List of size fractionated eukaryotic plankton community samples and associated metadata (Database W1)

The present data set provides an Excel file in a zip archive. The file lists 334 samples of size fractionated eukaryotic plankton community with a suite of associated metadata (Database W1). Note that if most samples represented the piconano- (0.8-5 µm, 73 samples), nano- (5-20 µm, 74 samples), micro- (20-180 µm, 70 samples), and meso- (180-2000 µm, 76 samples) planktonic size fractions, some represented different organismal size-fractions: 0.2-3 µm (1 sample), 0.8-20 µm (6 samples), 0.8 µm - infinity (33 samples), and 3-20 µm (1 sample). The table contains the following fields: a unique sample sequence identifier; the sampling station identifier; the Tara Oceans sample identifier (TARA_xxxxxxxxxx); an INDSC accession number allowing to retrieve raw sequence data for the major nucleotide databases (short read archives at EBI, NCBI or DDBJ); the depth of sampling (Subsurface - SUR or Deep Chlorophyll Maximum - DCM); the targeted size range; the sequences template (either DNA or WGA/DNA if DNA extracted from the filters was Whole Genome Amplified); the latitude of the sampling event (decimal degrees); the longitude of the sampling event (decimal degrees); the time and date of the sampling event; the device used to collect the sample; the logsheet event corresponding to the sampling event ; the volume of water sampled (liters). Then follows information on the cleaning bioinformatics pipeline shown on Figure W2 of the supplementary litterature publication: the number of merged pairs present in the raw sequence file; the number of those sequences matching both primers; the number of sequences after quality-check filtering; the number of sequences after chimera removal; and finally the number of sequences after selecting only barcodes present in at least three copies in total and in at least two samples. Finally, are given for each sequence sample: the number of distinct sequences (metabarcodes); the number of OTUs; the average number of barcode per OTU; the Shannon diversity index based on barcodes for each sample (URL of W4 dataset in PANGAEA); and the Shannon diversity index based on each OTU (URL of W5 dataset in PANGAEA).

Ice furrow mapping in the Laptev Sea

During the "Polarstern"-expeditions ARK-IX/4 (1993) and ARK-XI/1 (1995), organised by the Alfred Wegener Institute (AWI), acoustic subbottom profiles (Parasound) have been collected in the Laptev Sea Shelf, Siberia. These data have been interpreted as an indicator of ice scours frequency and off-shore permafrost patterns. An additional acoustic profile data-base was available by the results of the expedition of the Federal Institute for Geosciences and Natural Resources (BGR) of the year 1994. The area of the expedition was located closer to the shelf, therefore supports a better understanding of ice scours frequency in shallower marine environments. The data-file consists of a 2930 km Parasound-traverse and has been subdivided into 586 working profiles. They are characterised by their location, number of ice scours, interpreted patterns of reflection and their extension and morphology. The data have been evaluated statistically and graphically and were presented in a map. Different patterns of sea floor reflection were established by different environments, outer influences (e.g. size of the icebergs, direction of the drift of icebergs) and the climatic history of the region. In the north-westerly region of the Laptev Sea at the continental slope of Severnaya Zemlya the sea floor in shallower depths has been ploughed intensely by recent icebergs. In some regions (40-60m), as an effect of intensely ploughing, the sea floor is hardly defined in acoustic profiles come along with relocation of marine deposits. Glacial diamiet deposits prevented the development of deep scours. Up to 355m deeper scours result from lower sea levels. The marginal north-easterly region of the Laptev Sea is characterised exclusively by this type of scour. Morphology and depth of these scours can be compared with those of the westerly Vilkitsky-Street so that similar conditions of development may be expected. Both, the north-easterly Laptev Sea and the Vilkitsky-Street, are not dominated by patterns ofrecent icebergs. In contrary the shelf-regions north-easterly ofthe Taimyr peninsula and north-westerly of the New Siberian Islands have been modified evidently by recent icebergs, which drifted with prevalent currents anticlockwise along the shelf edge of the Laptev Sea and cause the deepest scours of the whole region. The off-shore permafrost at the inner shelf regions has an important influence on the scours intensity. The permafrost layer can be recognised by the maximum depth of ice scours. It is represented by a Parasound reflector that can be made up for distances. The age of the ice scours cannot be determined absolutely by Parasound data but a relative order can be estimated whenever two scours are situated close to each other. When the Parasound-traverse ofthe expedition ARK-IX/4 (1993) (77°24'N 133°30'E-77°30'N 133°40'E) was repeated partially in expedition ARK-XI/l (1995) the ice scours of 1993 remained unchanged and uneroded and no new ice scours had been detected. It can be concluded that scours persist for a long time in the Laptev Sea, though after all with an average of 3 ice scours per kilometer there are not many at all in the Laptev Sea.