Translocation as a conservation strategy
Hellmann, JJ 2013, in Simon, AL (ed.), Encyclopedia of Biodiversity, vol. 7, Academic Press, Waltham, pp. 236-240.
Throughout history, humans have deliberately moved, or ‘translocated’, plants and animals from one location to another. Recently, translocation has emerged as both a tool for conserving species and, subsequently, a topic of scientific and moral debate. This chapter discusses how and why translocations occur, emerging themes in translocation, and the many risks involved with this conservation strategy.
‘Translocation’ describes the movement of organisms from one area to another. The types of and reasons for translocation are diverse. Reintroduction involves the movement of an organism into an area historically occupied by, but currently void of, that species. Reintroduction is distinct from introduction, which involves the movement of an organism into an area where that species has not been known to occur previously. Koalas have been the subject of introductions in the past, introduced to Westernport Bay, Victoria during the late 1800s and early 1900s to offset the effects of hunting, disease and habitat loss on the source population. The new population was later used as a source population for reintroductions to the mainland. Supplementation is a strategy that involves adding organisms to an existing population, such as to boost numbers or increase population genetic diversity. In the future, translocation may emerge as a strategy to mitigate the effects of contemporary threats on flora and fauna. One such technique that has been discussed is ‘managed relocation’. This technique is a response to the threat of climate change that would involve moving animals from a compromised area to a habitat where climatic conditions remain suitable. Individuals with particular genotypes that are, for example, resistant to particular environmental conditions or diseases may be targeted for translocation.
Several factors may improve the likelihood of translocation being successful. These include managing the original cause of population decline to prevent further declines, including many individuals in the translocation event to minimise the risk of a genetic bottleneck, and managing stakeholder participation and public perceptions to improve the social acceptability of translocation as a conservation tool. On the other hand, there are a number of risks associated with translocation. Ecological risks include overexploiting source populations, disrupting the ecosystem in which the new population is established, and introducing pathogens to naïve populations. Equally important are the risks of economic inefficiency, as translocation costs can be great and, in some cases, even exceed the costs of managing the threat causing population declines in the first place, and ethical considerations about manipulating nature.
While many past translocation attempts can be considered successful against several criteria, there is still a great deal of uncertainty and risk surrounding translocation as a tool for conserving species. Risks in this context are made challenging to manage by the complex nature of both natural and social systems. Although it is unlikely that we could ever predict all of the potential risks of a translocation event, as translocation emerges as an important conservation strategy for the future it is important that we continue to develop protocols for identifying, mitigating and managing risks to the greatest extent possible.
Summarised by Joanna Horsfall
Disclaimer: The summary of this report is provided for reference purposes only and does not represent the findings or opinions contained in the original report. Although every effort has been made to bring forward the main elements of the report, this review is no substitute for the full the report itself. Should you have any concerns or perceive any errors please contact us and we shall endeavour to rectify and improve the review.