Ecology of novel and Native salmonids In Svalbard fjords: harbingers of Changing climate and Ecosystem services in the Arctic (NICE)

Svalbard is at the frontier of climate change. The western fjords of Svalbard are now undergoing Atlantification, in which warmer Atlantic waters are being transported northward. Consequently, western Svalbard fjords are increasingly adopting colonizing species from the Atlantic Ocean. Among the recent arrivals are Atlantic salmon moving father north for feeding. Simultaneously, the invasive pink salmon is spreading throughout the north Atlantic and has been observed in Svalbard, including attempts to enter the rivers used only by native Arctic charr to spawn. The Artic charr is no longer the only salmonid in the waters of Svalbard. This project aims to use integrative ecosystem monitoring tools to investigate fjord ecology of salmonids in Svalbard. The primary tool for this is acoustic telemetry, a technology that uses coded transmitters implanted into individual fish, whose transmissions are saved onboard receivers deployed in Isfjorden. Acoustic tags can also be fitted with sensors such as depth, temperature, and acceleration that reveal details of individual behavior and ecophysiology. This research aims to determine how the native, colonising, and invasive salmonids use the fjord, their thermal experience in the environment, and vulnerability to predation by marine mammals that inhabit the fjord. The research not only has relevance to climate adaptation for northern societies such as the people living in Longyearbyen, but has key management implications given the scale of the establishment of pink salmon in the Atlantic. As the Arctic is continuing to warm, the question of who becomes climate winners is still uncertain. The NICE project is therefore perfectly positioned to contribute novel scientific data to support climate change adaptation in this rapidly changing part of the planet.

Svalbard is at the frontier of climate change. The western fjords of Svalbard are now undergoing Atlantification, in which warmer Atlantic waters are being transported northward into fjords such as Isfjorden. Consequently, Isfjorden and other western Svalbard fjords are increasingly welcoming colonizing species from the Atlantic Ocean. Among the recent arrivals in Svalbard are Atlantic salmon, a species that is now Red Listed in Norway in part due to a lack of knowledge about salmon in their marine phase. Simultaneously, the invasive pink salmon is spreading throughout the north Atlantic and has been observed in Svalbard, including attempts to enter the rivers used only by native Arctic charr to spawn! Evidently, the Arctic is changing at a pace that is rapidly outracing science's capacity to provide effective and evidence-based advice. Our team recently completed a workshop in Longyearbyen focused on the value of acoustic telemetry as a monitoring and research platform in Svalbard and we have now deployed multiple acoustic receivers around Isfjorden for tracking Arctic charr in a pilot project. This has perfectly prepared and situated our team to start the 4-year Salmonids in Svalbard project. Salmonids in Svalbard will gather data during the lost years- when Atlantic and invasive pink salmon leave their home rivers and swim in the vast ocean. Our data will test hypotheses about the movement patterns of the native, colonizing, and invasive salmonid on this remote archipelago, investigate the thermal niche of the species in the frigid Arctic waters, and use acoustic sensor tags to identify predation by marine mammals such as beluga whale that have been observed by locals consuming Atlantic salmon. Isfjorden is unique in that it has all the tools and amenities needed for a comprehensive research program on salmonids at the northern limit of their distribution in a changing world where so little is known about this phase for these at risk species.