1 Institut de Biologie Intégrative et des Systèmes, Université Laval, Québec, Québec, Canada.
2 Département de Biologie, Université Laval, Québec, Québec, Canada.
3 Department of Biology, Concordia University, Montreal, Québec, Canada.
4 Plateforme de Bio-Informatique de l'IBIS (Institut de Biologie Intégrative et des Systèmes), Université Laval, Québec, Quebec, Canada.
5 National Institute of Biological Resources, Biodiversity Research and Cooperation Division, Incheon, Republic of Korea.
6 Fisheries and Oceans Canada, Arctic and Aquatic Research Division, Freshwater Institute, Winnipeg, Manitoba, Canada.

Single nucleotide polymorphism (SNP) panels are powerful tools for assessing the genetic population structure and dispersal of fishes and can enhance management practices for commercial, recreational and subsistence mixed-stock fisheries. Arctic Char (Salvelinus alpinus), Brook Trout (Salvelinus fontinalis) and Lake Whitefish (Coregonus clupeaformis) are among the most harvested and consumed fish species in Northern Indigenous communities in Canada, contributing significantly to food security, culture, tradition and economy. However, genetic resources supporting Indigenous fisheries have not been widely accessible to northern communities (e.g. Inuit, Cree, Dene). Here, we developed Genotyping-in-Thousands by sequencing (GT-seq) panels for population assignment and mixed-stock analyses of three salmonids, to support fisheries stewardship or co-management in Northern Canada. Using low-coverage Whole Genome Sequencing data from 418 individuals across source populations in Cambridge Bay (Nunavut), Great Slave Lake (Northwest Territories), James Bay (Québec) and Mistassini Lake (Québec), we developed a bioinformatic SNP filtering workflow to select informative SNP markers from genotype likelihoods. These markers were then used to design GT-seq panels, thus enabling high-throughput genotyping for these species. The three GT-seq panels yielded an average of 413 autosomal loci and were validated using 525 individuals with an average assignment accuracy of 83%. Thus, these GT-seq panels are powerful tools for assessing population structure and quantifying the relative contributions of populations/stocks in mixed-stock fisheries across multiple regions. Interweaving genomic data derived from these tools with Traditional Ecological Knowledge will ensure the sustainable harvest of three culturally important salmonids in Indigenous communities, contributing to food security programmes and the economy in Northern Canada.