There is a lengthy report from 1999 on the Government of Canada web site on the capture and captivity of marine animals in Canada.
Absolute requirements by the public for maintenance of marine mammals in captivity is that both care and welfare of the captive animals is assured, and that there are educational and scientific benefits which result from keeping such animals. Scientific benefits of research on captive marine mammals are well recognized by marine mammalogists and much of the public. However, educational benefits from the publics’ exposure to captive marine mammals are more difficult to demonstrate; lacking is a body of independent empirical studies which shows its impact. Thus, such benefits are questioned by some. More troubling is the fact that there is not adequate authority presently in Canada to regulate the quality of care which animals receive in captivity.
The report mentions Marineland a couple of times, usually like this:
Zoocheck/Canadian Federation of Humane Societies is particularly concerned about conditions at Marineland, specifically the housing for sea lions, use of isolation pools, and the petting of orcas by the public. They strongly argue that petting pools should not be allowed in Canadian aquaria.
The report is 8 years old, and some things have changed since then, but was still interesting to browse through the report.