Viral Characteristics of the Warm Atlantic and Cold Arctic Water Masses in the Nordic Seas

Abstract

Nordic Seas are the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean with complex water masses, experiencing an abrupt climate change. Though the knowledge of the marine virosphere has been expanded rapidly, the diversity of viruses and their relationships with host cells and water masses in the Nordic Seas remains to be fully revealed. Here we establish the Nordic Seas DNA viromes (NSVs) dataset of 55,315 viral contigs including 1,478 unique viral populations from seven stations influenced by both the warm Atlantic and cold Arctic water masses. Caudovirales dominated in the seven NSVs, especially in the warm Atlantic waters. The major giant nucleocytoplasmic large DNA viruses (NCLDVs) contributed a significant proportion of the classified viral contigs in the NSVs (32.2%), especially in the cold Arctic waters (44.9%). The distribution patterns of Caudovirales and NCLDVs were a reflection of the community structure of their hosts in the corresponding water masses and currents. Latitude, pH, and flow speed were found to be key factors influencing the microbial communities and co-influencing the variation of viral communities. Network analysis illustrated the tight coupling between the variation of viral communities and microbial communities in the Nordic Seas. This study suggests a probable linkage between the viromes, host cells and the surface water masses from both the cool Arctic and warm Atlantic Oceans. Importance: This is a systematic study of Nordic Seas Viromes using metagenomic analysis. The viral diversity, community structure, and their relationships with host cells and the complex water masses from both the cool Arctic and warm Atlantic Oceans were illustrated. The NCLDVs and Caudovirales are proposed as the viral characteristics of the cold Arctic and the warm Atlantic waters, respectively. This study provided an important background for the viromes in the subarctic seas connecting the Arctic Ocean and North Atlantic Ocean, and will shed a light on their responses to the abrupt climate change in the future.

Ecological Interaction between Bacteriophages and Bacteria in Sub-Arctic Kongsfjorden Bay, Svalbard, Norway

“…In the present study, Myoviridae , Podoviridae , Siphoviridae , and Herelleviridae were the most common bacteriophages identified, consistent with their common occurrence in oceans [ 55 ]. The presence of Pelagibacter phage HTVC008M and Puniceispirillum phage HMO-2011, including the Pelagibacter phage group, suggests that the SAR11 bacterial group is abundant in the Arctic Ocean [ 56 ]. The co-occurrence of various phages with various bacteria indicates that phages may be capable of infecting multiple host bacterial ecotypes in warm- and cold-water environments [ 57 ].…”

Covariance of Marine Nucleocytoplasmic Large DNA Viruses with Eukaryotic Plankton Communities in the Sub-Arctic Kongsfjorden Ecosystem: A Metagenomic Analysis of Marine Microbial Ecosystems

“…This is likely due to the diversity of Mimiviridae structure and, a subsequent, broad range of hosts and environments compared to the reference sequences of known viral genomes [ 58 ]. In particular, Mimiviridae species are frequently found in low-temperature seawater, such as in the Arctic [ 59 , 60 ], which is likely related to the frequency and types of hosts. Indeed, our results showed that Mimiviridae and Pandoraviridae were significantly and positively correlated with specific EPC taxa, namely, Aureococcus anophagefferens (pOTU#0) increased rapidly in June, as did Megavirus chiliensis (vOTU#69) and Chrysochromulina ericina virus (vOTU#26) also increased.…”

Spatiotemporal Dynamics of Coastal Viral Community Structure and Potential Biogeochemical Roles Affected by an Ulva prolifera Green Tide

“…2 to 4 ; Fig. S2 and S3 ), suggesting that marine viruses in general are still largely uncharacterized ( 30 – 34 ). In general, the spatiotemporal dynamics of abundance, community structure, and diversity of the viral assemblages ( Fig.…”