Managed relocation of species: Noah's Ark or Pandora's Box?

"Managed relocation" (MR; also called "assisted migration" or "assisted colonization") is the human-aided movement of species adversity affected by global change where these species cannont move themselves. Goals of MR include, but are not limited to, conservation of biodiversity, reduction of extinction risk, enhancement of evolutionary potential, and maintenance or augmentation of ecosystem services. Recently there has been much talk, in the scientific literature as well as in the press, about the costs and benefits of MR. As a conservation strategy, MR has promise, but it could also have serious collateral costs. For example, MR may succeed in rescuing a given species from extinction, but it may also introduce a species into habitat where it becomes invasive, causing ecosystem disruptions or extinctions of other taxa. A working group met in August 2008, in conjunction with the annual meeting of the ESA, to develop a framework for understanding the degree to which MR could achieve its objectives, the risks that it might incur, and strategies that could be used to implement it.