges were documented in the Toronto Star on Tuesday.

Phil Demers, a former trainer at the Niagara Falls aquarium, says some of the animals are not well cared for.

"Before I left, a lot of the animals eyes were ulcerated, we had to treat all the animals with antibiotics and valium and a number of different medications," he told CBC News.

Some of the animals have gone blind due to what Demers alleges are poor water conditions. Other animals, he says, are locked in waterless pens for days.

"I would assess the animals' health as very poor when I left," Demers said.

But John Holer, owner of Marineland, denied those allegations. He told the Star in an interview that “We take care of the animals — better than I would take care of myself.”

June Mergel, the director of veterinary services for Marineland, also denies any animals are being mistreated.

"It would break my heart to think we would ever mistreat [the animals]. We love them dearly," said Mergel.

"We've been here for 50 years, so we have a lot of ex-employees that cycle through the area, and I can find you as many employees — ex-employees — that will say good things about Marineland."

Bill Peters, the national director of the Canadian Associations of Zoos and Aquariums, says it is really a self-regulated industry. In large part there is no one responsible for monitoring.

Peters admits "it is a real concern."

He said that CAZA inspected Marineland last year and gave it a pass and that CAZA has not received any complaints about the facility since that time.

But Peters says the only province that has actual laws forcing zoos and aquariums to be accredited is British Columbia. Those laws require a facility to maintain a certain standard of care.

"There are a lot of substandard facilities, in Ontario, they are commonly called road side zoos, and they're just not accountable," Peters admits.