RT Journal Article
T1 Long-term stocking practices threaten the original genetic diversity of the southernmost European populations of Atlantic salmon Salmo salar
A1 Almodóvar Pérez, Ana María
A1 Leal García, María Shaila
A1 Gómez Nicola, María Gracia
A1 Hórreo Escandón, José Luis
A1 García Vázquez, Eva
A1 Elvira Payán, Benigno
AB Many Atlantic salmon Salmo salar populations in Europe are threatened by previous stocking with foreign hatchery strains. Temporal patterns of genetic characteristics of salmon from northern Spain, the southernmost European populations, were compared before and after species decline and heavy stocking with specimens from northern Europe. Eleven microsatellite loci were analysed in archival (scales from 1958-1960) and contemporary (2007-2008) samples from the River Sella. Temporal analyses revealed a similar heterozygosity between archival and contemporary samples, despite a drastic decrease in population abundance, while the contemporary sample showed a higher allelic richness due to the occurrence of foreign alleles. Considering only the alleles with at least 4% frequency in the archival sample, 2 alleles exclusive to the River Sella were absent in the contemporary sample, and 14 alleles showed a decrease of at least 4% frequency. Four alleles common in Scotland showed a high occurrence in the contemporary sample, so they are good candidates as markers of introgression of foreign genes. The heavy stocking with non-native Scottish broodstocks between 1970 and 1990 caused the introgression found in the contemporary sample when compared with the pristine population. An abrupt decrease was evident when the estimates of effective number of breeders were adjusted to take into account overlapping generations (NbAdj), effective population size (NeAdj) estimated from NbAdj, and number of breeders estimated using the sibship assignment method (NbSIB). The very low effective size values found in the contemporary sample, together with the detrimental synergy between genetic drift and high rates of introgression, represent a severe risk for the conservation of native salmon.
PB Inter-Research Science Publisher
SN 1863-5407
YR 2020
FD 2020-03-12
LK https://hdl.handle.net/20.500.14352/128852
UL https://hdl.handle.net/20.500.14352/128852
LA eng
NO Almodóvar, A., Leal, S., Nicola, G. G., Hórreo, J. L., García-Vázquez, E., & Elvira, B. (2020). Long-term stocking practices threaten the original genetic diversity of the southernmost European populations of Atlantic salmon Salmo salar. Endangered Species Research, 41, 303-317. https://doi.org/10.3354/ESR01029
NO This study was funded by the Spanish Ministry of Economy and Competitiveness through the research project CGL2012-36049/BOS. Contemporary samples were provided by Jerónimo de la Hoz (Environmental Agency, Regional Government of Asturias, Spain). We are very grateful to Dr. John Gilbey, who kindly provided us with the microsatellite baseline generated by the SALSEA-Merge Project   (www.nasco.int/sas/salseamerge.htm). All field and laboratory procedures complied with the current laws of Spain. J.L.H. was supported by a Spanish MINECO Juan de la Cierva-Incorporación postdoctoral grant (ref. IJCI-2015- 23618).
NO Ministerio de Economía y Competitividad (España)
DS Docta Complutense
RD 18 dic 2025