Director Gabriela Cowperthwaite recently told the New York Times that she approached her documentary Blackfish as a journalist with an open mind. The resulting film, which is about killer whales in captivity (specifically at SeaWorld and focusing on the 32-year-old orca Tilikum, who's killed three people), is nonetheless damning enough that it reads like animal liberation propaganda. We hear numerous testimonials from former SeaWorld trainers on the negative effects of keeping these giant, sensitive creatures penned. We see hidden-camera footage of SeaWorld guides feeding park guests incorrect information about orcas' lifespans and fins — the dorsal fins of captive killer routinely collapse, or flop to the side, which is rare in the wild. We see footage of brutal whale-on-human attacks. We hear nothing from SeaWorld itself.

(The corporation's general counsel told the Times that SeaWorld declined to be interviewed for the film "because they doubted the material would be used in good faith." SeaWorld also declined interviews for David Kirby's book Death at SeaWorld, which was released last year.)

The film is not all straightforward condemnation – it highlights the irony at the heart of the anti-captivity movement. If SeaWorld hadn't offered the general public an up-close look at these animals that were previously misunderstood as killing machines, killer whales wouldn't have captured the sympathy of so many humans. It was largely through orca captivity that humans learned just how harmful captivity can be. The film spends a lot of time on former trainers' accounts of bonding with these animals. Captivity may be widely denounced by scientists, and it may produce behavior that we just don't see in the wild. For example, there have been two recorded human attacks by killer whales in the wild; in 2006 ABC reported that there had been nearly two dozen in captivity. However, the human-whale shared experience is not without joy, and Blackfish reasonably documents that.

Last weekend, SeaWorld sent out an email blast to critics countering eight points raised in Blackfish. (Noticeably absent from their responses was the fact that SeaWorld employees lie about dorsal fin collapse to its visitors - in the film, we see hidden camera footage of a tour guide claiming that dorsal fin collapse occurs in "25 percent" of orcas. The figure for wild orcas is actually less than one percent, while almost all captive orcas exhibit it, particularly males. This is believed to occur as a result of their limited swim space and inability to work up to their natural speeds.) The filmmakers responded with counterarguments to SeaWorld's counterarguments. I wanted a sense of perspective from an expert, so I reached out to Debbie Giles, a research biologist who has studied orcas for about 20 years. Right now she is finishing her Ph.D. at the University of California-Davis. She's stationed at San Juan Island, off the coast of Washington.

Giles hadn't seen Blackfish when I spoke to her this week, and told me that she was just responding to my questions "with her gut." She is firmly anti-captivity and has protested at marine parks. She says that SeaWorld offered to fund her research, and that she turned them down, not wanting to be associated with the organization. I asked her generally why she is against killer whale captivity, and this was her response:

Killer whales are social animals [resident killer whales stay with their mothers for life]. That's a really, really important thing with killer whales because you don't see it with other animals. Maybe in some human societies you have both brother and sister staying with mother their entire life, but you don't see it in the wild, you don't see it in other animals. The social aspect of them is what I love to study here looking at these groups. To have a healthy individual it has to be allowed to be in its natural environment and the captive environment is so unnatural that it surpasses any benefit that we might get from having animals in captivity. We are changing their nature so dramatically in order for us to see a pretty thing, because really that's what that boils down to. We're not seeing the actual animal anymore when we see it in captivity, it's a different sort of beast. They're just too amazing, they're just too complex to sacrifice.

I asked Giles why we should be more alarmed at the captivity of orcas than of any other wild animal in a zoo.

"Well just by the nature as aquatic animals, to take them out of the aquatic environment and put them in essentially a terrestrial environment," she explained. "In that regard, I think you could make a hierarchy of which is the worst animal to have in captivity. There is also the social component, and then just the fact that these animals really do swim really far every day. They might be going back and forth but if you were to clock it, it would be miles. The whales in SeaWorld float. They might swim in a circle really fast to get speed up to breach or something, but that's not swimming. Something like a cheetah would be another incredibly sad animal to have a in a zoo. They run, that's what they do, that's what they were built to do."

I went through the rebuttals and rebuttals to the rebuttals – in every case, Giles agreed with the filmmakers. You can read all of those here. Select points that Giles' biological expertise helped expand are below:

SeaWorld Assertion 2: "The assertion that killer whales in the wild live more than twice as long as those living at SeaWorld. While research suggests that some wild killer whales can live as long as 60 or 70 years, their average lifespan is nowhere near that. Nor is it true that killer whales in captivity live only 25 to 35 years. Because we’ve been studying killer whales at places like SeaWorld for only 40 years or so, we don’t know what their lifespans might be—though we do know that SeaWorld currently has one killer whale in her late 40s and a number of others in their late 30s."

Film Response: "In the wild, average lifespan is 30 for males, 50 for females. Their estimated maximum life span is 60-70 years for males and 80-90 years for females. In captivity, most orcas die in their teens and 20s and only a handful have made it past 35.The annual mortality or death rate for orcas is 2.5 times higher in captivity than it is in the wild. These are not controversial data. In the film, we depict what seems to be a deliberate attempt by SeaWorld to misrepresent these well documented data to their visitors."

Giles adds: "Based on photographs we have a whale out here that is supposedly 102 years old. Even if she's not 102 years old, easily she's into her 80s, probably more like 90s. There is no reason to doubt the photo. We had a male die a couple of years ago, who was in his 60s."

SeaWorld Assertion 3: "The implication that unlike killer whales in the wild, killer whales in zoos or parks—and specifically Tilikum, the whale involved in Dawn Brancheau’s death—are routinely bullied by other whales. The word “bullying” is meaningless when applied to the behavior of an animal like a killer whale. Whales live in a social setting with a dominance hierarchy, both at SeaWorld and in the wild. They express dominance in a variety of ways, including using their teeth to 'rake' other whales, in the open ocean as well as in parks."

Film Response: "SW does not show an understanding of basic behavioral biology in this statement. It is true that social animals like orcas do have dominance hierarchies and they are maintained via behavioral interactions. The film asserts that in the wild, whales can also flee conflict. Whales at SeaWorld cannot escape from a negative social interaction and are therefore confronted with conflicts that have proven to be injurious and even fatal. Furthermore in the wild, these hierarchies are among family groups and are maintained with minimal aggression. In the wild, no orca has ever been known to seriously injure or kill another orca, inside or outside of their social group, in any interaction. Certainly minor injuries occur, and scars may remain (including nicks in dorsal fins and scratches on saddles), but no serious injury inflicted on one wild orca by another orca has ever been recorded, when observing live animals or in examining dead ones."

Giles adds: "You do see rake marks in the killer whales in the wild, but it's not repeated. When I've seen it, it heals very quickly. Until I started thinking about whales in captivity, I've never viewed rake marks in wild killer whales as being anything dangerous. It seems very superficial. You might see a rake mark in June when they come back in and by the end of that month you can't tell where the rake mark is. It's just very superficial like a scratch mark down an arm. What you see in captivity is nothing like that.

"The whole idea of putting whales into the tank with other eco-types of killer whales is very bizarre too to me. The idea of putting a naturally born mammal-eater in a tank with a fish-eater, you just never see those two groups intermingling in the wild. Right where I work, they have overlapping territories. You can occasionally see transients across the water and residents say, over here, so you can see them, but they never intermingle. And most of the time the transients actually leave the area when the residents whales come back in, which is interesting, because you think that they'd be top-of-the-food-chain or whatever, but there is no aggressive behavior between the two groups and there is no mating. It's like we're messing with something that we can't even begin to understand and then the whales have these interactions in captivity that are really unhealthy for them."

SeaWorld Assertion 4: "The accusation that SeaWorld callously breaks up killer whale families. SeaWorld does everything possible to support the social structures of all marine mammals, including killer whales. It moves killer whales only when doing so is in the interest of their long-term health and welfare. And despite the misleading footage in the film, the only time it separates unweaned killer whale calves from their mothers is when the mothers have rejected them."

Film Response: "The calf-mother separations that are mentioned in the film both involve two of the most responsible and bonded mothers in SeaWorld’s collection, both of whom have had multiple calves taken from them. The separations are said to be driven primarily by introducing new breeding options to other SeaWorld parks and by fulfilling entertainment and other husbandry needs. We are surprised that SeaWorld has brought up calf rejection, an issue the film does not address and a phenomenon that is extremely rare in wild orcas. In the wild, females generally have their first calf around 13-16 years of age. Because SeaWorld has bred their females as early as 5-6 years of age, these females have not learned proper social behavior, they have not learned how to mother a calf, and may ultimately reject and injure their calves."

Giles adds: "[SeaWorld's response] is nonsense — a mother at SeaWorld should have all of her offspring with her. And we know that's not true. And, let me respond one more thing, with regard to breeding, you would never have inbreeding the way that they do inbreeding with captive killer whales. You wouldn't see that in the wild where mothers and sons are breeding and producing offspring. You know what you end up seeing in the wild is females that are starting to approach that age or breeding, you tend to see them with a bunch of calves, like they'll take on this nanny position and they'll hang out with other females calves, which is probably a nice respite for the mom, so these females that are coming of age, it's documented, it's commonly known that's what ends up happening that they become the babysitters. And that's preparing them to be good moms."

SeaWorld Assertion 5: "The accusation that SeaWorld mistreats its killer whales with punishment-based training that’s designed to force them to learn unnatural behaviors. SeaWorld has never used punishment-based training on any of its animals, including Tilikum, only positive reinforcement. And the behaviors it reinforces are always within the killer whale’s natural range of behaviors."

Film Response: "Again, we are unsure whether SeaWorld has undertaken a careful review of Blackfish. The film never depicts SeaWorld as using punishment. We are confident the trainers would not acquiesce to such overt tactics. Yet although these accounts are not depicted in the film, multiple trainers are aware of incidents where animals may be fed substandard amounts of fish before VIP shows to encourage their cooperation or where a male killer whale might be put in with a group of whales who have been previously aggressive with him in order to encourage complicit behavior. We find the claim that SeaWorld killer whales perform behaviors 'within the killer whale’s natural range of behaviors,' to be false. Wild killer whales are never observed performing front flips or vertical jumps to touch objects, neither have they been observed to spin 360 degrees on land. A killer whale supporting a human who rides, 'surfs,' or leaps from the animal's rostrum does not fall within a wild killer whale’s repertoire either. These are unnatural, trained behaviors only observed in marine parks and reinforced by food."

Giles adds: "Killer whales in Argentina partially beach themselves to grab seals off of the beach, but they don't sit there and arch their back and beach themselves in the way that killer whales in captivity are made to do. It's got to be fairly uncomfortable for them to be out of the water like that, they're such huge animals, and the pressure of being out of water would be incredible, so now you're not going to see that."

Finally, I asked Giles if she knows any biologists who are pro-cap. Surprisingly, she told me that she does.

"I know probably a couple that would argue for it, but they would argue it from a research perspective," she explained. "I don't know if they would argue it from the perspective that it's educational, for example, to the general public. They would argue [that] to have beluga, dolphin, bottle nose dolphin, killer whale, etc., in captivity gives us an opportunity to study, I don't know, respiration or metabolism or pregnancy stuff or stuff like that. But it would be interesting to see if they were specifically asked about educating the public what their stance would be on that. They're able to parse it out, whereas to me, it doesn't matter what we learn from captive killer whales, it's not the same animal.

"You can study respiration rates in captive killer whales and it's going to be very different form what you see in wild killer whales. Even gestation, pregnancy stuff, is ultimately probably very different. How long they can hold their breath. You can't test a captive killer whale and say well killer whales can only hold their breath for this many minutes. Because that killer whale in captivity hasn't had to hold its breath for X amount of time. We aren't going to know anything about metabolism or food consumption, I don't think because the killer whales in captivity are being fed a very, very artificial diet and all the vitamins and everything that the captives have to have just to stay alive, you're not going to have that here. The only argument I've been able to make in my own mind is that [captivity] served a purpose at a time but we're past that now. Now we know that we don't have to fear that in the wild and we can stop shooting at them. Okay, so some killer whales had to die in captivity to get the general public to understand that, now we know that, now the time is done. We should be evolving past this."