Increasing influence of Atlantic water in the Arctic Ocean has the potential to significantly impact regional water temperature and salinity. Here we use a rDNA barcoding approach to reveal how microbial communities are partitioned into distinct assemblages across a gradient of Atlantic-Polar Water influence in the Norwegian Sea. Data suggest that temperate adapted bacteria may replace cold water taxa under a future scenario of increasing Atlantic influence, but the eukaryote response is more complex. Some abundant eukaryotic cold water taxa could persist, while less abundant eukaryotic taxa may be replaced by warmer adapted temperate species. Furthermore, within lineages, different taxa display evidence of increased relative abundance in reaction to favourable conditions and we observed that rare microbial taxa are sample site rather than region specific. Our findings have significant implications for the vulnerability of polar associated community assemblages, which may change, impacting the ecosystem services they provide, under predicted increases of Atlantic mixing and warming within the Arctic region.
Bibliographical noteFunding Information:
The altimeter products were produced by Ssalto/Duacs and distributed by Aviso with support from Cnes. The OSTIA high resolution sea surface temperature and sea ice data were provided through the Copernicus Marine Environment Monitoring Service (www.marine.copernicus.eu). The map in Fig. 1 was produced using the m_ map toolbox for Matlab76. We’d also like to thank the UK Ocean Acidification programme, the crew and officers of the RSS James Clark Ross during cruise JR271. Contribution to manuscript preparation by FC was supported by Arctic PRIZE research project (NE/P006302/1), part of the Changing Arctic Ocean programme funded by the UKRI Natural Environment Research Council (NERC). The UK Ocean Acidification research program was funded by the Natural Environmental Research Council through grant numbers NE/H017348/1 and NE/ H016996/1. Finally, MCG received a NERC UKRI SPITFIRE studentship.
© 2020, The Author(s).