Dispersal routes of climate-induced marine range expansions into the Arctic

As a result of climate change, the species composition of Arctic habitats has begun to shift in an Atlantic direction. One ecosystem exposed to such a change is the Arctic Northeast Greenland shelf. However, the dispersal route taken by boreal fauna to this area is unknown. This knowledge is essential to predict to what extent boreal fauna will dominate Arctic habitats, and alter ecosystems. We show that Atlantic cod ( Gadus morhua ), beaked redfish ( Sebastes mentella ), and deep-sea shrimp ( Pandalus borealis ) specimens recently found on the Northeast Greenland shelf originate from the Barents Sea, and suggest that a likely dispersal route is via advection across the Fram Strait. Our results indicate that boreal invasions of Arctic habitats can be driven by the dispersal of pelagic offspring, and that the fauna of the Barents Sea can project into adjacent habitats with unknown consequences to the structure and function of putatively isolated Arctic communities.