This dataset includes in situ observations of CTD casts collected during the PRE-SWOT experiment.

The East Sea Real-time Ocean Buoy (ESROB) is a surface mooring that has been in operation off the mid-east coast of Korea since 1999. The ESROB is 9 km off the coast (37° 32.24’N; 129° 12.92’E) in a water depth of 130 m, and provides meteorological and oceanographic (physical and biogeochemical) data every 10 min from Conductivity-Temperature-Depth (CTD) and acoustic Doppler current profiler (ADCP) instruments. The data provided here were collected between 2016 and 2020 and follow the data collected by previous publications. The data were quality controlled and assured using typical data processing methods, and have been used to address temporal variations in currents and water properties, as well as wind-and tide-induced internal waves. The uploaded data files contain variables in a NetCDF format that were obtained during each deployment. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

RESOLAG is a sensor network located in French Polynesia, in the middle of the South Pacific Ocean. The program started in 2018 to acquire data on seawater parameter inside lagoon impacted by pearl oyster farming activity. It is a long-term monitoring of seawater temperature, disolve oxygen, turbidity, fluorescence and salinity. One of the network’s major goal is to better understand the link between black-pearl oysters and their environment, in order to improve management of the farming activity. RESOLAG was created by the Department for Marine Ressources Management of French Polynesia. It is a public organisation run by the gouvernment of French Polynesia. Therefore all data from the network are publicly available to download (under CC-BY licence). Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

The CARBO-ACID research cruise (EUROFLEETS+ SEA02_10) was carried out on the RV Ramón Margalef between August 2nd and August 11st, with departing from Vigo – Spain and ending in Lisbon – Portugal. The main objective of this cruise was to collect data and samples to study the potential effects of ocean acidification on carbonate marine organisms (coccolithophores, pteropods, planktonic and benthic foraminifera, and corals) along the Iberian margin. With this objective, oceanographic data and water samples, plankton, cold-water corals and sediment samples were collected during an upwelling season, along two transects coinciding with the two persistent upwelling filaments off the Iberia Margin: the Cape Finisterra and the Cape Roca. In this dataset is guiven all the acquired data recollected onboad.  During the CARBO-ACID cruise we did a total of 7 stations, 4 stations along the Cape Finisterra transect (from W to E: CA3, CA2, CA7, CA8) and 3 stations at the Cape Roca (from W to E: CA6, CA5, CA4) transect (Fig). At each station we usually started with a multibeam survey, a CTD and Rosette cast. These initial operations allowed to identify the different water masses present in this area, characterize their physical properties and to recover seawater samples at specific depth levels. The seawater samples were onboard subsampled, preserved in cold conditions or with chemicals and/ or filtered for several further analysis in the shore-based laboratories: DNA, chlorophyll, fitoplankton, coccolithophores, pH, alkalinity, stable isotopic composition, trace elements concentration and Suspend Particulate Matter. Subsequently to these operations, at each station, two vertical tows with a plankton multinet (with 5 nets) were done on the top 700 m of the water column to sample the planktonic communities of the different water depths. After this, sediment samples were recovered with a box-corer to study the past oceanographic conditions, between the pre-industrial Era and the Present, with multi-proxies used in paleoceanography and sedimentology. A total of 10 box-cores were recollected and each of them was onboard sub-sampled for eDNA, enzymes and benthic foraminifera. Fifteen shipek grab samples were recollected at the Fontanelas seamount (Estremadura Spur), station CA6, to characterize the sedimentary cover and to evaluate the presence of deep cold-water corals. Preliminary results show that the stations CA7, CA8 and CA4, located close to the coast, as expected, are the most influenced by the coastal upwelling, exhibiting colder surface water, higher values of fluorescence, and more zooplankton content reflecting higher phyto-zooplankton concentrations, as typical of the upwelling waters. At station CA4 temperature was higher and fluorescence showed lower values, indicative of less phytoplankton, and interpreted as indicating a different upwelling source water from that upwelled further north. Based on the CTD data, the Cape Roca transect is more influenced by the subtropical East North Atlantic Central Water (ENACWst), while the Cape Finisterra transect is more under the influence of the subpolar branch (ENACWsp). Seafloor sediment samples showed significant differences between the stations. Along the northern transect (Cape Finisterra) the seafloor sediments show an increase in grain size from the offshore to the coast. The offshore stations CA3 and CA2 revealed finer grained sediments, CA8 were composed of coarser sand and the station CA7, the shallowest station 77 m, presented the sediment composed mainly of shell fragments and coarse grain sand. Along the southern transect (Cape Roca), the offshore station CA6 (Fontanelas seamount) has coarser sandy sediments with rock clasts and cold-water coral fragments, and the stations CA5 and CA4 with fine sand to muddy sediments. The detailed CA6 bathymetry allowed to verify the existence of small plateaus on the slope of the Fontanelas seamount, where the fossil cold-water corals fragments were found, suggesting that this area is a very interesting system deserving further study with a ROV, and to characterize the corals fields and verify if there are live corals. These recollected data and samples will allow not only to reconstruct the pH variability under different environmental conditions, but also to estimate the biogeochemical changes along the coastal ocean waters as the anthropogenic influence increases. These results will contribute to better understand and model the effects on the biota under the future expected oceans pH changes. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

Hydrographic conditions along a northeastern section off the eastern coast of Qatar Peninsula, Arabian Gulf were measured seasonally for the first time. Six sampling stations, along a 105-km section perpendicular to the major axis of the Gulf, were visited five times within one year (October 2012, January 2013, April 2013, June 2013, and August 2013) to investigate seasonal and spatial variations in hydrographic conditions of Qatar’s exclusive economic zone. Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.

An intensive study at a mussel farm at Tångesund 2016-2017. Here, the connection between the stratification of the water mass, currents, the presence of harmful algae and the presence of algal toxins in mussels will be investigated. A coastal buoy was placed next to the mussel farm with sensors for temperature, salt and oxygen at five different depths. At the surface there was also be a sensor for chlorophyll and turbidity.

Data were collected in the southern Western Black Sea (Bulgarian and Romanian territorial waters) for the Eurofleets+ PHYCOB cruise. This submission contains CTD and nutrient data. The main scientific objectives of the research cruise are: 1) To assess the presence of toxic microalgae in the plankton assemblage of the Western Black Sea. 2) To quantitatively determine the spatial distribution of toxic phytoplankton species and their corresponding toxins in the plankton. 3) To quantitatively describe the spatial distribution of toxic phytoplankton resting stages in surface sediments and determine hotspots of recruitment and bloom initiation. 4) To define correlations among hydrographic and/or meteorological conditions and occurrence of HAB species. 5) To characterize the plankton communities accompanying HAB species together with toxin analysis of size fractionated samples. 6) To identify heterotrophic dinoflagellates, ciliates, or other small zooplankton as possible toxin vectors. 7) To isolate toxic Black Sea microalgal species and establish monoclonal cultures for characterization of Black Sea strains. 8) To perform an interseasonal comparison of toxigenic plankton species by combining the data sets collected during the R/V Akademik cruise that was performed in May/June 2019 with our data from summer. 9) To compare the data set from the Western Black Sea to the Southern (North-) Western North Sea, Baltic Sea and West Greenland obtained during earlier expeditions for site comparisons.

Data collected during the BENCHMARK cruise. The cruise was carried out between August 1-10, 2021 on Denmark Strait, in Icelandic and Greenlandic waters. The objectives of the cruise were to characterise the composition and distribution of epibenthic fauna in the Denmark Strait, with a particular focus on taxa considered indicators of Vulnerable Marine Ecosystem, and to survey water mass properties and flow structure in the area.

The RV Arni Fredriksson collected simultaneous information on hydrology, prey and Brunnichs/common guillemot from 18 to 25/06/2022 in north-west Iceland. 5 transects of 60km length were succesfully completed twice in shelf-waters. A 6th transect of ~ 40km length was performed once in Arnarfjordur. During transects, 2 observers recorded the 2D distribution of all seabirds using European Seabird At-Sea (ESAS) methodology. At the same time, a scientific echosounder (Simrad EK80) operating at 5 frequencies (18, 38, 70, 120, 200 Khz) recorded the 3D distribution of fish. 22 trawls (plankton, midwater and demersal) were performed in response to schools and layers detected in the scientific echosounder, offering insights into their species composition and length-frequencies. 107 CTDs were performed at intervals along transects to measure the 3D variation in temperature, salinity, flourescene and turbidity.

Physical data associated with the ABRACO2 cruise. The ABRACOS2 cruise's main objective was to draw up a 3D characterisation of the abiotic and biotic compartments and their interactions. The cruise had 3 specific objectives: 1) Characterisation of water masses and their dynamics. Data collected (ADCP, CTD, rosette, etc.) will be used to study the physical connections between (i) ocean islands and coastal ecosystems and (ii) tropical/subtropical coastal regions to the South and equatorial coastal regions to the North. In-situ measurements will also make it possible to validate the regional high-resolution hydrodynamic models. 2) Ecosystem acoustics. Collecting multifrequency acoustic data in order to create the first 3D characterisation of island and coastal ecosystems in the Northeast Region of Brazil. Acoustic observations will be combined with sampling with pelagic trawl (Legs 1 and 2), bottom trawl (Leg 1), and with sampling of zooplankton and video images. 3) Biodiversity and food web structure. In-situ sampling will provide information about the distribution, biodiversity, trophic ecology (use of stable isotopes) and the contamination (methylmercury) of organisms. The related projects are ABRAÇOS and 'Planning in a liquid world: Marine spatial planning and network dynamics' (PADDLE), (H2020 RISE), (PI: M. Bonnin, 2017-2020). Important Note: This submission has been initially submitted to SEA scieNtific Open data Edition (SEANOE) publication service and received the recorded DOI. The metadata elements have been further processed (refined) in EMODnet Ingestion Service in order to conform with the Data Submission Service specifications.