Using genomic tools to inform management of the Atlantic northern fulmar

Highly migratory species pose unique conservation and management challenges, especially when significant mortality occurs away from breeding concentrations. Population genetics and genomics may help with the appropriate management of these species by (1) determining the population genetic structure of a species across its range, and (2) allowing the assignment of individuals to their breeding source. The northern fulmar (Fulmarus glacialis; Procellariiformes: Procellariidae) is a seabird species that breeds in colonies throughout the North Atlantic and Pacific oceans. This species ranges widely across ocean basins during the non-breeding season and is exposed to a variety of threats throughout the annual cycle. The impact of mortality during the nonbreeding season on individual breeding colonies is unknown but has important ramifications for conservation and management. In this study we used restriction site-associated DNA sequencing (RADseq) to provide 6614 genome-wide single nucleotide polymorphisms (SNPs) to investigate population genetic structure of northern fulmars using 127 individuals from six breeding colonies spanning the Atlantic. Additionally, birds of unknown breeding origin were sampled from two locations: (1) offshore in the Labrador Sea, and (2) the Baffin Bay-Davis Strait region (NAFO subarea 0), as bycatch in gillnets set for Greenland halibut (Reinhardtius hippoglossoides). We found weak genetic differentiation among breeding colonies, which we suggest reflects historical associations as well as contemporary gene flow among populations. Most bycatch birds were likely from nearby breeding colonies in the eastern Canadian Arctic, but the exact breeding origins were difficult to determine due to the lack of differentiation between colonies.