Digital elevation model (DEM), surveyed stream network (SSN), mask and stream sampling points (SSP)

These data are provided to allow users for reproducibility of an open source tool entitled 'automated Accumulation Threshold computation and RIparian Corridor delineation (ATRIC)'

(Table 1) Summary of sampling points described and main petrographic, morphological and geochemical characteristics

Targeted sampling on the Dolgovskoy Mound (northern Shatsky Ridge) revealed the presence of spectacular laterally extensive and differently shaped authigenic carbonates. The sampling stations were selected based on sidescan sonar and profiler images that show patchy backscatter and irregular and discontinuous reflections in the near subsurface. The interpretation of acoustic data from the top part of the mound supports the seafloor observations and the sampling that revealed the presence of a complex subsurface plumbing system characterized by carbonates and gas. The crusts sampled consist of carbonate cemented layered hemipelagic sedimentary Unit 1 associated with several centimetres thick microbial mats. Three different carbonate morphologies were observed: (a) tabular slabs, (b) subsurface cavernous carbonates consisting of void chambers up to 20 cm**3 in size and (c) chimney and tubular conduits vertically oriented or forming a subhorizontal network in the subsurface. The methanogenic origin of the carbonates is established based on visual observations of fluids seepage structures, 13C depletion of the carbonates (d13C varying between -36.7 per mil and -27.4 per mil), and by thin carbonate layers present within the thick microbial mats. Laboratory experiments with a Hele-Shaw cell were conducted in order to simulate the gas seepage through contrasting grain size media present on the seafloor. Combined petrography, visual observations and sandbox simulations allowed a characterization of the dynamics and the structures of the plumbing system in the near subsurface. Based on sample observations and the experiments, three observed morphologies of authigenic carbonates are interpreted, respectively, as (a) Darcian porous flow through the finely laminated clayey/coccolith-rich layers, (b) gas accumulation chambers at sites where significant fluid escape was impeded by thicker clayey layers forming the laminated Unit1 and (c) focussed vertical fluid venting and subhorizontal migration of overpressured fluids released from (b). The Hele-Shaw cell experiments represent a promising tool for investigating shallow fluid flow pathways in marine systems.

Sampling information, length measurements, DNA alignments, models and phylogenetics trees for Oithona similis s.l.

Traditionally, many small-sized copepod species are considered to be widespread, bipolar or cosmopolitan. However, these large-scale distribution patterns need to be re-examined in view of increasing evidence of cryptic and pseudo-cryptic speciation in pelagic copepods. Here, we present a phylogeographic study of Oithona similis s.l. populations from the Arctic Ocean, the Southern Ocean and its northern boundaries, the North Atlantic and the Mediterrranean Sea. O. similis s.l. is considered as one of the most abundant species in temperate to polar oceans and acts as an important link in the trophic network between the microbial loop and higher trophic levels such as fish larvae. Two gene fragments were analysed: the mitochondrial cytochrome oxidase c subunit I (COI), and the nuclear ribosomal 28S genetic marker. Seven distinct, geographically delimitated, mitochondrial lineages could be identified, with divergences among the lineages ranging from 8 to 24 %, thus representing most likely cryptic or pseudocryptic species within O. similis s.l. Four lineages were identified within or close to the borders of the Southern Ocean, one lineage in the Arctic Ocean and two lineages in the temperate Northern hemisphere. Surprisingly the Arctic lineage was more closely related to lineages from the Southern hemisphere than to the other lineages from the Northern hemisphere, suggesting that geographic proximity is a rather poor predictor of how closely related the clades are on a genetic level. Molecular clock application revealed that the evolutionary history of O. similis s.l. is possibly closely associated with the reorganization of the ocean circulation in the mid Miocene and may be an example of allopatric speciation in the pelagic zone.