His lawyer Andrew Burns says Holer died in his home Saturday morning surrounded by family.
The tourist attraction Holer founded 1963 has grown into a large amusement park with whales, dolphins, walruses, seals, sea lions and other animals such as deer, bears, birds and fish.
Over the years, Holder vigorously defended Marineland against protests and complaints by animal welfare activists who maintain it should be shut down.
Marineland was charged with 11 counts of animal cruelty following an investigation by the Ontario Society for the Prevention of Cruelty to Animals, but all of them were dropped by the Crown in 2017.
In response, the theme park sued the OSPCA, alleging the organization targeted the theme park to boost fundraising and appease animal activists.