Jon-Ivar Westgaard

A diagnostic tool for efficient analysis of the population structure, hybridization and conservation status of European whitefish (Coregonus lavaretus (L.)) and vendace (C. albula (L.))

Coregonids constitute one of the most diverse fi sh families in the northern freshwater systems and several species are highly endangered mainly due to anthropogenic pressure. Cost effective and powerful polymerase chain reaction (PCR) microsatellite multiplex assays were established for genetic studies of the population structure, hybridization and conservation status of European whitefi sh (Coregonus lavaretus (L.)) and vendace (C. albula (L.)). An assay containing four PCR multiplexes for co-amplifi cation of 9, 5, 3, and 4 loci was developed for C. lavaretus. Cross-species amplifi cation and rearrangement of the same loci resulted in an assay containing three multiplex reactions of 6, 3, and 4 loci for C. albula. Highly signifi cant pair-wise FST estimates were obtained between C. albula from L. Vaggatem (Norway) and L. Palojärvi (Finland) (FST = 0.301, p < 0.001), between C. lavaretus from L. Skrukkebukta (Norway) and L. Stuorajavri (Norway) (FST = 0.161, p < 0.001), and between morphpairs occurring in the two latter lakes (FST = 0.0135-0.043, p < 0.001). The multiplex assays provided a 100% correct assignment success for discriminating C. lavaretus and C. albula and hence provide a powerful diagnostic tool for the future management of these species.

“Real-time” genetic monitoring of a commercial fishery on the doorstep of an MPA reveals unique insights into the interaction between coastal and migratory forms of the Atlantic cod

“Real-time” genetic monitoring of a commercial fishery on the doorstep of an MPA reveals unique insights into the interaction between coastal and migratory forms of the Atlantic cod Torild Johansen*, Jon-Ivar Westgaard, Bjørghild B. Seliussen, Kjell Nedreaas, Geir Dahle, Kevin A. Glover, Roger Kvalsund, and Asgeir Aglen Tromsø Department, Institute of Marine Research Norwegian, PO Box 6404, 9294 Tromsø, Norway Bergen Department, Institute of Marine Research Norwegian, PO Box 1870, 5817 Bergen, Norway Department of Biology, University of Bergen, P.O. Box 7803, N-5020 Bergen, Norway Runde Environmental Centre, Rundavegen 237, 6096 Runde, Norway *Corresponding author: tel: þ47 97959302; e-mail: torild.johansen@imr.no.

Dispersal routes of marine range expansions into the Arctic

As a result of ocean warming, the species composition of the Arctic seas has begun to shift in a boreal direction. One ecosystem prone to fauna shifts is the Northeast Greenland shelf. The dispersal route taken by boreal fauna to this area is, however, not known. This knowledge is essential to predict to what extent boreal biota will colonise Arctic habitats. Using population genetics, 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 pelagic offspring were dispersed via advection across the Fram Strait. Our results indicate that boreal invasions of Arctic habitats can be driven by advection, and that the fauna of the Barents Sea can project into adjacent habitats with the potential to colonise putatively isolated Arctic ecosystems such as Northeast Greenland.As a result of ocean warming, 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 biota will dominate and alter Arctic 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.