Data from: Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua

Accurate prediction of species distribution shifts in the face of climate change requires a sound understanding of population diversity and local adaptations. Previous modeling has suggested that global warming will lead to increased abundance of Atlantic cod (Gadus morhua) in the ocean around Greenland, but the dynamics of earlier abundance fluctuations are not well understood. We applied a retrospective spatiotemporal population genomics approach to examine the temporal stability of cod population structure in this region and to search for signatures of divergent selection over a 78-year period spanning major demographic changes. Analyzing >900 gene-associated single nucleotide polymorphisms in 847 individuals, we identified four genetically distinct groups that exhibited varying spatial distributions with considerable overlap and mixture. The genetic composition had remained stable over decades at some spawning grounds, whereas complete population replacement was evident at others. Observations of elevated differentiation in certain genomic regions are consistent with adaptive divergence between the groups, indicating that they may respond differently to environmental variation. Significantly increased temporal changes at a subset of loci also suggest that adaptation may be ongoing. These findings illustrate the power of spatiotemporal population genomics for revealing biocomplexity in both space and time and for informing future fisheries management and conservation efforts.SNP_infoThis tab-separated file contains a complete list of the SNPs analyzed in the study. For each SNP we provide the linkage group and specific linkage map position (where available), the accession reference ID (dbSNP), the original publication for the SNP discovery (source), and any miscellaneous notes.Individual_info_and_genotypesThis tab-delimited file contains information on the sampling location and time, the available demographic data, and the observed SNP genotypes for all individuals analyzed in the study. See the readme file for descriptions of the variables. In the updated file, the weight data for the Icelandic samples have been corrected from grams to kilograms, and number-based sex encoding for these same samples have been changed to M and F. For the Icelandic samples the maturity key used is as follows: 1 is a resting fish, 2-6 indicates a maturing fish, >6 (e.g. 22) means actively spawning.Genepop_GreenlandIcelandCanadaThe SNP genotype data from file "Individual_info_and_genotypes.txt" presented in Genepop format.EnvironmentalData_GreenlandThis tab-delimeted file contains the environmental data used in the BayEnv analysis of environment-allele frequency correlations. See the readme file for details