Glacial biogeography of North American coho salmon (Oncorhynchus kisutch)

Abstract

To study the glacial biogeography of coho we examined 20 microsatellite loci and mitochondrial DNA D-loop sequence in samples from Alaska to California. Microsatellite data divided our samples among five biogeographic regions: (1) Alaska and northern coastal British Columbia; (2) the Queen Charlotte Islands; (3) the mainland coast of British Columbia and northern Washington State; (4) the Thompson River; and (5) Oregon and California. The D-loop sequence data suggested three geographical regions: (1) Oregon and California; (2) the Thompson River; and (3) all the other sites north of the southern ice margin. Microsatellite data revealed no difference in the number of alleles in different regions, but mitochondrial DNA data revealed a cline of decreasing diversity from south to north. We suggest that the two signals presented by these different marker types illuminate two time frames in the history of this species. Endemic microsatellite diversity in Alaska and on the Queen Charlotte Islands provides evidence in favour of Fraser Glaciation refugia in these regions. The loss of mitochondrial variation from south to north suggests that one of the earlier, more extensive, Pleistocene glaciations eliminated coho from its northern range.

Comparative landscape genetic analysis of three Pacific salmon species from subarctic North America

“…It is not known if, or to what extent, Pacific salmon occupied the region during glaciation. However, there is evidence some salmon populations in the area may have survived the last glaciation in small numbers (e.g., Smith et al 2001). The general geographic congruence among species r 2 is the posterior mode of unexplained variance associated with each model and the 95% HPDI is the 95 percent highest probability interval.…”

Genetic diversity of Metarhizium anisopliae var. anisopliae in southwestern British Columbia

“…Yukon and Alaska) and to the south (i.e. southern Washington) of BC (Smith et al, 2001). Island biogeography theory indicates that large, continuous zones have more species than small, fragmented zones (MacArthur and Wilson, 1967).…”

Ancient DNA investigation of prehistoric salmon resource utilization at Keatley Creek, British Columbia, Canada

“…As expected for Pacific Northwest salmon populations [46] and for restricted time period from which the samples obtained, low sequence variations were observed for all amplified PCR sequences. Studies of both ancient and modern salmon have suggested that these low levels of genetic diversity may reflect the relatively recent post-glacial recolonization of these species [32,40,44,46]. Only one haplotype was identified within each of the species for the three amplified fragments, with the exception of the Cyt B amplifications of chinook remains which yielded two haplotypes (distinguished by only a single base pair difference e see Figs.…”