The influence of hydrographic structure and seasonal run timing on genetic diversity and isolation-by-distance in chum salmon (Oncorhynchus keta)

2008 ◽  
Vol 65 (9) ◽  
pp. 2026-2042 ◽  
Author(s):  
Jeffrey B. Olsen ◽  
Blair G. Flannery ◽  
Terry D. Beacham ◽  
Jeffrey F. Bromaghin ◽  
Penelope A. Crane ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Chum Salmon ◽  
Isolation By Distance ◽  
Geographic Distance ◽  
Population Connectivity ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
Yukon River ◽  
Run Timing

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.

Impacts of supplementation: genetic diversity in supplemented and unsupplemented populations of summer chum salmon (Oncorhynchus keta) in Puget Sound (Washington, USA)

2009 ◽  
Vol 66 (8) ◽  
pp. 1216-1229 ◽  
Author(s):  
Maureen P. Small ◽  
Ken Currens ◽  
Thom H. Johnson ◽  
Alice E. Frye ◽  
Jennifer F. Von Bargen
Keyword(s):  
Genetic Diversity ◽  
Chum Salmon ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Puget Sound ◽  
Oncorhynchus Keta ◽  
Effective Population ◽  
Brood Stock ◽  
Census Size ◽  
Chum Salmon Oncorhynchus Keta

In supplementation programs, hatcheries employ wild-origin fish as brood stock and their offspring are allowed into wild spawning areas. Resource managers use supplementation to support imperiled salmonid populations, seeking to increase census size and possibly effective population size (Ne), while minimizing risks of genetic diversity loss and domestication from hatchery intervention. Here we document impacts of 5–10 years of supplementation on threatened summer-run chum salmon ( Oncorhynchus keta ) in Hood Canal (HC) and Strait of Juan de Fuca (SJF) in Washington State and compare them genetically with unsupplemented summer- and fall-run chum salmon from HC and South Puget Sound. Microsatellite allele frequencies identified four run-timing and geographic groups. HC and SJF summer chum salmon genetic relationships followed a metapopulation pattern of isolation by distance, similar to patterns prior to supplementation, suggesting that supplementation minimally impacted population structure. In most supplemented subpopulations, we detected no effects on diversity and Ne, but high variance in individual pairwise relatedness values indicated over-representation of family groups. In two subpopulations, hatchery impacts (decreased diversity and lower Ne) were confounded with extreme bottlenecks. Rebounds in census sizes in all subpopulations suggest that general survivorship has improved and that possible hatchery effects on genetic diversity will be overcome.

scholarly journals Correlation Between Geographic Distance and Genetic Distance in Populations of Chum Salmon Oncorhynchus keta

1982 ◽  
Vol 48 (12) ◽  
pp. 1703-1709 ◽  
Author(s):  
Akihiro KIJIMA ◽  
Yoshihisa FUJIO
Keyword(s):  
Genetic Distance ◽  
Chum Salmon ◽  
Geographic Distance ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta

DNA and allozyme markers provide concordant estimates of population differentiation: analyses of U.S. and Canadian populations of Yukon River fall-run chum salmon (Oncorhynchus keta)

1998 ◽  
Vol 55 (7) ◽  
pp. 1748-1758 ◽  
Author(s):  
Kim T Scribner ◽  
Penelope A Crane ◽  
William J Spearman ◽  
Lisa W Seeb
Keyword(s):  
Genetic Markers ◽  
Population Differentiation ◽  
Chum Salmon ◽  
Allele Frequencies ◽  
Border Region ◽  
Oncorhynchus Keta ◽  
Mitochondrial Haplotype ◽  
Chum Salmon Oncorhynchus Keta ◽  
Yukon River ◽  
Mixed Stock

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.

Genetic diversity of Asian chum salmon Oncorhynchus keta (Salmonidae, Salmoniformes) and the dynamics of gene pools in Sakhalin populations under artificial reproduction

2008 ◽  
Vol 48 (4) ◽  
pp. 313-325 ◽  
Author(s):  
E. A. Salmenkova ◽  
V. T. Omel’chenko ◽  
K. I. Afanas’ev ◽  
G. A. Rubtsova
Keyword(s):  
Genetic Diversity ◽  
Chum Salmon ◽  
Oncorhynchus Keta ◽  
Gene Pools ◽  
Artificial Reproduction ◽  
Chum Salmon Oncorhynchus Keta

Genetic diversity and gene flow patterns in two riverine plant species with contrasting life-history traits and distributions across a large inland floodplain

2020 ◽  
Vol 68 (5) ◽  
pp. 384
Author(s):  
William Higgisson ◽  
Dianne Gleeson ◽  
Linda Broadhurst ◽  
Fiona Dyer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Structure ◽  
Water Resource ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Geographic Distance ◽  
Resource Development ◽  
Water Resource Development ◽  
Floodplain River

Gene flow is a key evolutionary driver of spatial genetic structure, reflecting demographic processes and dispersal mechanisms. Understanding how genetic structure is maintained across a landscape can assist in setting conservation objectives. In Australia, floodplains naturally experience highly variable flooding regimes that structure the vegetation communities. Flooding plays an important role, connecting communities on floodplains and enabling dispersal via hydrochory. Water resource development has changed the lateral-connectivity of floodplain-river systems. One possible consequence of these changes is reduced physical and subsequent genetic connections. This study aimed to identify and compare the population structure and dispersal patterns of tangled lignum (Duma florulenta) and river cooba (Acacia stenophylla) across a large inland floodplain using a landscape genetics approach. Both species are widespread throughout flood prone areas of arid and semiarid Australia. Tangled lignum occurs on floodplains while river cooba occurs along rivers. Leaves were collected from 144 tangled lignum plants across 10 sites and 84 river cooba plants across 6 sites, on the floodplain of the lower and mid Lachlan River, and the Murrumbidgee River, NSW. DNA was extracted and genotyped using DArTseq platforms (double digest RADseq). Genetic diversity was compared with floodplain-river connection frequency, and genetic distance (FST) was compared with river distance, geographic distance and floodplain-river connection frequency between sites. Genetic similarity increased with increasing floodplain-river connection frequency in tangled lignum but not in river cooba. In tangled lignum, sites that experience more frequent flooding had greater genetic diversity and were more genetically homogenous. There was also an isolation by distance effect where increasing geographic distance correlated with increasing genetic differentiation in tangled lignum, but not in river cooba. The distribution of river cooba along rivers facilitates regular dispersal of seeds via hydrochory regardless of river level, while the dispersal of seeds of tangled lignum between patches is dependent on flooding events. The genetic impact of water resource development may be greater for species which occur on floodplains compared with species along river channels.

scholarly journals Fine-scale sampling reveals distinct isolation by distance patterns in chum salmon (Oncorhynchus keta) populations occupying a glacially dynamic environment

2013 ◽  
Vol 15 (1) ◽  
pp. 229-243 ◽  
Author(s):  
E. L. Petrou ◽  
J. E. Seeb ◽  
L. Hauser ◽  
M. J. Witteveen ◽  
W. D. Templin ◽  
...  
Keyword(s):  
Chum Salmon ◽  
Isolation By Distance ◽  
Dynamic Environment ◽  
Oncorhynchus Keta ◽  
Fine Scale ◽  
Chum Salmon Oncorhynchus Keta

scholarly journals Genetic Characterization of Juvenile Chum Salmon (Oncorhynchus keta) Migrating out of the Yukon River Delta

2019 ◽  
pp. 51-53
Author(s):  
Genevieve Johnson ◽  
Christine Kondzela ◽  
Jacqueline Whittle ◽  
Katharine Miller ◽  
Jeffrey Guyon
Keyword(s):  
Chum Salmon ◽  
Genetic Characterization ◽  
River Delta ◽  
Oncorhynchus Keta ◽  
Chum Salmon Oncorhynchus Keta ◽  
Yukon River ◽  
Juvenile Chum Salmon

Homing, Straying, and Gene Flow among Seasonally Separated Populations of Chum Salmon (Oncorhynchus keta)

1994 ◽  
Vol 51 (3) ◽  
pp. 577-588 ◽  
Author(s):  
Ross F. Tallman ◽  
Michael C. Healey
Keyword(s):  
Gene Flow ◽  
Chum Salmon ◽  
Electrophoretic Analysis ◽  
Oncorhynchus Keta ◽  
Temporal Isolation ◽  
Mark Recapture ◽  
Chum Salmon Oncorhynchus Keta ◽  
Biochemical Genetic ◽  
The Difference ◽  
Log Linear

To test the hypothesis that salmonids that stray into established populations can successfully reproduce, we compared the spatial and temporal pattern of return of marked individuals with the pattern of gene flow suggested by electrophoretic analysis in three populations of chum salmon (Oncorhynchus keta) on Vancouver Island. Substantial straying occurred between populations that spawned during the same season. Populations where there was both spatial and temporal isolation in spawning had little straying. Electrophoretic analysis suggested that gene flow was substantially lower than the rate of straying and that it was highest among populations in close geographic proximity. The results of analysis using a log-linear model showed that the probability of discovering an individual stray was dependent on the population sampled and whether one sampled by mark–recapture or using biochemical genetic analysis. We propose that the difference between the rate of straying as measured by mark–recapture and by the analysis of polymorphic enzymes could be accounted for if salmonids straying onto the spawning grounds of established populations of conspecifics had lower reproductive success than fish that return to their natal streams.

Cutthroat Trout: Evolutionary Biology and Taxonomy

2018 ◽  
Author(s):  
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Rainbow Trout ◽  
Evolutionary Biology ◽  
Isolation By Distance ◽  
Cutthroat Trout ◽  
Population Connectivity ◽  
Oncorhynchus Clarkii ◽  
Habitat Alterations ◽  
Coastal Cutthroat Trout

<em>Abstract</em>.—We examined patterns of dispersal and colonization after Cordilleran glaciations, population connectivity, levels of genetic diversity, and potential impacts of anthropogenic changes to Coastal Cutthroat Trout <em>Oncorhynchus clarkii clarkii</em>. Populations were mostly small with restricted dispersals but exchanged one to two migrants per generation on average. Genetic differences among local populations of Coastal Cutthroat Trout accounted for approximately three-fourths of the total genetic variation among groups, with differences among different geographical groups accounting for the rest. Because of this, hierarchical geographical population structure was difficult to detect except at small geographical scales that reflected local dispersal and gene flow or at broad geographical scales that reflected divergence associated with long-term isolation during Cordilleran glacial advances. Evolutionary processes such as gene flow and genetic drift reflected in isolation by distance occurred at distances up to 600–700 km but mostly lesser distances, whereas divergence associated with Pleistocene glaciation occurred at 1,900 km or greater. Glacial refugia existed south of the Salish Sea along the Washington, Oregon, and California coasts; in the Haida Gwaii or Alexander Archipelago; and possibly near the central coast of British Columbia near Bella Coola. Throughout the range, hybridization with Rainbow Trout <em>O. mykiss </em>or steelhead (anadromous Rainbow Trout) appears to occur naturally at low levels, but releases of hatchery-produced <em>O. mykiss </em>can lead to higher levels of hybridization and rarely hybrid swarms. Degraded habitat may contribute to hybridization, but most anthropogenic habitat alterations reduce habitat quantity and quality and disrupt opportunities for dispersal, contributing to declines in abundance, population connectivity, and genetic diversity.

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