Blackfish Directed by Gabriela Cowperthwaite. Rated PG-13. Opens Friday.

In the three decades since he was captured and turned into a performer at SeaWorld, an orca named Tilikum has been connected with the deaths of three people, two of them his own trainers. Blackfish, a documentary advocating the release of all large aquatic mammals, argues that such tragedies are the inevitable result of keeping a huge, migratory, predatory animal in a tiny enclosed space for its entire life. The film features interviews with numerous former SeaWorld trainers, all of whom now maintain that they find the park’s treatment of Tilikum unethical and reprehensible. SeaWorld has responded with a press statement detailing the film’s alleged factual errors, to which the filmmakers have responded in turn; it seems unlikely that the controversy will be settled to anyone’s satisfaction any time soon.

Viewed strictly on its own terms, Blackfish makes some compelling points, but it’s also rhetorically muddled. The film conflates two arguments that are really separate issues: First, that orcas are poorly treated by parks like SeaWorld (which is true, but only to the extent that it’s true of most zoo animals), and second, that orcas are dangerous to their human trainers (which is also true, but shouldn’t be news to anybody who’s ever seen one). Efforts to demonstrate that the second is a direct result of the first—specifically, that Tilikum killed two trainers (20 years apart) because he’d been driven mad by his confinement—are less than persuasive. Maybe it’s wrong for us to keep these majestic creatures locked up for our own amusement, but that’s a larger question about zoos in general—one that this movie seems very leery of raising.