For the 21 years of the study, an examination of trends in chlorophyll concentration revealed a general decline throughout the Gulf over the production period. These trends, extracted from dynamic linear model, also allowed this decline to be quantified. Expressed as a percentage, a large part of the area below the 50 m bathymetric line showed a decrease of at least 10% over the period, corresponding to a value of at least 0.1 µg.l-1. However, the spatial distribution reveals some more local phenomena. In southern Brittany, from Quimper to Vannes, a particular feature appears, with an upward trend over several kilometres along the coast, followed by a pronounced gradient along the coast. This gradient includes a zone where a continuous monotonic increasing trend is observed, then a zone where the trend becomes not significant and finally, about 15 km from the coast, a new zone where a significant continuous monotonic decreasing trend is observed. The increase in chlorophyll a concentration in the very coastal part is greater than 0.1 µg.l-1 over the period. Another peculiarity concerns the central part, located at the edge of the plateau at Cap Ferrat and Pente Aquitaine, where an increase in chlorophyll a was observed, but the variations remained small, being less than 0.1 µg.l-1. About a hundred kilometres south-west of Saint Nazaire, an area of about 40 by 50 km shows a decrease in chlorophyll a of more than 20%, quantified as more than 0.1 µg.l-1 over the period. 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.))

CTD casts collected in East Arm and Bonne Bay during August 3-4 to measure the density stratification with depth. Cast depths range from 50 to 200 m.    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.

As part of the second mission of the (GOCART)-[https://projects.noc.ac.uk/gocart/] (Gauging Ocean organic Carbon fluxes using Autonomous Robotic Technologies) project, funded by the European Research Council, a Slocum glider (unit-405, Doombar) spent about 4 months surveying the top 1000m of a low oxygen region of the Northern Benguela Upwelling region, off the coast of Namibia. The goal of the mission was to characterize the temporal variability in organic carbon flux and remineralisation depth during the spring bloom in a highly productive but low oxygen region in the Benguela Current, off the Namibian coast. The glider was a Teledyne Webb Research (Slocum)-[https://www.teledynemarine.com/brands/webb-research/slocum-glider] G2, equipped with: Seabird Glider Payload CTD (pumped), measuring temperature, conductivity and pressure Sea-Bird WETLabs ECO Puck Triplet BB2FL-SLC scattering fluorescence sensor, measuring chlorophyll fluorescence and optical backscattering at 700 and 532nm Aanderaa 4831 oxygen optode, measuring dissolved oxygen concentration. The glider was deployed at 11.225°E, 19.331°S on 14th February 2018 from the RV Mirabilis, the vessel of the Namibian Ministry of Fisheries, during the second leg of the 2018 Hake Survey off the northern Namibian shelf and recovered on June 19th, 2018 during the (DY090 cruise)-[https://www.bodc.ac.uk/resources/inventories/cruise_inventory/report/16386/] on board RSS Discovery, during the COMICS cruise (Controls over Oceanic Mesopelagic Interior Carbon Storage), funded by the Natural Environmental Research Council. The latter cruise was in the vicinity of the glider from 1st-19th June, 2018. To validate/calibrate the glider sensors, we conducted several targeted casts (where gliders and ships started profiles simultaneously) and non-targeted casts (unplanned matchups where gliders and ships CTD-profiles were within an acceptable range of each other). Bottle samples were collected on all ship CTD profiles. For calibration purposes, we evaluated and determined that casts within 5 km and 12 hours of each other were considered glider ship matchups. These matchups exhibited strong correlation (linear regression r^2 = 0.95).Variables calibrated were salinity, chlorophyll concentration and oxygen concentration. Doombar’s mission was slightly modified 3 times during the 4-month deployment: 1 – Sampling around a 12 km triangle at BN0 (centred at 10.80°E, 18.25°S) from 19/02/2018-27/03/2018: Once the glider reached the site (BN0), it was tasked to survey a triangle with 12 km side, centred at that location. The location of the triangle was chosen based on low currents to help constrain advective processes and the predominantly westward surface currents in the region . The 12km sided triangle was chosen based on the time it took the glider to do a complete circuit, aiming for the glider to take around 1.5 days around the triangle. 2 – Sampling around a 12 km triangle at BN (centred at 10.95°E, 18.05°S) from 27/03/2018-08/06/2018: Given that the mission was to survey a low oxygen region, and oxygen concentrations monitored by the glider weren’t consistently low, on March 26th the glider was re-tasked to establish a new triangle (BN) centred at 10.95°E, 18.05°S, Northeast of the initial sampling site, where lower oxygen concentrations were expected. 3 – Station-keeping (“virtual-mooring”) 1.5km North of BN from 08/06/2018-19/06/2018: Throughout its deployment, Doombar gradually reduced its forward speed from about 4km per 1000m dive to about 1.5km. This meant that the glider could no longer cover the triangle in less than 2 days. So, while the ship was in the vicinity, Doombar was assigned a station keeping mission 1.5 km from the cruise main station, to not only avoid the risk of hitting the glider, but also so that any ship data could contribute to validating glider sensor data. Further information on sensor validation can be found in the netcdf file as well as documented in (Lovecchio et al, 2022)-[https://doi.org/10.1029/2022JC019063]. 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.

Two quality controlled datasets here archived were collected during the oceanographic cruise MEIO that held in October-November 2022 over the South Western Indian Ocean, onboard S.A. Agulhas II. The first dataset is composed of continuous vertical profiles of the 12 oceanographic stations. The profiles have a resolution of 1dbar. The parameters reported in this data set are: pressure (in dbar), in-situ temperature (in °C), practical salinity, dissolved oxygen concentration (in µmol/kg), fluorescence of calibrated chlorophyll-a fluorescence (in µg/L), nitrate concentration (in µmol/kg) and particle attenuation @660nm (in 1/m). The second dataset is composed of discrete samples collected during the 12 stations. The parameters are the sensors measurements of every samples, dissolved oxygen concentration measured by the Winkler method (in µmol/kg), practical salinity measured by Autosal, concentration of silicate (in µmol/kg), concentration of phosphate (in µmol/kg) , concentration of nitrite (in µmol/kg), concentration of nitrate (in µmol/kg), concentration of pigments (processed by HPLC). These datasets aim to contribute to the extension of the One-Argo programme in the southwestern area of the Indian Ocean through the deployment of a significant number of floats; and to collect reference measurements through a multi-instrumented CTD rosette, allowing in particular to calibrate the robots’ sensors, just before their deployment. The two datasets were collected in concomitancy with the deployment of 29 One-Argo floats (WMO numbers : 5906536, 6903149, 4902620, 6903088, 6903148, 6990505, 5906970, 7901013, 4902626, 6903150, 5906972, 6903031, 5906540, 5906969, 4902623, 6990503, 3902471, 5906539, 6990504, 1902572, 5906537, 4902628, 7901003, 3902472, 6903033, 5906538, 1902573, 6903084, 5906971). 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.

EMSO-LO (European Multidisciplinary See floor Observatory and water column, Western Ligurian Site) is a second generation permanent submarine observatory deployed offshore of Toulon, France. This submarine network is part of the LSPM (Laboratoire Sous-Marin Provence Méditerannée, https://www.km3net.org/) which has a modular topology designed to connect up to 120 neutrino detection units. The Earth and Sea Science (ESS) instrumentation connected to KM3NeT is based on two complementary components: an Instrumented Interface Module (MII), an autonomous mooring line (ALBATROSS) and a Scientific Junction Box (BJS, developed by Ifremer). On the ocean floor, instruments and plateforms can be connected to the BJS whose role is to supply energy and internet connection to the instruments of the site. Among the most relevant novelties, BathyBot is an underwater robot that joined the observatory site for several years, and deployed from a structure called BathyDock. BathyBot - A benthic robot to see the invisible in the depths of the Mediterranean Sea is a remotely-operated, cabled exploration robot. It is dedicated to long-term monitoring of deep-sea environmental variables (oxygen, temperature, salinity, pressure, current - the fluorimeter data flux is available through the aquadopp data flux) as well as biology, thanks to two different cameras (images available through a citizen science project http://ecotaxa.obs-vlfr.fr/). In particular, BathyBot will enable to see the bioluminescence emitted by marine organisms and better understand its ecological role. 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.

Data related to the article: Shelf Water Export at the Brazil-Malvinas Confluence Evidenced From Combined In-situ and Satellite Observations. By Gaston Manta, Sabrina Speich, Marcelo Barreiro, Romina Trinchin, Camila de Mello, Remi Laxenaire and Alberto R. Piola. Oceanographic dataset of CTD, TSG, and ADCP campaign in Uruguay during April-May 2016 (see the paper). CTD_Manta_etal_2022.nc contains the 82 CTD profiles There are matrices of 4219 * 82. 4219 is the maximum pressure reached by a station. The rest is filled with NaNs. TSG_Manta_etal_2022.csv is the TSG data with a 10 minute centered moving average and a coarse calibration of the fluorometer (see the paper). ADCP_Manta_etal_2022.nc are u and v velocities from the hull-mounted ADCP, matrices of depth (50)x time(18500) processed with cascade and tide corrected. Water_samples_Manta_etal_2022.csv Contains nutrients and chlorophyll-a at 5m depth. (Time is always in MatLab datenum format and in year-month-day-hour-minute-second) You can find more details about the data in the paper and also here http://data.utm.csic.es/geonetwork/srv/eng/catalog.search#/metadata/urn:SDN:CSR:LOCAL:29SG20160408 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.

In April 2017, two Ice Atmosphere Arctic Ocean Observing System platforms (IAOOS 23 and IAOOS 24) were deployed near the North Pole. Over the next 8 months, they meandered southwards with the ice in the Transpolar Drift, collecting measurements in the upper 250 m of Amundsen Basin, Nansen Basin and Fram Strait. The ocean profilers are PROVOR SPI (from French manufacturer NKE), which includes a Seabird SBE41 CTD (Conductivity, Temperature, Depth) and a dissolved oxygen (DO) Aandera 4330 optode. IAOOS 23 also featured a bio-optics sensor suite and a submersible ultraviolet nitrate analyzer (SUNA, Satlantic-Seabird Inc.). The bio-optics sensor suite (called Pack Rem A) combines a three-optical-sensor instrument (ECO Triplet, WET Labs Inc.) and a multispectral radiometer (OCR-504, Satlantic Inc.). The present dataset is composed of chlorophyll-a fluorescence, backscatter, irradiances (at 412, 490 and 555 nm), photosynthetically active radiation (PAR), nitrate and colored-dissolved organic matter data from the IAOOS 23 platform, as well as composites of absolute salinity, conservative temperature and apparent oxygen utilization data from both profilers. The profilers were set to perform two upward profiles a day from 250 m starting at approximately 6 am and 6 pm. In this dataset, chlorophyll-a, PAR and irradiances were corrected with a shift to set dark values to zero. Nitrate was interpolated vertically every 5 m, and all other parameters were interpolated vertically every 0.5 m. 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 datasets contains selected data from the underwater glider missions in Eastern Mediterranean performed in April-May and in August 2023 by Institute of Marine Sciences, Middle East Technical University (METU-IMS). The glider was donated to METU-IMS by Is Bankasi - the national commercial bank in Turkey. The underwater glider SeaExplorer X2 of ALSEAMAR is equipped with the following instruments: 1) RBRlegato³ C.T.D (non-pumped flow) with temperature, conductivity and pressure sensors; 2) JFE Advantech Co. Rinko Fast Optical DO sensor; 3) Wet Labs ECO Puck (fluorescence and turbidity); 4) Sea-Bird Scientific Deep SUNA Ocean Nitrate Sensor; 5) Altimeter. The research area is between mainland and Cyprus bounded by a rectangle with coordinates 35.52°-36.1°N, 33.2°-33.5°E. The first mission with internal number 16 was carried out in period April, 26 – May, 16, 2023, the second mission with internal number 20 was carried out in period August, 2 – August, 27, 2023. The first and last transects from each mission are included in the dataset. The dataset is submitted as zip-archive containing 110 .gz files. Each .gz file contains instrument output acquired within one glider dive cycle.