Kenneth C. Balcomb III
- Copyright 1995
- Center for Whale Research
- Friday Harbor, WA 98250
"Over the years that dolphins have been kept in captivity, some have been released back into the wild after varying periods of time. During most of these early dolphin reintroductions, the animals were often taken from a tank and placed back in the bays close to the facilities. Some of these were display animals no longer of use to the facility. In all these cases there was no followup monitoring." (Bassos, 1993).
This document is dedicated to "Keiko", "Junior", "Tanouk" and "Lolita" , as well as the many smaller captive cetaceans which have been and are maintained in solitary confinement and inadequate facilities devoid of significant educational benefit to the public or conservation benefit to their species. They could be returned to the benefit of all.
For this preliminary summary, I have included anecdotal reports of releases of dolphins (including large species such as killer whales) from captivity by institutions and individuals which have maintained them in many parts of the world. I have also included a few examples of reintroductions of stranded cetaceans which provide useful background on followup documentation. But, it is not the astonishing durability and survival instinct of these animals in nature that is in question. Currently, a major point of contention in the issue of release or reinstatement of captive cetaceans is whether the dolphin or whale will readapt to catching live prey after it has been fed piecemeal in prolonged captivity. Another point of contention is whether released animals will spread acquired pathogens to the wild community, or have sufficient immunity from pathogens in the wild. And, a third point concerns the question of whether a released cetacean will readapt socially, or be condemned to a life of loneliness.
These points must be responsibly addressed; but, if post-captive release is lethal, dangerous and irresponsible, then why has it been done so many times by organizations that are generally considered responsible?
This is not intended to be an exhaustive list, and any additions or suggestions the reader can offer will be appreciated. Considering the worldwide, sometimes illegal and often unregulated trade in these animals, there undoubtedly have been other releases for institutional and business convenience which are not included herein. In the interest of proper historical documentation, I will list only those which have been published or have been reported to me firsthand by reliable sources. This does not include reports of approximately 20 dolphins that have been rehabilitated from stranding events and released back to the wild (NMFS records). It will be particularly useful in future editions of this publication to compile a list of releases of cetaceans that were examined by qualified veterinarians prior to release, and for which veterinary records (and/or specimen materials) may be available. This information, together with similarly compiled information from stranding events may yield useful epidemiological insights into the question of immunocompetence and introduction of 'captive acquired pathogens' to wild populations. The state of the art in telemetry and observational studies can in many cases reveal whether released animals fare well and are socially reinstated.
In the case of non-native introductions, DNA techniques may now be employed in studies of the host populations to reveal additional information concerning the genetic ramifications of non-native releases (eg. in The Bahamas Tursiops truncatus population; or in operational releases such as done by the U.S. Navy, other navies, and swim programs).
Whatever one's view on captivity may be, it is in the interest of humanitarian treatment of those animals which are no longer suitable for display, etc., to seriously examine release and reinstatement to the wild as an option for their retirement. In this respect, the genetic and immunological issues are important and should be objectively addressed; but, in a very real sense they represent spilt milk due to the common past practices of institutions the public has entrusted with the care of marine mammals.
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