REINTRODUCING CAPTIVE DOLPHINS INTO THE WILD
CURRENT DEVELOPMENTS

International Zoo News, Volume 41/3, Number 252.

  1994 © Zoo-Centum - International Zoo News

  Introduction

The captive breeding of wild animals and their reintroduction to the wild is seen as one of the reasons for the existence of modern zoos and aquaria, and as a tool to assist endangered species. Research in this field remains in its infancy, though there have been notable results with, for example, Arabian oryx, red wolf, golden lion tamarin and California condor. Until recently, however, protocols for the reintroduction of marine mammals had not been extensively researched. There have been a number of reintroductions of bottle-nosed dolphin (Tursiops truncatus), but most have not been scientifically documented.

In Britain, the most famous welfare & release was a project called 'Into The Blue'. This obtained three 'redundant animals from U.K. dolphinaria, rehabilitated them and released them off the coast of the Turks and Caicos Islands in the British West Indies. The project was co-ordinated by the animal group Zoo Check (Born Free Foundation) and numerous other animal groups, and funded from an appeal by the British Mail on Sunday newspaper, which raised the sum of £139,000. However, the project was a controversial one and serious scientific concern was expressed regarding the eventual release of the three dolphins into the Caribbean in September 1991. This was due - among other considerations - to the fact that the three animals were not originally from these waters and were, therefore, genetically foreign, making the release an action that went against any current IUCN guidelines on reintroduction. As some I.Z.N. readers may be aware, a documentary of this project, shown on BBC 2 in 1992, was the subject of an investigation by the Broadcasting Complaints Commission, published in October 1993. After investigation, the Commission upheld six of twelve complaints against the programme claiming that it was emotive, inaccurate or misleading.

To date, in fact, there appear to have been only two genuine scientifically controlled release projects for dolphins, one in the United States and the other in Australia. The U.S. project was undertaken by biologists Dr Ken Norris and Dr Randy Wells. Two animals were captured and kept for two years of study, released, and then monitored. Two of the conclusions were that (due to social grouping) young male dolphins were the best candidates for release, and that animals should always be released into the location of their capture.

The Australian project was undertaken by biologist Dr Nick Gales, and was developed to release the dolphins held at Atlantis Marine Park near Perth. However, despite expert advice and care from park staff and international experts, it was found that a number of the animals released did not adjust to the wild and had to be returned to captive management. Dr Gales makes an interesting comment in the concluding section of his published report: It is important to note that this programme was not based on the premise that a dolphin is necessarily better off in the wild than in appropriate conditions in captivity. Rather, there were not any realistic alternatives for this dolphin group beyond a rehabilitation attempt. Releases of dolphins from other facilities in the world will almost certainly occur. However, it may not be the most humane approach for those dolphins, and, if undertaken, should be run as a careful scientific experiment with realistic alternatives for those animals that do not manage the transition.'

The U.S. Navy Report

Current research into this subject culminated in the publication by the U.S. Navy in October 1993 of a comprehensive 86-page study of the current understanding of marine mammal reintroduction. Published as Technical Report 1549, Reintroduction to the Wild as an Option for Managing Navy Marine Mammals (Brill and Friedl, 1993) was produced in response to a Congressional request in November 1991 to 'develop training procedures which allow mammals which are no longer required for this project to be released back into their natural habitat.' The Navy's Research and Development Division which encompasses marine mammal research and husbandry - was funded to undertake a research project to investigate the options and the feasibility of such releases. This involved a review of all available data on reintroducing dolphins: consultation with experts in the reintroduction of wild animals; the convening of a workshop involving experts involved in marine mammals and reintroduction and of a second workshop of the Navy's marine mammal experts to review accumulated data and formulate a model for a marine mammal reintroduction programme.

The first workshop entitled "Exploring the Reintroduction of Captive Marine Mammals" was held in Albuquerque. New Mexico, from 23 to 26 June 1992. It was attended by 28 persons. including Navy scientists and technicians involved in marine mammal husbandry and other recognised experts with scientific credentials in marine mammals, conservation, and the reintroduction of other species- The purpose of the workshop was to construct a hypothetical framework for reintroduction of marine mammals. and to recommend possible paths for effectively implementing such an effort The focus was to be on animal welfare, without reference to any specific programme - including the Navy's. In the hypothetical reintroduction plan which emerged, nine critical components were discussed and evaluated: animal human interactions; behavioural conditioning before reintroduction; criteria for identifying candidate animals; disease transmission and genetics; environmental considerations and requirements; post-introduction tracking and data collection protocols; nutritional requirements and food stocks; social behaviour and natural history: and species-specific requirements.

Three major issues addressed were whether marine mammals can be successfully reintroduced to the wild, whether such reintroduction is appropriate, and what germane issues remain to be addressed or resolved. The participants produced the following answers to these questions:

(1)

 Possibility of Success. The success of reintroducing marine mammals to the wild would depend upon resources, methodologies and technologies which do not currently exist

(2)

 Appropriateness. There is no compelling reason for reintroducing non-endangered species. The closing statements imply that reintroductions conducted to reduce inventories are not warranted unless the associated risks and costs can be resolved. However, they also imply that the resolution of these issues would potentially benefit future reintroduction efforts with endangered marine mammal species.

(3)

 Unresolved issues. Given the data currently available on marine mammals, the benefits of reintroduction to either the animals reintroduced or indigenous populations can neither be predicted nor adequately quantified; the risks of mortality to the animals reintroduced and to the population into which they are inserted cannot be predicted; and the tracking and telemetry technology needed to quantify the success of reintroduction does not exist.

The concerns of the workshop participants are perhaps best represented in the closing statement in Appendix D of the report on the criteria for selecting candidate animals:

"Animal welfare considerations may provide reasons for reintroduction programmes. However, there is no a priori reason to conclude that an animal's health, longevity, and quality of life in the wild will be superior to its health, longevity, and quality of life in a captive environment. The concept of reintroducing marine mammals back to the wild may be a considered alternative in the management of these animals in the event of the need for:

  • the conservation of endangered species.
  • the enhancement of locally depleted stocks of non-endangered species if translocation is not preferable.
  • the occurrence of a lack of adequate management space and/or facilities.
  • an increase in the number of surplus animals as a result of successful breeding programmes.

Even in these cases, reintroduction is not the only management alternative to be considered, and is certainly not always the best. Other alternatives for consideration include:remaining in captivity - the animal stays at the facility in which it has been housed.translocation - the animal is moved to a facility or habitat other than the one it has been maintained in.· euthanasia - ethically and politically undesirable.The development of methodologies and technologies related to reintroduction may enhance the ability to meet the demands imposed by management requirements or conditions stated above. However, the concept of reintroduction requires a fully researched approach and follow-up with documentation such that it contributes to the development of the necessary technologies."

Interestingly, it was calculated that the cost of a five-year pilot study and the subsequent reintroductions of the fifteen U.S. Navy dolphins found eligible for release - a total time-span of between seven and eleven years - would exceed the cost of maintaining the animals throughout their lives (approximately the next 20 years) by a factor of from two to as high as five. It was estimated that the current (1992) cost per year to maintain all 'excess' dolphins in captivity would be two million dollars per year.

Conclusions

The basic conclusions of the report suggest that current technologies cannot support long-term assessment of release Further, that only certain candidate animals, selected on factors such as age and general and genetic health should be considered eligible for reintroduction, even when these technological problems have been solved. Therefore, although development of effective protocols for the reintroduction of dolphins would be useful and worth encouraging as a tool for use in the reintroduction of an endangered species, so-called 'welfare release of animals may not be in the best interest of the individuals released or the population that receives them.

References

Brill, ILL., and Friedl, W.A. (1998): Technical Report 1549:Reintroduction to the Wild as an Option for Managing Navy Marine Mammals. Naval Command, Control and Ocean Surveillance Centre, RDT&E Division, San Diego.

Gales, N., and Waples, K. (1993): The rehabilitation and release of bottlenose dolphins from Atlantis Marine Park, Western Australia. Aquatic Mammals Vol. 19, No. 2

IUCN (1987): The IUCN Position Statement on Translocation of LivingOrganisms: Introductions, Re-introductions and Re-stocking. International Union for the Conservation of Nature, Gland, Switzerland.

 

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