Population Demographics and Genetic Diversity in Remnant and Translocated Populations of Sea Otters

• Published in: Conservation biology 1999-12, Vol.13 (6), p.1378-1385
• Main Authors: Bodkin, J. L., Ballachey, B. E., Cronin, M. A., Scribner, K. T.
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Conservation biology; Conservation, protection and management of environment and wildlife; Enhydra lutris; Fundamental and applied biological sciences. Psychology; Genetic diversity; Genetics of eukaryotes. Biological and molecular evolution; Haplotypes; Mathematical minima; Otters; Parks, reserves, wildlife conservation. Endangered species: population survey and restocking; Population genetics; Population genetics, reproduction patterns; Population growth; Population growth rate; Population size; Seas; Vertebrata
• ISSN: 0888-8892; 1523-1739
• DOI: 10.1046/j.1523-1739.1999.98124.x

The effects of small population size on genetic diversity and subsequent population recovery are theoretically predicted, but few empirical data are available to describe those relations. We use data from four remnant and three translocated sea otter (Enhydra lutris) populations to examine relations among magnitude and duration of minimum population size, population growth rates, and genetic variation. Mitochondrial (mt)DNA haplotype diversity was correlated with the number of years at minimum population size (rs= -0.741, p = 0.038) and minimum population size (rs= 0.709, p = 0.054). We found no relation between population growth and haplotype diversity, although growth was significantly greater in translocated than in remnant populations. Haplotype diversity in populations established from two sources was higher than in a population established from a single source and was higher than in the respective source populations. Haplotype frequencies in translocated populations of founding sizes of 4 and 28 differed from expected, indicating genetic drift and differential reproduction between source populations, whereas haplotype frequencies in a translocated population with a founding size of 150 did not. Relations between population demographics and genetic characteristics suggest that genetic sampling of source and translocated populations can provide valuable inferences about translocations.