There has been much heated debate about the longevity of captive dolphins compared with that of dolphins in the wild. The dolphin captivity industry will often make the claim that dolphins in captivity live just as long, or even longer, than dolphins in nature. According to some of those who are opposed to keeping dolphins captive, the picture looks very different. Just a few examples of mortality statistics provided by members of the animal welfare community:
'Orcas can live up to 90 years in the wild. They live an average of only 5.2 years in captivity'
'Bottlenose dolphins live up to 45 years in the wild. In captivity, they live an average of about 5 years.'
The most obvious problem with these statements, of course, is the fact that they compare maximum life expectancy of wild dolphins with the average lifespan of captive dolphins. Maximum life expectancy and average lifespan are two different values. They can’t be compared as if they were one, and for this reason alone the statistics are misleading.
Furthermore, in order to calculate the average lifespan of captive dolphins one would have to know the exact time of the dolphins' capture or birth, and the exact time of their death. It's simply not possible to gather this information, as it's not made available to us by the dolphin captivity industry. In many countries there is no obligation to report dolphin deaths, nor is it required by law to report how many dolphins died during the capture process.
The most serious error associated with using mortality rates as an argument against dolphin captivity is the fact that it opens the door for dolphinaria to use mortality rates in defense of dolphin captivity. By putting so much emphasis on a captive dolphin's lifespan compared with that of a dolphin in nature, we reduce the dolphin captivity issue to being a question of how long a captive dolphin can be kept alive. The result is a futile dispute that diverts the attention from what this issue is really about. At some point the dolphin captivity industry may be able keep their dolphins alive for as long as in nature, but that doesn't make it right.