batch_auto_20260713 202607131256465730 BOEM ESP geoESPIS ESPIS@boem.gov Bureau of Ocean Energy Management Using Genotyping-by-Sequencing (GBS) Population Genetics Approaches to Determine the Population Structure of Tanner Crab (Chionoecetes bairdi) in Alaska University of Alaska Fairbanks University of Alaska Fairbanks Information on the extent of migration and structure of wild populations is an important consideration in the development of natural resource management policies. Genomic studies can increase our ability to the detect differences in population structure. Until recently, use of such studies was limited by the genomic resources and databases available for a particular species. However, novel and continuously refined sequencing technology offers the potential to circumvent this barrier and provide access to genomic-scale datasets of genetic variation, even for species without available reference genomes. This project focused on developing baseline estimates of the genome-wide variation and population structure of Tanner crab (Chionoecetes bairdi), a commercial species that is important to Alaska’s economy and society. The Tanner crab is targeted in commercial, personal use, and subsistence fisheries in Alaska. Previously strong crab fisheries in Prince William Sound, Kodiak, and the Bering Sea have faced major uncertainties over the past few decades, including declines and mixed recoveries that may be linked to environmental changes and both anthropogenic and biological factors. Here, we attempted to apply genomic sequencing techniques to investigate the population structure of C. bairdi in Alaska, focusing on the connectivity of Cook Inlet and Shelikof Strait populations with populations in Southeast Alaska, Prince William Sound, Kodiak Island, the Alaska Peninsula, the Aleutian Islands, and the Bering Sea shelf. Technical issues limited the sample sizes from Southeast Alaska, Prince William Sound, and the Bering Sea shelf and restricted the geographical regions that could be statistically compared. No significant distinction between regions could be detected based on individuals’ genotypes through measurements of FST or by Principal Components Analysis (PCA). We are continuing to test population structure models and estimates of genome-wide variation and diversity. 25000 U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program https://doi.org/10.13039/100012475 M16AC00011 10.67297/9A1DB0 https://boem.gov/awardpages/100144