94th ESA Annual Meeting (August 2 -- 7, 2009)

SYMP 12-4 - Evaluating the genetic consequences of assisted migration

Wednesday, August 5, 2009: 9:10 AM
Galisteo, Albuquerque Convention Center
Julie R. Etterson, Biology, University of Minnesota-Duluth, Duluth, MN
Background/Question/Methods

Assisted migration as a proactive strategy is intended to ameliorate the negative effects of climate change on native biota by human-mediated translocation of organisms.  The primary motivation for human intervention is the fear that, as climate changes, population fitness will decline and extinction risk will increase because populations no longer experience the climate to which they are adapted.  Assisted migration is controversial because it conflicts with prevailing paradigms in conservation biology that prioritize the preservation of local biodiversity and advocate the use of local genetic material for reintroduction or habitat restoration.Results/Conclusions

This seminar will evaluate the potential risks and benefits of assisted migration from a genetic point of view.  In particular, the genetic implications of a decision not to facilitate movement of organisms will be compared to other strategies including movement of: 1) threatened and/or endangered populations only, 2) populations at the migratory front, 3)  populations at the trailing edge of the range, 4) populations within the current range, and5) various combinations of the above.  The seminar will include a discussion about how far populations should be moved and what genetic material should be moved (i.e. single vs. mixed populations).  The potential impacts assisted migration on the transplanted populations, the recipient community, and the genetic structure of the species as a whole will be examined in light of information already available from the published literature.  While assisted migration may enhance the survival of populations with climate change, especially in cases where populations are already small and/or are under strong selection, it comes with risks of outbreeding depression, loss of genetic identity of populations, and possible risk of inadvertently creating invasions.  In addition, many practical issues limit the feasibility of assisted migration.  I will conclude with a discussion of major gaps in our knowledge that prevent biologists from making informed decisions about the risks of assisted migration.