I won't dispute that there may be some health issues in captive cetaceans housed in marine mammal parks. Similar to stereotypic behaviors and some other "idiopathic" pathologies observed in terrestrial carnivorans, captive cetaceans present with some issues of an unknown cause. These are health concerns that you may not find in the wild, but conversely, wild cetaceans can present with pathologies that are not common or may not exist in captive populations.
Some health issues do occur in both free-ranging and captive populations. However, the difference between captive odontocetes, such as killer whales, and their wild counterparts is that theses captive cetaceans have access to medical care and treatment from clinical veterinarians and pathologists board certified in zoo and wildlife medicine (with special training in aquatic animal healthcare and pathology). Some of these veterinary specialists are double boarded in pathology and aquatic animal medicine. Wild marine mammals do not typically have attending clinicians.
So when I learned yesterday, that PETA's "wildlife veterinarian," who graduated from veterinary school in May and completed neither an internship or residency in aquatic animal medicine, had visited SeaWorld San Diego and offered any clinical assessment of the captive residents, I was astounded. In reading the individual's LinkedIn profile, I learned that she participated in a month-long externship in marine mammal medicine and is now touted as an expert in marine mammal clinical medicine and pathology by none other than PETA. I don't think a month- long "workshop" gives someone enough training or credibility to make a scathing report about the health and welfare of animals in a marine park, a zoo, a sanctuary or in the wild. I would be more inclined to listen to someone selling cotton candy behind Shamu Stadium than this individual.
I immediately sought out some data in the literature to refute her findings or at least counter her agenda, which was to slam SeaWorld.
The first study that I encountered following a brief search of the scientific literature suggests that high PCB levels in southern resident killer whales, not only make this orca population among the most contaminated in the world, but that the PCB's in their tissues increases their susceptibility to communicable or infectious diseases, including those infecting other odontocete species, which share their marine habitat. Therefore, to suggest that living free means living healthy couldn't be farther from the truth when it comes to marine mammals.
The study goes on to say that "Regardless of which pathogens are involved, infectious diseases could be a threat to the long-term viability of the southern resident killer whale population. The small size of the population, its highly social structure, and the potential for high PCB levels to increase susceptibility to pathogens, increase this possibility. Efforts need to continue in order to learn more about infectious diseases of free-ranging southern resident killer whales and sympatric odontocetes."
So before you jump on the Blackfish or PETA bandwagon, please consider the source or the credentials of the so-called authorities.