Assemblage of the abundant biosphere, representing operational taxonomic units (OUTs) that constitute >1% of sequences in a sample.

<p>An OTU represents a cluster of sequences with 97% similarity in the sequence of the 18S rRNA V4 region. The numbering of taxa reflects different sequences that fall into this branch of the phylogenetic tree, but that could not be annotated with higher taxonomic resolution.</p

Diagram illustrating the spatial distribution of chlorophyll <i>a</i> biomass in the observation area in Fram Strait, Nansen Basin and Amundsen Basin.

<p>Data are interpolated based on point measurements and do not reflect measurements in between the sampling sites. A: Spatial distribution of total chlorophyll <i>a</i> biomass including micro-, nano-, and pico-plankton. B: Spatial distribution of pico-eukaryotic chlorophyll <i>a</i> biomass. C: Relative contribution of pico-eukaryotic chlorophyll <i>a</i> biomass to total chlorophyll <i>a</i> biomass.</p

Environmental parameter of the water column at the chlorophyll <i>a</i> maximum of sampling sites^a.

<p>Environmental parameter of the water column at the chlorophyll <i>a</i> maximum of sampling sites<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148512#t001fn001" target="_blank">^a</a>.</p

Temperature-salinity diagram of the CTD stations.

<p>Profiles shallower than 50 m are shown as black lines and profiles deeper than 50 m as gray lines. The biological samples are marked where they were taken in the water column and named according to the labelling in the metaMDS plot from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0148512#pone.0148512.g004" target="_blank">Fig 4</a>. The surface freezing line is shown in blue and the isopycnals in black.</p

Biogeography of pico-eukaryote communities determined by ARISA.

<p>A: Meta MDS plot displaying similarity between pico-eukaryote communities based on the Jaccard Index. B: Allocation of grouping in the MDS-plot to sampling locations. Modified after Rudels et al. (2012), major ocean currents were sketched into the map. Atlantic inflow is sketched in black, while modified Atlantic Water is sketched in orange.</p

Community assemblage based on 454-NGS sequencing of selected samples representing the grouping in the MetaMDS-plot.

<p>Community assemblage based on 454-NGS sequencing of selected samples representing the grouping in the MetaMDS-plot.</p