SREL Reprint #2105

Translocations and the preservation of allelic diversity

Craig A. Stockwell1, Margaret Mulvey2, and Gary L. Vinyard3 

1Program in Ecology, Evolution and Conservation Biology, and Biological Resources Research Center, Department of Biology,
University of Nevada, Reno, NV 89557, USA
2Savannah River Ecology Laboratory, Drawer E, Aiken, SC 29802, USA
3Department of Biology, University of Nevada, Reno, NV 89557, USA

Abstract: Translocation is a tool commonly used for the conservation of threatened and endangered fish species. Despite extensive use, the biological implications of translocation remain poorly understood. Of particular interest is the effect of translocation on genetic variability. Maintenance of genetic variability in “refuge” populations is assumed to be important for both short- and long-term success. We examined allozyme variability at 16 loci for mosquitofish (Gambusia affinis) populations with known histories of introduction. Refuge populations had significantly lower levels of heterozygosity. Refuge populations also had considerably lower levels of allelic diversity than parental populations. All losses were of relatively rare alleles (frequency less than 0.1 in parental population). These losses were probably due to an undocumented bottleneck early in the introduction history. These results were surprising because the initial transplant involved 900 fish and because mosquitofish have numerous reproductive traits that should minimize the effects of bottlenecks on genetic diversity. A literature review revealed that genetic variability is often reduced in refuge populations, and that such reductions typically involve the loss of alleles. We suggest that translocated populations be examined periodically for losses of genetic variability.

SREL Reprint #2105

Stockwell, C.A., M. Mulvey, and G.L. Vinyard. 1996. Translocations and the preservation of allelic diversity. Conservation Biology 10:1133-1141.

This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).