scholarly journals Home ground advantage: Local Atlantic salmon have higher reproductive fitness than dispersers in the wild

2019 ◽  
Vol 5 (2) ◽  
pp. eaav1112 ◽  
Author(s):  
Kenyon B. Mobley ◽  
Hanna Granroth-Wilding ◽  
Mikko Ellmen ◽  
Juha-Pekka Vähä ◽  
Tutku Aykanat ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Atlantic Salmon ◽  
Local Adaptation ◽  
Spatial Scales ◽  
Juvenile Fish ◽  
Natural Populations ◽  
Parentage Analysis ◽  
Population Divergence ◽  
Natal Habitat ◽  
In The Wild

A long-held, but poorly tested, assumption in natural populations is that individuals that disperse into new areas for reproduction are at a disadvantage compared to individuals that reproduce in their natal habitat, underpinning the eco-evolutionary processes of local adaptation and ecological speciation. Here, we capitalize on fine-scale population structure and natural dispersal events to compare the reproductive success of local and dispersing individuals captured on the same spawning ground in four consecutive parent-offspring cohorts of wild Atlantic salmon (Salmo salar). Parentage analysis conducted on adults and juvenile fish showed that local females and males had 9.6 and 2.9 times higher reproductive success than dispersers, respectively. Our results reveal how higher reproductive success in local spawners compared to dispersers may act in natural populations to drive population divergence and promote local adaptation over microgeographic spatial scales without clear morphological differences between populations.

scholarly journals Home ground advantage: selection against dispersers promotes local adaptation in wild Atlantic salmon

2018 ◽  
Author(s):  
Kenyon B. Mobley ◽  
Hanna Granroth-Wilding ◽  
Mikko Ellmen ◽  
Juha-Pekka Vähä ◽  
Tutku Aykanat ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Atlantic Salmon ◽  
Local Adaptation ◽  
Spatial Scales ◽  
Juvenile Fish ◽  
Natural Populations ◽  
Parentage Analysis ◽  
Population Divergence ◽  
Natal Habitat ◽  
Scale Population

AbstractA long-held, but poorly tested, assumption in natural populations is that individuals that disperse into new areas for reproduction are at a disadvantage compared to individuals that reproduce in their natal habitat, underpinning the eco-evolutionary processes of local adaptation and ecological speciation. Here, we capitalize on fine-scale population structure and natural dispersal events to compare the reproductive success of local and dispersing individuals captured on the same spawning ground in four consecutive parent-offspring cohorts of wild Atlantic salmon (Salmo salar). Parentage analysis conducted on adults and juvenile fish showed that local females and males had 9.6 and 2.9 times higher reproductive success than dispersers, respectively. Our results reveal how dispersal disadvantage in reproductive success may act in natural populations to drive population divergence and local adaptation over microgeographic spatial scales without clear morphological differences or physical barriers to gene flow.

scholarly journals Captive-bred Atlantic salmon released into the wild have fewer offspring than wild-bred fish and decrease population productivity

2020 ◽  
Vol 287 (1937) ◽  
pp. 20201671
Author(s):  
Ronan James O'Sullivan ◽  
Tutku Aykanat ◽  
Susan E. Johnston ◽  
Ger Rogan ◽  
Russell Poole ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Natural Populations ◽  
Mixed Population ◽  
Lifetime Reproductive Success ◽  
Wild Relative ◽  
Offspring Survival ◽  
Wild Populations ◽  
Annual Productivity ◽  
In The Wild ◽  
Analyse Data

The release of captive-bred animals into the wild is commonly practised to restore or supplement wild populations but comes with a suite of ecological and genetic consequences. Vast numbers of hatchery-reared fish are released annually, ostensibly to restore/enhance wild populations or provide greater angling returns. While previous studies have shown that captive-bred fish perform poorly in the wild relative to wild-bred conspecifics, few have measured individual lifetime reproductive success (LRS) and how this affects population productivity. Here, we analyse data on Atlantic salmon from an intensely studied catchment into which varying numbers of captive-bred fish have escaped/been released and potentially bred over several decades. Using a molecular pedigree, we demonstrate that, on average, the LRS of captive-bred individuals was only 36% that of wild-bred individuals. A significant LRS difference remained after excluding individuals that left no surviving offspring, some of which might have simply failed to spawn, consistent with transgenerational effects on offspring survival. The annual productivity of the mixed population (wild-bred plus captive-bred) was lower in years where captive-bred fish comprised a greater fraction of potential spawners. These results bolster previous empirical and theoretical findings that intentional stocking, or non-intentional escapees, threaten, rather than enhance, recipient natural populations.

scholarly journals Natural selection acts on Atlantic salmon major histocompatibility (MH) variability in the wild

2007 ◽  
Vol 274 (1611) ◽  
pp. 861-869 ◽  
Author(s):  
Elvira de Eyto ◽  
Philip McGinnity ◽  
Sofia Consuegra ◽  
Jamie Coughlan ◽  
Jarle Tufto ◽  
...  
Keyword(s):  
Natural Selection ◽  
Atlantic Salmon ◽  
Balancing Selection ◽  
Natural Populations ◽  
Class Ii ◽  
Major Histocompatibility ◽  
Genotype Frequencies ◽  
Fitness Consequences ◽  
In The Wild ◽  
Class Ii Alpha

Pathogen-driven balancing selection is thought to maintain polymorphism in major histocompatibility (MH) genes. However, there have been few empirical demonstrations of selection acting on MH loci in natural populations. To determine whether natural selection on MH genes has fitness consequences for wild Atlantic salmon in natural conditions, we compared observed genotype frequencies of Atlantic salmon ( Salmo salar ) surviving in a river six months after their introduction as eggs with frequencies expected from parental crosses. We found significant differences between expected and observed genotype frequencies at the MH class II alpha locus, but not at a MH class I-linked microsatellite or at seven non-MH-linked microsatellite loci. We therefore conclude that selection at the MH class II alpha locus was a result of disease-mediated natural selection, rather than any demographic event. We also show that survival was associated with additive allelic effects at the MH class II alpha locus. Our results have implications for both the conservation of wild salmon stocks and the management of disease in hatchery fish. We conclude that natural or hatchery populations have the best chance of dealing with episodic and variable disease challenges if MH genetic variation is preserved both within and among populations.

scholarly journals Reproductive success in wild and hatchery male coho salmon

2015 ◽  
Vol 2 (8) ◽  
pp. 150161 ◽  
Author(s):  
Bryan D. Neff ◽  
Shawn R. Garner ◽  
Ian A. Fleming ◽  
Mart R. Gross
Keyword(s):  
Reproductive Success ◽  
Coho Salmon ◽  
Female Mate Choice ◽  
Parentage Analysis ◽  
Offspring Survival ◽  
The Third ◽  
Factors Influencing ◽  
Hierarchical Position ◽  
In The Wild ◽  
Mixed Groups

Salmon produced by hatcheries have lower fitness in the wild than naturally produced salmon, but the factors underlying this difference remain an active area of research. We used genetic parentage analysis of alevins produced by experimentally mixed groups of wild and hatchery coho salmon ( Oncorhynchus kisutch ) to quantify male paternity in spawning hierarchies. We identify factors influencing paternity and revise previously published behavioural estimates of reproductive success for wild and hatchery males. We observed a strong effect of hierarchy size and hierarchy position on paternity: in two-male hierarchies, the first male sired 63% (±29%; s.d.) of the alevins and the second male 37% (±29%); in three-male hierarchies, the first male sired 64% (±26%), the second male 24% (±20%) and the third male 12% (±10%). As previously documented, hatchery males hold inferior positions in spawning hierarchies, but we also discovered that hatchery males had only 55–84% the paternity of wild males when occupying the same position within a spawning hierarchy. This paternity difference may result from inferior performance of hatchery males during sperm competition, female mate choice for wild males, or differential offspring survival. Regardless of its cause, the combination of inferior hierarchical position and inferior success at a position resulted in hatchery males having only half (51%) the reproductive success of wild males.

scholarly journals Space use and its effects on reproductive success of anadromous Atlantic salmon

2016 ◽  
Vol 73 (10) ◽  
pp. 1461-1471 ◽  
Author(s):  
Cédric Tentelier ◽  
Nicolas Larranaga ◽  
Olivier Lepais ◽  
Aurélie Manicki ◽  
Jacques Rives ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Atlantic Salmon ◽  
Home Range ◽  
Space Use ◽  
Parentage Analysis ◽  
First Year ◽  
Radio Tracking ◽  
Female Reproductive Success ◽  
Second Year ◽  
Individual Features

We combined habitat mapping, radio tracking of adults, redd mapping, and genetic parentage analysis on juveniles for 2 consecutive years to test eight predictions on the reproductive payoffs and individual features associated with space use tactics of anadromous Atlantic salmon (Salmo salar) in a natural population. Regarding payoffs, we found that (1) males settled in better habitat, visited more redds, and tended to get more mates than males settled in poorer habitat; (2) they also sired more offspring; (3) the latter effect was stronger in the first year, when redds were more aggregated; and (4) female reproductive success increased with habitat quality in their home range, especially in the first year. For individual features, (5) individuals that settled earlier in their home range had better habitat for juvenile production, but only in the first year; (6) females were less mobile than males, especially in the second year; (7) larger males did not settle in better habitats than smaller males; and (8) smaller males were not more mobile than larger males.

scholarly journals Variance in the reproductive success of flat oyster Ostrea edulis L. assessed by parentage analyses in natural and experimental conditions

2010 ◽  
Vol 92 (3) ◽  
pp. 175-187 ◽  
Author(s):  
D. LALLIAS ◽  
N. TARIS ◽  
P. BOUDRY ◽  
F. BONHOMME ◽  
S. LAPÈGUE
Keyword(s):  
Reproductive Success ◽  
Genetic Differentiation ◽  
Adult Population ◽  
Natural Populations ◽  
Skewed Distribution ◽  
Ostrea Edulis ◽  
Experimental Conditions ◽  
In The Wild ◽  
Flat Oyster ◽  
Variance In Reproductive Success

SummaryIn order to document further the phenomena of variance in reproductive success in natural populations of the European flat oyster Ostrea edulis, two complementary studies based on natural and experimental populations were conducted. The first part of this work was focused on paternity analyses using a set of four microsatellite markers for larvae collected from 13 brooding females sampled in Quiberon Bay (Brittany, France). The number of individuals contributing as the male parent to each progeny assay was highly variable, ranging from 2 to more than 40. Moreover, paternal contributions showed a much skewed distribution, with some males contributing to 50–100% of the progeny assay. The second part of this work consisted of the analysis of six successive cohorts experimentally produced from an acclimated broodstock (62 wild oysters sampled in the Quiberon Bay). Allelic richness was significantly higher in the adult population than in the temporal cohorts collected. Genetic differentiation (Fst estimates) was computed for each pair of samples and all significant values ranged from 0·7 to 11·9%. A limited effective number of breeders (generally below 25) was estimated in the six temporal cohorts. The study gives first indications of the high variance in reproductive success as well as a reduced effective size, not only under experimental conditions but also in the wild. Surprisingly, the pool of the successive cohorts, based on the low number of loci used, appeared to depict a random and representative set of alleles of the progenitor population, indicating that the detection of patterns of temporal genetic differentiation at a local scale most likely depends on the sampling window.

scholarly journals Chromosomal fusion and life history-associated genomic variation contribute to within-river local adaptation of Atlantic salmon

2018 ◽  
Author(s):  
Kyle Wellband ◽  
Claire Mérot ◽  
Tommi Linnansaari ◽  
J. A. K. Elliott ◽  
R. Allen Curry ◽  
...  
Keyword(s):  
Population Structure ◽  
Atlantic Salmon ◽  
Local Adaptation ◽  
Spatial Scales ◽  
Genetic Relationships ◽  
Snp Array ◽  
Summer Precipitation ◽  
Genomic Variation ◽  
Chromosome 9 ◽  
Adaptive Processes

AbstractChromosomal inversions have been implicated in facilitating adaptation in the face of high levels of gene flow, but whether chromosomal fusions also have similar potential remains poorly understood. Atlantic salmon are usually characterized by population structure at multiple spatial scales; however, this is not the case for tributaries of the Miramichi River in North America. To resolve genetic relationships between populations in this system and the potential for known chromosomal fusions to contribute to adaptation we genotyped 728 juvenile salmon using a 50K SNP array. Consistent with previous work, we report extremely weak overall population structuring (Global FST = 0.004) and failed to support hierarchical structure between the river’s two main branches. We provide the first genomic characterization of a previously described polymorphic fusion between chromosomes 8 and 29. Fusion genomic characteristics included high LD, reduced heterozygosity in the fused homokaryotes, and strong divergence between the fused and the unfused rearrangement. Population structure based on fusion karyotype was five times stronger than neutral variation (FST = 0.019) and the frequency of the fusion was associated with summer precipitation supporting a hypothesis that this rearrangement may contribute local adaptation despite weak neutral differentiation. Additionally, both outlier variation among populations and a polygenic framework for characterizing adaptive variation in relation to climate identified a 250 Kb region of chromosome 9, including the gene six6 that has previously been linked to age-at-maturity and run-timing for this species. Overall our results indicate that adaptive processes, independent of major river branching, are more important than neutral processes for structuring these populations.

scholarly journals Hybridization rapidly reduces fitness of a native trout in the wild

2009 ◽  
Vol 5 (3) ◽  
pp. 328-331 ◽  
Author(s):  
Clint C. Muhlfeld ◽  
Steven T. Kalinowski ◽  
Thomas E. McMahon ◽  
Mark L. Taper ◽  
Sally Painter ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Cutthroat Trout ◽  
Biodiversity Loss ◽  
Parentage Analysis ◽  
Genetic Introgression ◽  
Negative Effects ◽  
Oncorhynchus Clarkii ◽  
Hybrid Swarms ◽  
In The Wild ◽  
Genomic Extinction

Human-mediated hybridization is a leading cause of biodiversity loss worldwide. How hybridization affects fitness and what level of hybridization is permissible pose difficult conservation questions with little empirical information to guide policy and management decisions. This is particularly true for salmonids, where widespread introgression among non-native and native taxa has often created hybrid swarms over extensive geographical areas resulting in genomic extinction. Here, we used parentage analysis with multilocus microsatellite markers to measure how varying levels of genetic introgression with non-native rainbow trout ( Oncorhynchus mykiss ) affect reproductive success (number of offspring per adult) of native westslope cutthroat trout ( Oncorhynchus clarkii lewisi ) in the wild. Small amounts of hybridization markedly reduced fitness of male and female trout, with reproductive success sharply declining by approximately 50 per cent, with only 20 per cent admixture. Despite apparent fitness costs, our data suggest that hybridization may spread due to relatively high reproductive success of first-generation hybrids and high reproductive success of a few males with high levels of admixture. This outbreeding depression suggests that even low levels of admixture may have negative effects on fitness in the wild and that policies protecting hybridized populations may need reconsideration.

Present Status of the Salmonids Atlantic Salmon and Sea-Trout in the Dutch Part of the River Rhine

1994 ◽  
Vol 29 (3) ◽  
pp. 37-41 ◽  
Author(s):  
W. G. Cazemier
Keyword(s):  
Atlantic Salmon ◽  
Salmo Trutta ◽  
Natural Populations ◽  
River Rhine ◽  
Sea Trout ◽  
The Past ◽  
The North ◽  
Trout Population ◽  
The North Sea ◽  
Heavy Pollution

In the past, the anadromous salmonids, Atlantic salmon (Salmo salar) and sea-trout (Salmo trutta), have formed natural populations in the river Rhine. From the beginning of the nineteenth century onwards, the greater part of the drainage area of the river has been gradually altered from a more or less rural and agricultural area, into a highly industrialised one with subsequent industrialisation, river-engineering and heavy pollution. These developments are considered to be the major cause for the disappearance of the populations of anadromous salmonid fish in the 1950s. The water quality has recovered significantly during the past 25 years. From about 1975 onwards, this process gave rise to a recovery of the anadromous trout population. Results of recent studies of the sea-trout migration pattern are presented. They reveal that nowadays these salmonids can complete their up- and downstream migrations from the North Sea to places, situated at hundreds of kilometres upward the river and vica versa. The numbers of recorded Atlantic salmon and catch locations in inland waters are presented. They show a significant increase since 1989. These phenomena can be understood as promising signs of the recovery of the Rhine aquatic ecosystem.

Implications of temporal and spatial scale for Atlantic salmon (Salmo salar) research

1998 ◽  
Vol 55 (S1) ◽  
pp. 9-21 ◽  
Author(s):  
Carol L Folt ◽  
Keith H Nislow ◽  
Mary E Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Multiple Scales ◽  
Spatial Scales ◽  
Effective Means ◽  
Research Strategies ◽  
Atlantic Salmon Salmo Salar ◽  
Temporal And Spatial ◽  
And Migration ◽  
Dependent Processes

The Atlantic salmon (Salmo salar) is a model species for studying scale issues (i.e., the extent, duration, and resolution of a study or natural process) in ecology. Major shifts in behavior and habitat use over ontogeny, along with a relatively long life span and large dispersal and migration distances, make scale issues critical for effective conservation, management, and restoration of this species. The scale over which a process occurs must be linked to the research design and we illustrate this with a discussion of resource tracking by Atlantic salmon. Identifying scale inconsistencies (e.g., when a process is evident at one scale but not another) is shown to be an effective means by which some scale-dependent processes are understood. We review the literature to assess the temporal and spatial scales used in Atlantic salmon research and find most current studies appear to sacrifice spatial and temporal extent for increased resolution. Finally, we discuss research strategies for expanding the temporal and spatial scales in salmon research, such as conducting multiple scales studies to elucidate scale inconsistencies, identifying mechanisms, and using techniques and approaches to generalize across studies and over time and space.

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