Population Genetics of Arctic Grayling Distributed Across Large, Unobstructed River Systems

• Published in: Transactions of the American Fisheries Society
• Main Authors: Reilly, Jessica R., Paszkowski, Cynthia A., Coltman, David W.
• Other Authors: Alberta Conservation Association, Natural Sciences and Engineering Research Council of Canada, Canadian Wildlife Federation, Aboriginal Affairs and Northern Development Canada
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2014
• Subjects: Arctic; Athabasca River; Canada; Arctic grayling; Peace River; Thymallus arcticus
• Online Access: http://dx.doi.org/10.1080/00028487.2014.886620; https://afspubs.onlinelibrary.wiley.com/doi/pdf/10.1080/00028487.2014.886620

Abstract We investigated the population genetics of Arctic Grayling Thymallus arcticus distributed throughout several connected river systems in Alberta, Canada. Broad‐ and fine‐scale population structure was examined by genotyping nine microsatellite loci in 1,116 Arctic Grayling captured from 40 sites in the Hay, Peace, and Athabasca River basins. Genetic diversity tended to decline from north to south (allelic richness versus latitude: Spearman's rank correlation r s = 0.793, P < 0.05); the lowest level of diversity was detected in a stocked population. We found significant genetic divergence between and within major river basins (overall genetic differentiation index F ST [ θ ST ] = 0.13) and strong isolation‐by‐distance patterns in the Peace River basin (Mantel's r = 0.97, P < 0.001) and Athabasca River basin (Mantel's r = 0.95, P < 0.001). Evidence for gene flow among sites in neighboring rivers (i.e., 25–100km apart) was common; significant genetic differentiation tended to occur at the subbasin level. The spatial scale of differentiation for Arctic Grayling is intermediate to those reported for other sympatric salmonid species that differ in population size and degree of spawning site fidelity.