Evidence?
Ask and ye shall receive.
This is a study done comparing exact measurements of captive versus both Northern Resident and Southern Resident Orcas showing mortality, birthrate, birthing age, etc.
If you are able to read the metrics, the data lines up exactly between all the populations - including captive.
Comparisons of life-history parameters between free-ranging and captive killer whale (Orcinus orca) populations for application toward species management | Journal of Mammalogy
I've been following this thread for some time, and while agree there has been a lot of juvenile language, poor grammar and reasoning, faulty logic, and emotional outbursts without much factual support, I did feel the need to answer this post:
I can and did read the metrics (I was an ecology/evolutionary biology major and wrote a thesis focusing on statistical error in population biology) and think you have to take this study with a grain of salt. As the author points out, "Life expectancy cannot be determined from the data for any of the populations as the oldest known-age animals are still living." Given that life expectancy is one of the key statistics at issue in many of the grievances of PETA/Blackfish producers/other opponents against Sea World, I don't think this study establishes much. The only metrics that can be compared are of the mortality rates of "known-age animals" in the wild with those of captivity. Given the extremely small sample size of captive specimens, I'm not overly comfortable with extrapolating too much from them. And, in the interest of fairness, look at the authors' affiliations:
Todd R. Robeck*, Kevin Willis, Michael R. Scarpuzzi and Justine K. O’Brien
SeaWorld and Busch Gardens Reproductive Research Center, SeaWorld Parks and Entertainment, 2595 Ingraham Road, San Diego, CA 92019, USA (TRR, JKO)
Minnesota Zoo, 13000 Zoo Boulevard, Apple Valley, MN 55124, USA (KW)
SeaWorld San Diego, 500 SeaWorld Drive, San Diego, CA 92019, USA (MRS)
Not, perhaps, the most unbiased souls in this particular debate.
As for my own personal biases:
I am a zoo-lover, and would consider myself far more aligned with the AZA than with PETA. I grew up within 20 minutes of the now-gone Sea World Ohio, loved going there as I grew up, worked there for two summers during college, and became friends with many of the trainers who worked with the orcas and other animals. I've followed the controversy over Sea World for some time, long before Blackfish premiered, and have found that my opinion has changed over time. I have seen Sea World change its focus over time and through different owners. And I'm thoroughly convinced that the way Sea World keeps it orcas in captivity is wrong and that Sea World should discontinue its captive breeding and end its orca program once the current individuals die out. I am not someone who believes that the whales should (or indeed can) be humanely be returned to the wild, but thoroughly believe that the whales are being bred and kept solely for profit. While I think there is some value in allowing people to glimpse and see this magnificent species, the way the animals are kept and managed in captivity does not, to my mind, cancels that out. And the premise that Sea World's orca shows is based on the showcasing of natural behavior and focusing on educating the public about the whales is, to my mind, rather insulting. Most troubling is the company's mantra when it comes to facts about the whales and the many instances I've both seen and read where facts are misrepresented or, in some cases, blatantly lied about. The attempts to build better exhibits for the whales are, in one sense, a great development, but sadly, to my mind, they represent the sad attempt of a company to justify its continued breeding program and its continued use of the whales to bolster its bottom line. To my mind, orcas are one of those oceanic species, like most cetaceans and larger meat-eating sharks to name a few, that we cannot currently keep well in captivity. That's not to say that we could never keep them well, but I'd like to see better dolphin husbandry and exhibitry be developed/perfected before I could ever stand behind the continued captive holding of orcas. I, for one, find it telling that there are (to my knowledge) no non-profit organizations that continue to attempt to breed orcas.
The saddest thing about this thread and much of the debate over orcas in the wake of Blackfish is that many take the position that one's thoughts on orcas in captivity and Sea World policies in general necessarily equate to an agreement with the PETA stance on captivity in general (or even all of PETA's claims related to orcas in captivity). Count me as a strong supporter of zoos in general with strong reservations about the continued keeping of orcas by Sea World or any other organization, at least in the way the species is currenly being kept.