A months-long inspection of Marineland by Ontario's animal welfare watchdog has found that marine mammals at the tourist attraction were in distress due to poor water quality.

Ontario's top court has affirmed the policing powers of the province's animal welfare agency, striking down a lower court's ruling that called into question the constitutionality of private law enforcement.

The Ontario Society for the Prevention of Cruelty to Animals, whose officers have police powers and can lay both provincial offence and criminal animal cruelty charges, said lack of funding and years of financial losses had led to the decision.