Deep Sea Research Part I: Oceanographic Research Papers

These files contain the density, density anomaly and velocities (computed using geostrophic thermal wind) of composite eddies, which represent the typical 3D shape of eddies in the northeastern Arabian Sea. Data are interpolated on a (x,y,z) grid. To dimensionalize the horizontal dimensions, multiply by the radius of the eddy wanted (e.g 100 km).

Carbon, nitrogen, and sulfur isotopic data for organisms from Manus Basin hydrothermal vents.

Samples for DOC, CDOM and FDOM analysis were collected in open sea waters of the Med Sea during 3 oceanographic cruises carried out in March/April 2008, August 2010 and November 2011 on board the R/V Urania of the Italian National Research Council (CNR). DOC measurements were carried out with a Shimadzu TOC-VCSN, by high-temperature catalytic oxidation. Samples were acidified with HCl 2N and sparged for 3 min with CO2-free pure air in order to remove inorganic carbon. From 3 to 5 replicate injections were performed until the analytical precision was lower than 1% (±1 μM). A 5-point calibration curve was done by injecting standard solutions of potassium hydrogen phthalate between 20 and 130 μM. At the beginning and at the end of each analytical day, the system blank was measured using Milli-Q water and the functioning of the instrument was checked by comparison of data with DOC Consensus Reference Material (CRM) (Hansell, 2005) (batch#7-2007, batch#10-2010/Lot#5-10, batch#11-2011/Lot#03-11, Consensus values: 41 - 44 µM, measured concentration: 41.9 ± 1.3 µM, standard error = 0.23 µM, n = 39). For further analytical details see Santinelli et al. (2010). CDOM absorbance was measured throughout the UV and visible spectral domains (230-700 nm) with a resolution of 0.5 nm, by using a JASCO Spectrophotometer V-550 and a 10 cm quartz cuvette. Fluorescence Excitation Emission Matrixes (EEMs) were recorded by using the Fluoromax4 spectrofluorometer (model FP770 Horiba) with a 1 x 1 cm quartz cuvette in the range 250-450 nm for the excitation and 300-600 nm for the emission. The EEMs were corrected for instrumental bias and subtracted by the EEM of Milli-Q water measured in the same conditions (blank). The Rayleigh and Raman scatter peaks were removed by using the monotone cubic interpolation (shape-preserving) (Carlson and Fritsch, 1989), since water subtraction did not completely remove their signals (Gonnelli et al., 2016; Margolin et al., 2018). EEMs were normalized to the water Raman signal, dividing the fluorescence by the integrated Raman band of Milli-Q water (ex=350 nm, em=371-428 nm), measured the same day of the analysis (Lawaetz and Stedmon, 2009). The fluorescence intensity is therefore reported as equivalent water Raman Units (R.U.). This standardized method was chosen because it is rapid, simple and suitable for routine measurements. No significant variation was observed in the integral of the Raman peak from repeated measurements during the period of the analysis (< 2%). In order to check the repeatability of our measurements the same sample was analyzed 5 times during a period of 3 months, the results showed that the variation was less than 2 % for all the components.

Microsatellite alleles in Genepop format. DNA sequences in fasta format with correspondent geographical coordinates.

This file contains the raw data and data analyses scripts to: Hydrography and food distribution during a tidal cycle above a cold-water coral mound Evert de Froe, Sandra R. Maier, Henriette G. Horn, George A. Wolff, Sabena Blackbird, Christian Mohn, Mads Schultz, Anna-Selma van der Kaaden, Chiu H. Cheng, Evi Wubben, Britt van Haastregt, Eva Friis Moller, Marc Lavaleye, Karline Soetaert, Gert-Jan Reichart, Dick van Oevelen. Deep Sea Research Part I: Oceanographic Research Papers, 2022, ISSN 0967-0637, https://doi.org/10.1016/j.dsr.2022.103854. Abstract: Cold-water corals (CWCs) are important ecosystem engineers in the deep sea that provide habitat for numerous species and can form large coral mounds. These mounds influence surrounding currents and induce distinct hydrodynamic features, such as internal waves and episodic downwelling events that accelerate transport of organic matter towards the mounds, supplying the corals with food. To date, research on organic matter distribution at coral mounds has focussed either on seasonal timescales or has provided single point snapshots. Data on food distribution at the timescale of a diurnal tidal cycle is currently limited. Here, we integrate physical, biogeochemical, and biological data throughout the water column and along a transect on the south-eastern slope of Rockall Bank, Northeast Atlantic Ocean. This transect consisted of 24-hour sampling stations at four locations: Bank, Upper slope, Lower slope, and the Oreo coral mound. We investigated how the organic matter distribution in the water column along the transect is affected by tidal activity. Repeated CTD casts indicated that the water column above Oreo mound was more dynamic than above other stations in multiple ways. First, the bottom water showed high variability in physical parameters and nutrient concentrations, possibly due to the interaction of the tide with the mound topography. Second, in the surface water a diurnal tidal wave replenished nutrients in the photic zone, supporting new primary production. Third, above the coral mound an internal wave (200 m amplitude) was recorded at 400 m depth after the turning of the barotropic tide. After this wave passed, high quality organic matter was recorded in bottom waters on the mound coinciding with shallow water physical characteristics such as high oxygen concentration and high temperature. Trophic markers in the benthic community suggest feeding on a variety of food sources, including phytodetritus and zooplankton. We suggest that there are three transport mechanisms that supply food to the CWC ecosystem. First, small phytodetritus particles are transported downwards to the seafloor by advection from internal waves, supplying high quality organic matter to the CWC reef community. Second, the shoaling of deeper nutrient-rich water into the surface water layer above the coral mound could stimulate diatom growth, which form fast-sinking aggregates. Third, evidence from lipid analysis indicates that zooplankton faecal pellets also enhance supply of organic matter to the reef communities. This study is the first to report organic matter quality and composition over a tidal cycle at a coral mound and provides evidence that fresh high-quality organic matter is transported towards a coral reef during a tidal cycle.

The data consist of ~600 U-Th ages of scleractianian cold-water corals dated by laser ablation and isotope dilution methods covering the last 150,000 years. The corals are from three locations: Reykjanes Ridge (57°N to 61°N, 28°W to 33°W); Tropic Seamount (23°55'N, 20°45'W); and the East Equatorial Atlantic from Carter (9°N, 21°W) and Knipovich seamounts (5°N, 27°W). The samples were collected with ROV and dredges during the cruises: CE0806 in 2008 (Reykjanes Ridge); JC094 in 2013 (Equatorial Atlantic); and JC142 in 2016 (Tropic Seamount). Additionally, a compilation of ~750 U-Th and 14C ages of scleractianian cold-water corals from the Northeast Atlantic Ocean is presented. The complete dataset is used to investigate the temporal and spatial coral distribution at Northeast Atlantic Ocean and the relation with past climatic events.

These supplemental animations depict particle backtrack pathways from the sampled spring distributions of six euphausiid species in the southern California Current System to the prior winter origins of water masses that effect each species. The goal of our study was to explore the sole influence of horizontal advection in describing interannual variability in each euphausiid species. The particle backtracks explicitly model the water masses that affect each species in spring; mismatches between variability in those water masses and variability in biomass of a species suggest the species underwent additional in situ biological changes. We used modeled flow field outputs from the California State Estimate, a regionally optimized downscale of the MITgcm, to force a particle backtracking model. The model encompasses 2008-2017. The euphausiid biomass samples come from the CalCOFI program. We first objectively mapped the biomass values from the individual stations for a single spring onto a smooth, interpolated surface to depict the distribution across the entire region. From that surface, we identified the threshold contours encompassing the regions of >80% biomass and 50-80% biomass. We then seeded particles within those contours to represent that spring distribution, and then backtracked the particles for four months to the prior December.

Connectivity is a fundamental process driving the persistence of marine populations and their adaptation potential in response to environmental change. In this study, we analysed the population genetics of two morphologically highly similar deep-sea sponge clades (Phakellia hirondellei and the 'Topsentia-and-Petromica (TaP)' clade) at three locations in the Cantabrian Sea. Sponge taxonomy was assessed by spicule analyses, as well as by 18S sequencing and COI sequencing. The corresponding host microbiome was analysed by 16S rRNA gene sequencing. In addition we set up an oceanographic modelling framework, for which we used seawater flow cytometry data (derived from bottom depths of CTD casts) as ground-truthing data.

Macrofauna data was collected using a box corer (0.25m² sampling area). The sampled sediment from each box corer was divided into eight subsamples (pseudoreplicates). The uppermost 12 cm of these subsamples were analyzed. Each subsample was processed through a 500-µm mesh size sieve. After sieving, residuals were fixed with 100% ethanol and stored at room temperature. Macrofaunal organisms were identified to the lowest possible taxonomical level. Whenever identification to species level was not possible, the sample was identified to the next identifiable taxonomical category and assigned a putative species name (e.g., 'Hesionidae genus sp. 1', 'Hesionidae genus sp. 2'). Posterior fragments, exuviae, xenobionts, meiofauna taxa (Nematoda, Ostracoda, Harpacticoida) and empty tubes were excluded from the analysis. Biomass (blotted wet weight, ww) was determined by weighing each specimen. Shelled organisms, such as mollusks, were weight in their shells.

Understanding present-day sediment provenance and transport processes is crucial for studies about the dynamics of ocean circulation, as well as for paleoclimate reconstructions in the Drake Passage (DP), a key area for Earth's global oceanic circulation and climate during past and future. Based on a comprehensive set of surface sediment samples, we used spatial variations in grain-size distribution, bulk sediment mineralogy, silt and clay mineralogy across the entire DP region to elucidate the terrigenous sources and transport mechanisms. The statistical evaluation of these data identifies southern Patagonia (carbonate, illite, chlorite, feldspar and quartz) and the Antarctic Peninsula (chlorite, smectite, and amphibole) as the main sources for terrigenous sediments in the DP region. Different current systems are transporting the sediment material. Here, we provide a new, robust flow speed calibration for silt grain-sizes to enable the reconstruction of Antarctic Circumpolar Current (ACC) dynamics in the DP sector of the Southern Ocean. We correlated the sortable silt mean grain-size records of surface sediments with adjacent long-term current meter data. A clear bottom current speed pattern shows the variability of the ACC in the DP responding to the dynamics of ocean fronts, in agreement with modern observation.