Genetic Stock Structure of Western Alaska Chum Salmon and a Comparison with Russian Far East Stocks

1994 ◽  
Vol 51 (S1) ◽  
pp. 84-94 ◽  
Author(s):  
Richard L. Wilmot ◽  
Rebecca J. Everett ◽  
William J. Spearman ◽  
Ramone Baccus ◽  
Natalya V. Varnavskaya ◽  
...  

Substantial genetic divergence was found among chum salmon (Oncorhynchus keta) populations collected from North America and Russia. Five major groups of populations can be identified by geographic region: (1) lower Yukon River summer run; (2) upper Yukon River fall run; (3) Bristol Bay area; (4) Alaska Peninsula; and (5) Russia. Mean heterozygosities were 0.064, 0.062, 0.065, 0.064, and 0.063, respectively; and the percent polymorphic loci values at the 0.99 level were 33.7, 31.3, 32.6, 30.6, and 30.9%, respectively. The hierarchical gene diversity analysis showed that 95.42% of the diversity can be explained by heterogeneity within sites, 1.36% among sites, 0.49% between Yukon River run timing, 1.69% among areas, and 1.04% among countries. The Alaska Peninsula populations are genetically more similar to populations from Russia than to those from western Alaska, and two populations from the upper Yukon River are distinct from other nearby populations. Possible reasons for these findings concern the complex glacial histories of the watersheds.


2011 ◽  
Vol 37 (1) ◽  
pp. 42-51 ◽  
Author(s):  
K. I. Afanas’ev ◽  
G. A. Rubtsova ◽  
M. V. Shitova ◽  
T. V. Malinina ◽  
T. A. Rakitskaya ◽  
...  


1994 ◽  
Vol 51 (6) ◽  
pp. 1430-1442 ◽  
Author(s):  
Eric B. Taylor ◽  
Terry D. Beacham ◽  
Masahide Kaeriyama

We examined geographic variability in minisatellite DNA in chum salmon (Oncorhynchus keta) from 42 populations from the North Pacific Ocean to (1) determine the extent of regional population structure at minisatellite loci and (2) assess the ability of minisatellite variability to determine the geographic origin in individual chum salmon. Restriction fragments from 1.6 to 13.6 kilobase pairs in molecular weight were resolved with a minisatellite probe. The fragments were inherited from parent to offspring and appeared to represent segregation at two linked loci. Minisateliite DNA variability was negligible between annual samples from the same rivers, and chum salmon fell into three regional population groupings: (i) Japanese, (ii) Russian/Yukon River, and (iii) southeastern Alaska/British Columbia salmon. These regional groupings probably reflect historical patterns of postglacial dispersal of chum salmon from three distinct refugia in the North Pacific. We used restriction fragment counts as input to linear discriminant and neural network classification of independent test samples of salmon. Accuracies of 90–95, 81–86, and 72–80% were achieved when classifying fish as of either Japan/Russia/Yukon River versus southeastern Alaska/British Columbia origin, Japan versus Russia/Yukon River origin, or Russia versus Yukon River origin, respectively.



1998 ◽  
Vol 55 (7) ◽  
pp. 1748-1758 ◽  
Author(s):  
Kim T Scribner ◽  
Penelope A Crane ◽  
William J Spearman ◽  
Lisa W Seeb

Although the number of genetic markers available for fisheries research has steadily increased in recent years, there is limited information on their relative utility. In this study, we compared the preformance of different "classes" of genetic markers (mitochondrial DNA (mtDNA), nuclear DNA (nDNA), and allozymes) in terms of estimating levels and partitioning of genetic variation and of the relative accuracy and precision in estimating population allocations to mixed-stock fisheries. Individuals from eight populations of fall-run chum salmon (Oncorhynchus keta) from the Yukon River in Alaska and Canada were assayed at 25 loci. Significant differences in mitochondrial haplotype and nuclear allele frequencies were observed among five drainages. Populations from the U.S.-Canada border region were not clearly distinguishable based on multilocus allele frequencies. Although estimates of total genetic diversities were higher for the DNA loci (Ht = 0.592 and h = 0.647 for nDNA and mtDNA, respectively) compared with protein allozymes (Ht = 0.250), estimates of the extent of population differentiation were highly concordant across marker classes (mean theta = 0.010, 0.011, and 0.016 for allozymes, nDNA, and mtDNA, respectively). Simulations of mixed-stock fisheries composed of varying contributions of U.S. and Canadian populations revealed a consistent bias for overallocation of Canadian stocks when expected Canadian contributions varied from 0 to 40%, due primarily to misallocations among genetically similar border populations. No single marker class is superior for differentiating populations of this species at the spatial scale examined.



2005 ◽  
Vol 62 (7) ◽  
pp. 1570-1579 ◽  
Author(s):  
Jeffrey F Bromaghin ◽  
Penelope A Crane

Fishery resources are often studied when individuals from multiple stocks are aggregated. For that reason, mixed-stock analysis (MSA), i.e., estimation of the stock composition of a mixture of individuals, is an important component of many research programs. Although many characteristics can be used in MSA, DNA loci, particularly microsatellites, have become extremely common. Microsatellite loci usually have a greater number of potential expressions, or alleles, than other marker types. A high degree of polymorphism can enhance the power of MSA, but allele proportions are estimated less precisely and rare alleles are absent or observed in very small numbers in typically sized samples. The reduced precision and presence of rare alleles can degrade the performance of some analytic methods. Although the effect can be reduced by binning alleles, which is common, an objective method of doing so has not been available previously. We present a method for binning alleles that reduces the number of rare alleles, largely preserves the genetic relationships observed among stocks, and modestly improves the performance of mixed-stock and individual-assignment analyses. The method is illustrated with data from Yukon River chum salmon (Oncorhynchus keta) and western Alaska Dolly Varden (Salvelinus malma).



1985 ◽  
Vol 42 (3) ◽  
pp. 437-448 ◽  
Author(s):  
Terry D. Beacham ◽  
Ruth E. Withler ◽  
Allan P. Gould

We used electrophoresis to examine genetic variability of 33 chum salmon (Oncorhynchus keta) stocks in southern British Columbia and used differences in genotypic frequencies among these stocks for estimating stock compositions in a weekly fishery in upper Johnstone Strait. Seven polymorphic loci were used for stock identification. Chum salmon from the Fraser River, Bute and Toba inlets, Vancouver Island, and the southern Mainland had significantly different allelic frequencies, but there was also significant heterogeneity in allelic frequencies at some loci within each region. Allelic frequencies were generally stable over a 2-yr period in nine stocks for which consecutive annual sampling was conducted. There was no significant two-locus linkage disequilibrium for the chum salmon stocks surveyed. Cluster analysis indicated that Fraser River and Bute and Toba Inlet stocks were distinctive, but Vancouver Island and Mainland stocks were not. The timing and relative abundance of Fraser River chum salmon in upper Johnstone Strait as estimated by electrophoretic analysis was confirmed by an in-river test fishery in the Fraser River.



2019 ◽  
pp. 51-53
Author(s):  
Genevieve Johnson ◽  
Christine Kondzela ◽  
Jacqueline Whittle ◽  
Katharine Miller ◽  
Jeffrey Guyon


2008 ◽  
Vol 65 (9) ◽  
pp. 2026-2042 ◽  
Author(s):  
Jeffrey B. Olsen ◽  
Blair G. Flannery ◽  
Terry D. Beacham ◽  
Jeffrey F. Bromaghin ◽  
Penelope A. Crane ◽  
...  

We used 20 microsatellite loci to compare genetic diversity and patterns of isolation-by-distance among three groups of chum salmon ( Oncorhynchus keta ) from two physically distinct watersheds in western Alaska, USA. The results were consistent with the hypothesis that gene flow decreases as the complexity of the hydrographic system increases. Specifically, higher gene flow was inferred among 11 populations from a nonhierarchical collection of short coastal rivers in Norton Sound compared with 29 populations from a complex hierarchical network of inland tributaries of the Yukon River. Within the Yukon River, inferred gene flow was highest among 15 summer-run populations that spawn in the lower drainage, compared with 14 fall-run populations that spawn in the upper drainage. The results suggest that the complexity of the hydrographic system may influence population connectivity and hence the level of genetic diversity of western Alaska chum salmon. Finally, evidence of isolation-by-time, when controlling for geographic distance, supported the hypothesis that genetic divergence in Yukon River chum salmon is influenced by seasonal run timing. However, evidence of isolation-by-distance, when controlling for season run timing, indicated the populations are not sufficiently isolated, spatially or temporally, to prevent gene flow. Dispersal among summer- and fall-run populations may play a role in maintaining genetic diversity.



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