Animal advocates gathered outside Marineland with placards on Saturday afternoon to protest the alleged mistreatment of animals at the Niagara Falls, Ont. attraction.

The demonstration was organized by Marineland Animal Defense (M.A.D.), a campaign dedicated to ending animal captivity and breeding programs at the amusement park.

Protesters began lining roadways outside of Marineland at about noon, some carrying cardboard signs denouncing the aquatic theme park.

Criticism of the park has been mounting following the publication of a Toronto Star report in which former trainers claimed animals were suffering from neglect and unhealthy conditions.

In an interview with CTV’s Canada AM, former trainer Phil Demers said he decided to leave his job of 12 years after witnessing ongoing animal suffering.

He alleged that ongoing problems with the park’s water were making sea lions lethargic and unresponsive, while causing the skin to flake off of dolphins.

Marineland defended the park’s upkeep in a statement emailed to CTV News earlier this week, saying animals enjoy well-maintained facilities, high-quality diets and exemplary veterinary care.

In a message posted to Facebook, protest organizers said Demers was expected to attend Saturday’s rally, though it’s currently unclear if he was present.

M.A.D. has encouraged those who are unable to attend the rally to write to NDP MP Libby Davies, urging her to re-introduce a Private Member’s Bill related to the import and export of wild captured animals.