PorpAdapt · Radiation and adaptation of harbor porpoises within the North Atlantic

Marine mammals face few physical barriers to dispersal, yet evidence of isolation, genetic differentiation and local adaptation have been reported for many species; comprising what has been referred to as the marine-speciation paradox. The harbour porpoise (Phocoena phocoena) is a champion of dispersal and population establishment, occurring across the northern hemisphere from subarctic to temperate regions. Despite its ability to disperse across the marine environment, evidence for multiple distinct genetic populations and subspecies have been suggested, indicating barriers to gene flow are present and populations have adapted locally to environmental conditions. Small, genetically isolated populations, such as those in the Belt and Black Seas are at risk of population collapse, with climate change as an impending threat and reported bycatch levels from commercial fisheries greater than five times sustainable estimates. Comprehensively assessing the connectivity of North Atlantic populations, assessing genomic erosion, and understanding the extent of local adaptations is essential to implement conservation strategies. I propose leveraging 311 genomes sampled across the entire North Atlantic to compile the most comprehensive dataset of cetacean to date. Drawing on the disciplines of marine biology, genomics, bioinformatics and conservation ecology, I plan to investigate the radiation of harbour porpoise lineages, assess their genomic fitness and document their adaptations to local environments. In a broader context, the results will aid in understanding how marine species form unique lineages and will provide value recommendations to nature managers on the status of harbour porpoise populations. The combination of my experience in speciation genomics and the expertise of my host in conservation and adaptation genomics will ensure the successful implementation of this project and prepare me for a career as a leading researcher in marine mammal science.