Localized Genetic Structure Persists in Wild Populations of Chinook Salmon in the John Day River Despite Gene Flow from Outside Sources

2008 ◽  
Vol 137 (6) ◽  
pp. 1650-1656 ◽  
Author(s):  
Shawn R. Narum ◽  
Terra L. Schultz ◽  
Donald M. Van Doornik ◽  
David Teel
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Chinook Salmon ◽  
Wild Populations ◽  
John Day River ◽  
John Day

Assessing covariability among populations in the presence of intraseries correlation: Columbia River spring-summer chinook salmon (Oncorhynchus tshawytscha) stocks

2000 ◽  
Vol 57 (3) ◽  
pp. 616-627 ◽  
Author(s):  
Louis W Botsford ◽  
Charles M Paulsen
Keyword(s):  
Chinook Salmon ◽  
Degrees Of Freedom ◽  
Oncorhynchus Tshawytscha ◽  
Columbia River ◽  
Data Types ◽  
Natural Logarithm ◽  
Different Types ◽  
John Day River ◽  
One Year ◽  
John Day

We assessed covariability among a number of spawning populations of spring-summer run chinook salmon (Oncorhynchus tshawytscha) in the Columbia River basin by computing correlations among several different types of spawner and recruit data. We accounted for intraseries correlation explicitly in judging the significance of correlations. To reduce the errors involved in computing effective degrees of freedom, we computed a generic effective degrees of freedom for each data type. In spite of the fact that several of these stocks have declined, covariability among locations using several different combinations of spawner and recruitment data indicated no basinwide covariability. There was, however, significant covariability among index populations within the three main subbasins: the Snake River, the mid-Columbia River, and the John Day River. This covariability was much stronger and more consistent in data types reflecting survival (e.g., the natural logarithm of recruits per spawner) than in data reflecting abundance (e.g., spawning escapement). We also tested a measure of survival that did not require knowing the age structure of spawners, the ratio of spawners in one year to spawners 4 years earlier. It displayed a similar spatial pattern.

Advances in Understanding Landscape Influences on Freshwater Habitats and Biological Assemblages

2019 ◽  
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Chinook Salmon ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Cumulative Effect ◽  
River Network ◽  
Dissimilarity Matrix ◽  
Site Specific ◽  
Freshwater Habitats

<i>Abstract.</i>—Habitat fragmentation, land use practices, and flow impediments modify the natural course of rivers, disrupting connectivity and subsequently affecting dispersal and gene flow in aquatic organisms. Many of the relationships between the physical river network and the genetic structure of populations are not well understood. Riverscape genetics is a developing field that uses population genetic metrics to assess genetic structure within the context of the environmental variables that drive functional connectivity in a river network. Here, we applied an effective distance network approach to characterize the effects of hydrology in shaping neutral genetic population structure of fall-run Chinook Salmon <i>Oncorhynchus tshawytscha </i>within a small, coastal Oregon catchment. We evaluated whether gene flow was limited by (1) site-specific features occurring within spawning habitat, using a dissimilarity matrix, and (2) the cumulative effect of the environment accrued while traveling en route between reaches. We found that Chinook Salmon that spawned at higher elevations (site specific effects) after traversing steeper gradients (en-route effects) were more genetically distinct from individuals that traversed gradual gradients and spawned at lower elevations. This effect (isolation by resistance) was distinguishable from isolation by distance, which was not detected among spawning groups. Our study enhanced interpretation of habitat heterogeneity in constraining gene flow and spatial genetic structure among reaches within a small, coastal catchment. Given that smaller catchments may hold life history 36 variation that is important to long-term population persistence, there is need to understand these relationships that maintain genetic diversity.

scholarly journals Genetic structure among wild populations of Elliot's Pheasant Syrmaticus ellioti in China from mitochondrial DNA analyses

2007 ◽  
Vol 17 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Ping Ping Jiang ◽  
Yun Fa Ge ◽  
Qiu Lei Lang ◽  
Ping Ding
Keyword(s):  
Gene Flow ◽  
Genetic Structure ◽  
Mitochondrial Control Region ◽  
Maximum Parsimony Tree ◽  
Wild Populations ◽  
Dna Analyses ◽  
Haplotype Variation ◽  
Control Region Sequences ◽  
Parsimony Tree ◽  
High Level

AbstractGenetic structure among five populations of Elliot's Pheasant sampled from five different provinces – Anhui (AH), Zhejiang (ZJ), Fujian (FJ), Hunan (HN) and Guizhou (GZ) – was assayed using mitochondrial control region sequences from 33 individuals. Using AMOVA, we found a high level of haplotype variation within populations, and a degree of genetic structure among groups (GZ population relative to all others pooled). However, this difference was not statistically significant and little geographical structure was indicated among the remaining populations. Furthermore, using a rooted maximum parsimony tree, we found the sequences of the GZ population were largely grouped in their own branch, while sequences of the other four populations were interspersed among branches. We identified a lower level of gene flow between the GZ population and all others, a finding supported by significant FST values. Conversely, we identified a larger amount of gene flow between the remaining four populations, particularly among the three easternmost populations (AH, ZJ and FJ). Given our results, further study should be focused on the GZ population and on management units for the purpose of maintaining the genetic structure of the species in the west of China.

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