Boreal marine fauna from the Barents Sea disperse to Arctic Northeast Greenland

Adam J Andrews,Arve Lynghammar,Christophe Pampoulie,Shripathi Bhat,Jørgen S Christiansen,Kim Præbel,Jon-Ivar Westgaard

doi:10.1038/s41598-019-42097-x

Abstract

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) 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.

Highlights

In 2015 and 2017, boreal species, i.e. juvenile Atlantic cod (Gadus morhua), juvenile beaked redfish (Sebastes mentella), and adult deep-sea shrimp (Pandalus borealis), were observed on the Northeast (NE) Greenland shelf for the first time since surveying began in 200213
We found that all cod (n = 10), and 95% of redfish (n = 61 out of 64) caught on either the NE Greenland shelf or in the Fram Strait, were genetically assigned to the Barents Sea North East Arctic Cod (NEAC) population (Fig. 2c), and the Norwegian Shallow (NSH) redfish population (Fig. 2f), respectively
Assignment with STRUCTURE was supported by high membership probabilities (q > 0.8), which suggest that the three species on the NE Greenland shelf all originate from the Barents Sea

Summary

Introduction

In 2015 and 2017, boreal species, i.e. juvenile Atlantic cod (Gadus morhua), juvenile beaked redfish (Sebastes mentella), and adult deep-sea shrimp (Pandalus borealis), were observed on the Northeast (NE) Greenland shelf (latitudes 74–77 °N, Fig. 1) for the first time since surveying began in 200213. This was well outside of their known distribution ranges[4,14,15] (Fig. 2a,d,g). The Norwegian Atlantic Current, along the Norwegian coast, and the West Spitsbergen Current[17,20], along the Barents Sea shelf-break, are already known to advect cod, redfish, and shrimp offspring from the Norwegian coast and the Barents Sea proper to Spitsbergen, east of the Fram Strait[21,22,23]

Methods

Results

Conclusion