Stability of population structure and genetic diversity across generations assessed by microsatellites among sympatric populations of landlocked Atlantic salmon ( Salmo salar L.)

1999 ◽  
Vol 8 (2) ◽  
pp. 169-179 ◽  
Author(s):  
NATHALIE TESSIER ◽  
LOUIS BERNATCHEZ
2010 ◽  
Vol 67 (2) ◽  
pp. 225-242 ◽  
Author(s):  
Friso P. Palstra ◽  
Daniel E. Ruzzante

Studying population structure and gene flow patterns on temporal scales facilitates an evaluation of the consequences of demographic, physical, and environmental changes on the stability and persistence of populations. Here, we examine temporal genetic variation within and among Atlantic salmon ( Salmo salar ) rivers in Newfoundland and Labrador, Canada, using samples collected over a period of six decades (1951–2004). Our objective was to evaluate temporal changes in population connectivity associated with the closure of a commercial marine fishery. Despite demographic instability, we find that population structure remained temporally stable over more than 50 years. However, age structure can affect results when not taken into consideration, particularly in populations of large effective size where genetic drift is not strong. Where weak signals of genetic differentiation did not complicate analyses, contemporary migration was often asymmetric, yet low, suggesting patterns of intermittent gene flow. Nevertheless, we find some links between changes in population dynamics and contemporary gene flow. These findings may therefore imply that management decisions impacting the contemporary population dynamics of individual Atlantic salmon rivers can also affect the genetic stability of this species as a whole.


1989 ◽  
Vol 67 (6) ◽  
pp. 1453-1461 ◽  
Author(s):  
E. Verspoor ◽  
L. J. Cole

Atlantic salmon (Salmo salar) from Little Gull Lake on the Gander River system of central Newfoundland were found to be electrophoretically polymorphic at 5 of 20 protein loci screened. Four of the polymorphic loci were structural and one was regulatory. Major heterozygote deficiencies relative to Castle–Hardy–Weinberg expectations were detected at the two most polymorphic loci, Aat-3 and Mdh-3,4, and significant nonrandom associations between genotypes at these loci and the other polymorphic loci, Sdh-1, Me-2, and Pgm1-t, were also found. The heterozygote deficiencies and the nonrandom genotype associations were attributable to the admixture of genetically distinct gene pools of resident and anadromous salmon in the lake. This is the first documented case of coexistence of reproductively separated populations of Atlantic salmon of the two life history types, and shows that the sympatric occurrence of the two forms can represent between-population variation.


2012 ◽  
Vol 69 (12) ◽  
pp. 1947-1958 ◽  
Author(s):  
Mikhail Yu. Ozerov ◽  
Alexey E. Veselov ◽  
Jaakko Lumme ◽  
Craig R. Primmer

Combining population genetic and landscape ecology approaches provides an understanding of how environmental factors affect individual dispersal, population size, and structure. We first generated a set of predictions of the expected effect of “riverscape” characteristics on salmonid genetic diversity and divergence, based on the results of earlier research on this topic in salmonid fishes. We then tested these predictions in a data set consisting of the microsatellite data and riverscape characteristics of 39 Atlantic salmon ( Salmo salar ) populations from northwest Russia. The carrying capacity of the river was an important factor shaping the genetic diversity and differentiation of Atlantic salmon populations in the region: salmon in rivers with a larger carrying capacity tended to have higher genetic diversity and lower genetic differentiation. The importance of other riverscape characteristics often varied between anadromous and freshwater populations. Taken together, these associations demonstrate a high and complex level of river landscape influence on the genetic diversity and structure of Atlantic salmon populations and highlight the importance of spawning and nursery area maintenance for the conservation of salmonids.


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