Fig. 2
Overview of the sampled stations in the Baltic Sea, the Kattegat and the Skagerrak and general data structure based on 18S and 16S rRNA metabarcoding data. (A) Map of the Baltic Sea with its salinity gradient (redrawn from46) and the 22 sampled stations. Three of the stations (indicated with grey circles in the map) had less than five samples and were not included in the analyses presented in panels B and C. (B) Seasonal variation in relative abundance of prokaryotic (16S) and eukaryotic (18S) microbial plankton on class level at the individual stations. Mean salinity level (PSU) measured and number of samples taken (n) at each station are depicted. (C) NMDS plots of β-diversity measured by Bray-Curtis distance of 16S and 18S sequencing data; of all stations and three individual stations at the extremes and the middle of the salinity gradient. For plots of individual stations, data points are not sized by salinity.
