Fine-scale genetic structure and diversity in native and introduced Arctic charr populations
Abstract
Genetic diversity is a central indicator for assessing the conservation status, since it influences evolutionary processes and demographic dynamics of populations. In fragmented habitats, introduced populations are often genetically impoverished due to founder effects and isolation, potentially leading to reduced population viability. Here, we investigated the genetic structure, diversity and demographic history of native and introduced populations of Arctic charr (Salvelinus alpinus) inhabiting peri-Alpine and Alpine lakes using SNP and microsatellite (STR) markers. Contrary to expectations of genetic erosion from founder effects, most introduced populations displayed moderate levels of genetic diversity, although effective population sizes were variable and often lower than those of native populations. Alpine populations form a heterogeneous genetic mosaic structured into several genetic clusters, reflecting distinct introduction histories and isolation. Historical demographic trajectories indicated a general decline in effective population size, consistent with genetic drift in small and isolated populations. Estimates were significantly correlated between SNPs and STRs, confirming that both marker types provide reliable estimates of population genetic structure. These findings suggest that established introduced populations may contribute to maintaining genetic diversity in threatened species at their thermal margin. However, this should not be interpreted as support for introductions, given the risks of hybridization, introgression and loss of local adaptation. Management strategies need to consider populations individually, as translocations may disrupt genetic structure but could also support the conservation of declining native populations.
Related
- Genetic diversity, population structure, and interspecific differentiation in introduced breeding populations of Eucalyptus sideroxylon and Eucalyptus camaldulensis established in northern Chile.
- Climate‐Associated Genetic Variation in Native and Introduced Populations of Eustenopus villosus, a Biological Control Agent for Yellow Starthistle
- Mitochondrial genome-derived microsatellites reveal genetic diversity and population structure in Callery pear populations
- Country-scale diversity, spatial genetic structure, and mitochondrial demographic history of Aedes aegypti populations in Colombia
- Genetic diversity, phenotypic plasticity, and adaptive capacity of Ziziphus nummularia populations in Iran
BibTeX
@article{rogissart2026finescale,
title = {{Fine-scale genetic structure and diversity in native and introduced Arctic charr populations}},
author = {Hervé Rogissart and Guillaume Evanno and Jean Guillard and Jérôme G Prunier and Martin Daufresne and Jan Baer and Allan Raffard},
journal = {Biological Conservation},
year = {2026},
month = sep,
doi = {10.1016/j.biocon.2026.112115},
url = {https://hal.science/hal-05755741v1},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Fine-scale genetic structure and diversity in native and introduced Arctic charr populations
AU - Hervé Rogissart
AU - Guillaume Evanno
AU - Jean Guillard
AU - Jérôme G Prunier
AU - Martin Daufresne
AU - Jan Baer
AU - Allan Raffard
PY - 2026
DA - 2026/09/18
JO - Biological Conservation
DO - 10.1016/j.biocon.2026.112115
UR - https://hal.science/hal-05755741v1
AB - Genetic diversity is a central indicator for assessing the conservation status, since it influences evolutionary processes and demographic dynamics of populations. In fragmented habitats, introduced populations are often genetically impoverished due to founder effects and isolation, potentially leading to reduced population viability. Here, we investigated the genetic structure, diversity and demographic history of native and introduced populations of Arctic charr (Salvelinus alpinus) inhabiting peri-Alpine and Alpine lakes using SNP and microsatellite (STR) markers. Contrary to expectations of genetic erosion from founder effects, most introduced populations displayed moderate levels of genetic diversity, although effective population sizes were variable and often lower than those of native populations. Alpine populations form a heterogeneous genetic mosaic structured into several genetic clusters, reflecting distinct introduction histories and isolation. Historical demographic trajectories indicated a general decline in effective population size, consistent with genetic drift in small and isolated populations. Estimates were significantly correlated between SNPs and STRs, confirming that both marker types provide reliable estimates of population genetic structure. These findings suggest that established introduced populations may contribute to maintaining genetic diversity in threatened species at their thermal margin. However, this should not be interpreted as support for introductions, given the risks of hybridization, introgression and loss of local adaptation. Management strategies need to consider populations individually, as translocations may disrupt genetic structure but could also support the conservation of declining native populations.
SN - 0006-3207
ER -