Microsatellite variation reveals weak genetic structure and retention of genetic variability in threatened Chinook salmon (Oncorhynchus tshawytscha) within a Snake River watershed

2006 ◽  
Vol 8 (1) ◽  
pp. 133-147 ◽  
Author(s):  
Helen Neville ◽  
Daniel Isaak ◽  
Russell Thurow ◽  
Jason Dunham ◽  
Bruce Rieman
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Snake River ◽  
Microsatellite Variation ◽  
River Watershed

Analysis of microsatellite DNA resolves genetic structure and diversity of chinook salmon (Oncorhynchus tshawytscha) in California’s Central Valley

2000 ◽  
Vol 57 (5) ◽  
pp. 915-927 ◽  
Author(s):  
Michael A Banks ◽  
Vanessa K Rashbrook ◽  
Marco J Calavetta ◽  
Cheryl A Dean ◽  
Dennis Hedgecock
Keyword(s):  
Genetic Structure ◽  
Chinook Salmon ◽  
Microsatellite Dna ◽  
Life Histories ◽  
Oncorhynchus Tshawytscha ◽  
Random Mating ◽  
Central Valley ◽  
Microsatellite Dna Markers ◽  
Maximum Likelihood Methods ◽  
Genetic Structure And Diversity

We use 10 microsatellite DNA markers to assess genetic diversity within and among the four runs (winter, spring, fall, and late fall) of chinook salmon (Oncorhynchus tshawytscha) in California's Central Valley. Forty-one population samples are studied, comprising naturally spawning and hatchery stocks collected from 1991 through 1997. Maximum likelihood methods are used to correct for kinship in juvenile samples and run admixture in adult samples. Through simulation, we determine the relationship between sample size and number of alleles observed at polymorphic microsatellite markers. Most samples have random-mating equilibrium proportions of single and multilocus genotypes. Temporal and spatial genetic heterogeneity is minimal among samples within subpopulations. An FST of 0.082 among subpopulations, however, indicates substantial divergence among runs. Thus, with the exception of our discovery of two distinct lineages of spring run, genetic structure accords with the diverse chinook life histories seen in the Central Valley and provides a means for discrimination of protected populations.

A multiple-reach model describing the migratory behavior of Snake River yearling chinook salmon (Oncorhynchus tshawytscha)

1998 ◽  
Vol 55 (3) ◽  
pp. 658-667 ◽  
Author(s):  
Richard W Zabel ◽  
James J Anderson ◽  
Pamela A Shaw
Keyword(s):  
Chinook Salmon ◽  
Migration Rate ◽  
River Flow ◽  
Oncorhynchus Tshawytscha ◽  
Nonlinear Models ◽  
Columbia River ◽  
River System ◽  
Snake River ◽  
Migration Route ◽  
Time Step

A multiple-reach model was developed to describe the downstream migration of juvenile salmonids in the Columbia River system. Migration rate for cohorts of fish was allowed to vary by reach and time step. A nested sequence of linear and nonlinear models related the variation in migration rates to river flow, date in season, and experience in the river. By comparing predicted with observed travel times at multiple observation sites along the migration route, the relative performance of the migration rate models was assessed. The analysis was applied to cohorts of yearling chinook salmon (Oncorhynchus tshawytscha) captured at the Snake River Trap near Lewiston, Idaho, and fitted with passive integrated transponder (PIT) tags over the 8-year period 1989-1996. The fish were observed at Lower Granite and Little Goose dams on the Snake River and McNary Dam on the Columbia River covering a migration distance of 277 km. The data supported a model containing two behavioral components: a flow term related to season where fish spend more time in regions of higher river velocity later in the season and a flow-independent experience effect where the fish migrate faster the longer they have been in the river.

Population viability of the Snake River chinook salmon (Oncorhynchus tshawytscha)

1995 ◽  
Vol 52 (7) ◽  
pp. 1442-1448 ◽  
Author(s):  
John M. Emlen
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Population Viability ◽  
Snake River ◽  
Management Actions ◽  
Population Dynamics Model ◽  
The Status ◽  
Salmon Population ◽  
Mortality Improvement ◽  
Best Fit

In the presence of historical data, population viability models of intermediate complexity can be parameterized and utilized to project the consequences of various management actions for endangered species. A general stochastic population dynamics model with density feedback, age structure, and autocorrelated environmental fluctuations was constructed and parameterized for best fit over 36 years of spring chinook salmon (Oncorhynchus tshawytscha) redd count data in five Idaho index streams. Simulations indicate that persistence of the Snake River spring chinook salmon population depends primarily on density-independent mortality. Improvement of rearing habitat, predator control, reduced fishing pressure, and improved dam passage all would alleviate density-independent mortality. The current value of the Ricker α should provide for a continuation of the status quo. A recovery of the population to 1957–1961 levels within 100 years would require an approximately 75% increase in survival and (or) fecundity. Manipulations of the Ricker β are likely to have little or no effect on persistence versus extinction, but considerable influence on population size.

scholarly journals Microsatellite variation and population genetic structure of a neotropical endangered Bryconinae species Brycon insignis Steindachner, 1877: implications for its conservation and sustainable management

2009 ◽  
Vol 7 (3) ◽  
pp. 395-402 ◽  
Author(s):  
Cristianne Kayoko Matsumoto ◽  
Alexandre Wagner Silva Hilsdorf
Keyword(s):  
Genetic Structure ◽  
Genetic Variability ◽  
Population Genetic Structure ◽  
Population Genetic ◽  
Food Resource ◽  
Southeastern Brazil ◽  
Captive Population ◽  
Wild Populations ◽  
Isolated Populations ◽  
Microsatellite Variation

Piabanha (Brycon insignis) is a freshwater fish species from the drainages in Southeastern Brazil. During the 1950s, it was an important economic and food resource for local populations, but dramatic and continuous environmental degradation seriously jeopardized the B. insignis populations in the region. Microsatellite markers were used to assess the genetic structure of wild populations of B. insignis and compare the genetic variability and integrity of the wild populations with a captive population. Samples of DNA from 208 specimens from geographically isolated populations were analyzed. Population genetic structure was investigated using F ST, R ST estimates as well as AMOVA. All five loci used in this study were polymorphic with observed heterozygosity ranging from 0.77 (± 0.15) to 0.88 (± 0.07) in the wild population and 0.90 (± 0.09) in the captive population and the allelic richness average were 7.56 (± 0.27) and 5.80 (± 1.02), respectively. Overall genetic differences were significantly partitioned among populations (F ST = 0.072, p = 0.034). Evidence of a genetic bottleneck was found in some of the wild populations, but especially in the captive population. The results showed that genetic variability still can be found in B. insignis populations which are currently structured possibly due to anthropic actions. The implications of these findings for the management and conservation of B. insignis populations are discussed.

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