New Information on Killer Whale Longevity

Last month, SeaWorld announced it was suing California authorities over a ban on breeding killer whales after a lawsuit claiming the marine park attraction deceived patrons was dismissed by a federal judge.  This news came on the heels of more criticism following the untimely death of an 18-year-old killer whale at SeaWorld's San Antonio park.  The cause of death--a fungal infection.

Candida, a yeast, afflicts both captive and free-ranging orca depsite the assertion by animal rights groups that the fungal infection is strictly associated with animals in an oceanarium. Nonetheless, the tragic loss of the captive orca likely generated evocative imagery for those who found the 2013 docudrama Blackfish to be factual. Others found the film to be a gripping motion picture, yet highly sensationalized and innacurate.

Blackfish revisited a human tragedy resulting from an intimate encounter with an apex marine predator in captivity. The film immediately cast a dark shadow over the world's most famous marine park conglomerate and its fallout has been quite damaging for the company and for the marine mammal training industry. The film has been touted as an impactful cinematic treatment of captive cetaceans by marine biologists working in situ and has elicited much conjecture on the part of non-experts regarding the confinement of the world's largest dolphin.  What many argue is that Blackfish wasn't particularly concerned with the science, conservation and rehabilitation programs of SeaWorld parks, which have been instrumental in saving species from endangerment, not to mention the awareness raised through exposing millions of people to animals they won't likely ever see in the wild.
 
SeaWorld shaped our perception of the killer whale, making a villain of the seas what we know of today as our friend Shamu. Through its history of showcasing riveting in-water performances of these majestic marine predators with their trainers, SeaWorld rebranded orca, demonstrating the intimate human-animal bond while dispelling myths and alleviating fears of these cetaceans, which naturally prey on fish and pinnipeds and were hunted by humans for recreation and retribution over perceived threats to people. The utilitarian view of how these sentient beings are treated in captivity, which is consistent with many zoo and marine park professionals, takes under consideration that SeaWorld's nearly 30 killer whales, most of which were captive born, are ambassadors for their species and compared to their wild counterparts face different human stressors, many of which are less life-threatening than what they face in the wild.
 
In terms of of helping wild animals SeaWorld, in collaboration with local, state, and federal agencies has rescued and in many cases rehabilitated 26,000 marine animals. That figure far exceeds what any other zoological facility on the planet can claim.  And despite persistent criticism from organizations like HSUS and PETA, which don't conduct or fund any marine mammal rescue work themselves, SeaWorld's staff continues to be among first responders at the site of any whale strandings on both of our coasts.
 
With regard to the science, SeaWorld and Hubbs-SeaWorld Research Institute have been contributing to research in marine animal ecology and other marine science disciplines for over 5 decades, including work on both captive and free-ranging killer whales.

Dr. Grey Stafford, a former marine mammal trainer at SeaWorld and the incoming president of the International Marine Animal Trainer's Association, recently announced that a publication has been accepted by the journal Marine Mammal Science that questions the scientific work of some of his anti-SeaWorld adversaries.  In this article, Grey and his coauthors, including the lead author, a current SeaWorld researcher, not only refute claims that killer whales live shorter lifespans in captivity than in the wild, but they call into question the integrity of the science conducted by those with an anti-SeaWorld agenda. 
 
In the paper, they respond to claims by Jeffrey Ventre and John Jett who are well-known as outspoken critics of SeaWorld's killer whale programs regarding the longevity of killer whales in captive settings and in the wild. According to Dr. Stafford, the publication, "Captive killer whale (Orcinus orca) survival'', which appeared in the October issue of Marine Mammal Science has mislead the MMS readership and a broader community of marine scientists and enthusiasts with their inappropropriate handling of data, and by making invalid comparisons of data sets.
 
MIT trained biologist Dr. Kelly Jaakkola of Florida's Dolphin Research Center and Dr. Stafford's coauthor said, "They make erroneous assertions and draw unsupported conclusions in the article. Readers of their paper have no prior way of knowing the role both had in the production of Blackfish or their demonstrated opposition to orcas in human care."
 

Dr. Jaakkola said, "In order to make a valid comparison between the survival rates of wild and captive orcas, then, Jett and Ventre should have excluded from their analyses calves that died before the age of six months in BOTH groups (i.e., wild and human care) rather than in just the wild dataset. This is a critical error because scientists estimate neonatal orca mortality in the wild to be quite high (37% to 50% in the paper Jett and Ventre used for their wild comparison). By not following previously accepted scientific methodology for this species, and instead including neonatal deaths (i.e., animals less than six months) in their calculations for captive survival rate, Jett and Ventre significantly underestimated captive survival rates compared to the wild survival rates that necessarily exclude neonatal deaths."

 
Furthermore, Robeck et al. (2015) assert that the authors confuse conventional terminology used to explore and explain quantitative aspects of life history and survivorship data:
 

Dr. Jaakkola said, "For wild studies, the timing of the scientific field season is such that orca calves are not initially seen until they're about 6 months old. This means that survival rates for wild orcas necessarily exclude calves that died before 6 months (estimated at around 43%; not a tiny number). So to make a valid comparison between the survival rates of wild and captive orcas, Jett and Ventre should have excluded from their analyses calves that died before the age of 6 months in BOTH groups, rather than in just the wild dataset. By not using the same rules for both groups, their comparison becomes as absurd (and scientifically invalid) as comparing the heights of two groups of people in which we count only those people above 5'6" in one group, but count people of all heights in the other."
 
In addition, Robeck et al. (2015) note that the authors confuse two very different concepts used to explore and explain aspects of life history and survivorship data: survival probabilities (i.e., the estimated probability of reaching a certain age, which they reported for wild orcas) with population structure (i.e., the proportion of a living population currently in each age bracket, which they reported for orcas in human care). These are very different things. So while it may be correct to state that only 7% of currently living captive female killer whales have reached age 40 (population structure), this is obviously not because 93% died before reaching that age (survival probability) as their discussion implies."

In summary, the authors conveyed that their own institutional affiliations may warrant concern over their scientific objectivity, as they work for zoological facilities. With that said, they invite skeptical readers to examine the data sets themselves, which are publicly available in the aforementioned publications.
 
 
Robeck, T., Jaakkola, K., Stafford G., & Willis, K. (in press). Killer whale (Orcinus orca) survivorship in captivity: A critique of Jett and Ventre (2015). Marine Mammal Science.