MARLEY (Monitoring deep-seA coRaL EcosYstems) is a deep seafloor observing system dedicated to the monitoring of cold-water coral habitats. The system is deployed in the Lampaul canyon off Brittany, France since August 2021 and maintained each year during the ChEReef-Obs cruises. The study site is a coral garden dominated by Madrepora oculata, located on a sedimented platform at 780 m depth. MARLEY is equipped with a CTD SBE 37-SIP, an oxygen optode Aanderaa (4330 or 4831), an ADCP Teledyne RDI Workhorse 300kHz, a turbidity sensor Wetlabs ECO NTU (sensitivity: 0-1000 NTU), a sediment trap Technicap PPS 4/3 – 24 bottles and a camera module. The camera module, which can be moved from up to 30 m from the main station, is equipped with a camera AXIS Q1786, two flash lights and a fluorometer & scattering meter SEA-BIRD ECO FLNTU. All sensors are controlled and synchronised by the Communication and Storage Front-end - 2nd generation (COSTOF2), which is also managing data storage. Optical sensors are protected from fouling by electrochlorination (20 seconds, each 6 hours). The oxygen optode is calibrated each year prior to deployment. These datasets provide raw data from the oxygen optode Aandera 4831, the CTD Seabird SBE37, the Wetlabs ECO NTU and the SEAR-BIRD ECO FLNTU covering the period 28/08/2021 to 19/01/2022, with a frequency of 15 minutes. Data from Wetlabs ECO NTU include raw counts and Nephelometric Turbidity Unit (NTU) derived from manufacturer’s calibration with Scale Factor = 0.0611 and Dark Counts = 50. Data form SEABIRD ECO FLNTU include raw counts at 695 nm (Chlorophyll) and 700 nm (Turbidity). Chlorophyll concentration (µg/l) is derived from manufacturer’s calibration with Scale Factor = 0.0180 and Dark Counts = 48. Nephelometric Turbidity Unit (NTU) is derived from manufacturer’s calibration with Scale Factor = 0.0481 and Dark Counts = 50. 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 measurements of SPM, particulate TN, TC, Fe, Mn, Al and chlorophyll a, as well as light absorption at 750 nm and 380 nm were done within Estonia-Latvia transboundary project "Towards joint management of the transboundary Gauja/Koiva river basin district" for harmonization of water quality classification system for transboundary water bodies in the Gauja/Koiva river basin district and adjacent areas (in Estonia) in the Gulf of Riga." Measurements were done once in August 2012 along with underwater video observation, water transparency and CTD measurements in coastal waters in shallow part (2 - 12m) of the East coast of the Gulf of Riga. Data were used for Final report on assessment of the quality status of the transboundary water bodies (coastal, lakes, rivers) in Gauja/Koiva river basin district (2013. Kalvane I. and Veidemane K. (eds.))

The SCENES monitoring station is part of the SNO COAST-HF national network (ILICO-RI), and the regional PHRESQUES observation network. The station includes i) a surface buoy equipped with a CTD and an optical turbidity and fluorescence sensor measuring approximately 1.5m below surface and ii) a benthic station equipped with an optical turbidity sensor and an up-looking ADCP (before Oct. 2017 – optical sensor ~ 1.4m above the bed, after Oct. 2017 : 0.5m above the bed). Due to technical problems, the time series, for all sensors, is discontinuous. Optical turbidity measurements can be transformed in suspended particulate matter concentration (SPMC, in g/l) using a calibration relationship built from the PHRESQUES field campaigns (SPMC=0.00156*NTU+0.001). The acoustic backscatter signal was processed to retrieve SPMC values using optical turbidity sensors and observations from the PHRESQUES Field campaigns.  This dataset allows to investigate hydrodynamics and sediment dynamics from the tidal scale to the seasonal and interannual scale from water level, current velocity, salinity, temperature and SPM concentration measurements. Please refer to associated publications. 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.

This dataset contains the CTD data collected during the GOMBESSA 6 cruise, from 1 to 12 July 2021, in Corsica, western Mediterranean, jointly by the (MARBEC MARine Biodiversity, Exploitation and Conservation)-[http://www.umr-marbec.fr/en/?lang=en] (France) teams. The full-depth CTD profiles were performed using an autonomous SeaBird SBE 19plus V2 SeaCAT Profiler CTD, from the Pionnier vessel belonging to (Seaowl)-[https://web.facebook.com/page.andromede/?_rdc=1&_rdr] France and chartered by the French Navy. Nine stations, from the depth of 115 m to the surface, were sampled off the Corsica coasts (western Mediterranean basin) between latitude 43.11-43.74 °N and longitude 9.49-9.52 °E. The acquisition rate was 4 Hz. The accuracy, specified by the manufacturer, were ± 0.005 °C for temperature and ± 0.0005 S/m for conductivity. The dataset is provided in different formats (CSV, NetCDF, Ocean Data View collection), which contains, for each station the following parameters: Depth [salt_water,m] Temperature [ITS-90,deg-C] pH Salinity, Practical [PSU] Conductivity [S/m] Density [kg/m^3] Oxygen [mL/L] Oxygen_sat [% saturation] Oxygen_umoll [umol/L] Turbidity [NTU] Fluorescence [mg/m^3] Light [PAR/Irradiance] QC (reference: OceanSITES quality flags http://www.oceansites.org/docs/oceansites_user_manual_version1.2.doc) Julian Days and UTC time (yyyy-mm-ddThh:mm:ss.sss) The ZIP archives contain 1/ a map of stations 2/ the list of the ID stations, geographic coordinates and general metadata 3/ all raw data acquired, for all parameters, in CNV format, 4/ the downcasts and upcasts in CSV format, 5/ the upcasts only in ODV, 6/ NetCDF and 7/ TXT formats, and 8/ two vertical profile graphs including all stations (sea water temperature and oxygen). All data acquired are publicly accessible without any restriction (under CC-BY licence). The extracted data are accessible from this GOMBESSA 6 landing page with a downloadable ZIP file. 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.

During the late spring and summer of 2020, the SLU Aqua Sailor drone sails between the great Swedish islands of Öland and Gotland and collects data on the amount of fish and zooplankton. The drone survey partly takes place at the same time as the fisheries survey Sprat Acoustic Survey (Spras). Spras collects information on herring and sprat in the Baltic Sea, and is carried out with the research vessel R/V Svea. By matching data from Spras with data from the sailing drone, the researchers hope to gain better knowledge of how the Baltic Sea ecosystem works. This was repeated in 2022-2023. In 2019, SLU Aqua Sailor was used around the islands Karlsöarna in the Baltic Sea during 42 days between April and July 2019. The same survey took place In 2020 and 2021

Repeat hydrography, as organized through the GO-SHIP network, is fundamental for detecting trends and variability also in the Mediterranean Sea. The Mediterranean component of GO-SHIP is MedSHIP, and TAlPro is the western Mediterranean component. The TAlPro2022 cruise consisted of 26 full depth hydrographic stations crossing the Tyrrhenian Sea from north to south, then the Algero-Provencal Basin from south to north. Here the postcalibrated bottle file data are made availiable. Postcalibration has been done by measuring dissolved oxygen and salinity on water samples collected by the rosette. The dataset contains also all chemical variables, measured in the lab.

Samples collected from an underway Towfish during RV Sanna cruise GLICE (August 2022) and either analysed at sea or returned preserved to GEOMAR for analysis. Sensor data refers to in-line data matching the underway samples.