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.

This set of CTD measurements places the fresh water discharge into the sea, which is located in Punta Esmeralda in the City of Playa del Carmen, State of Quintana Roo, in the Mexican Caribbean Sea. For these measurements two measuring instruments were used; a CTD for temperature and salinity profiles and a USGS type AA current meter to measure discharge to the sea, applying two methodologies for the measurement of volumetric flow according to FAO, (2009). Punta Esmeralda is a beach site that has three springs on the beach which form a freshwater lagoon about 60 meters long by 25 wide and a deep part of 1.6 meters. This lagoon is located at the coordinates 20.648372 ° N 87.050909 ° W. The discharge of water forms a small stream with a stream 6 meters wide with a bathymetric profile with a maximum depth of 0.40 m. These dimensions change over time due to natural and artificial processes. The fresh water discharge to the sea has an average flow of 0.2142 m3 /s , at an average speed of 0.1305 m /s. The sampling points with the CTD were a total of 61 and were distributed throughout the lagoon, the output of the three largest springs and a small "cenote" that is located about 76 meters away from the beach, were also performed sampling points in the sea at a distance of 100 meters from the coast and 2 meters deep. The salinity ranges measured in the springs was 4 UPS and it was increasing to the sea with 35 UPS. With temperatures in the springs from 25.8 ° C to 30.8 ° C in the sea.   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 campaign was carried out on May 15, 2021 on the route between Puerto Juárez and the Arrowsmith Bank course or “Bajo del Este”, as the fishermen call it. The bank is located 40 km east of Punta Cancun at coordinates 21°05'00''N-86°28'00''W. The ship's captain Guillermo Antonio Carrillo Corzo alias the "Teacher", a pilot (Cap. Watermelon) and a sailor (El Chalán). The goal was carry out temperature and salinity measurements in the water column at each of the CTD stations. Direction: 10 stations with a separation of 4 km between each one were planned. Stations 1 to 6 were covered without difficulty; however, at station 7 the waves and the current increased their intensity considerably, so no progress was made to the following stations. the diagram salinity temperature profiles of each station (aligned West to East) The salinity is between 35 and 36 UPS and in turn from 28 °C to 25.5 °C. The depth ranges at the stations were from 1 to 57 m deep. 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 May 2018, an unprecedented long and intense seismic-volcanic crisis broke out off the island of Mayotte (Indian Ocean) and was associated with the birth of the Fani Maoré underwater volcano. Since then, an integrated observation network has been created (REVOSIMA), with the given objective of monitoring and better understanding underwater volcanic phenomena. Recently, an unmanned submarine glider (SeaExplorer) has been deployed to supplement the data obtained during oceanographic surveys (MAYOBS) which are carried out on an annual basis. This glider is operated by ALSEAMAR and performed a continuous monitoring of 30 months of the water column with the objective to acquire hydrological properties, water currents and dissolved gas concentrations. This monitoring already showed that it is feasible and valuable to measure autonomously, continuously and at a high spatio-temporal scale, physical (TEMP, SAL, water currents) and biogeochemical parameters (O2, CH4, PCO2, bubbles/droplets, vertical speeds) over several months from a SeaExplorer glider. In particular, innovating sensing capabilities (e.g., MINI-CO2, ADCP) have shown a great potential in the context of the Mayotte seismic volcano crisis, despite technical challenges (complex algorithms, sensor capabilities, etc.). This dataset provides these physical and biogeochemical parameters from September 17, 2021 to April 02, 2024 and the quality flags associated.    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.

A geotechnical survey campaign was undertaken within the vicinity of the Westermost Rough Offshore Wind Farm. This was supported by a preliminary review of acoustic data and assessment for the presence of Annex I reefs to minimise the risk of potential damage to protected features. Following the review of existing data, a drop down video survey protocol was developed (EMU, 2011) and approved by the Marine Management Organisation (MMO). Part of this protocol identified that a number of proposed geotechnical sampling sites were likely to be in the vicinity of potential Annex I reefs and therefore warranted field ground-truthing by means of drop down video to verify the presence and status of these features. The video ground-truthing survey has now been completed. Drawing upon the findings of this survey, the 2012 EMU report present within this series provides an update of the assessment of the potential Annex I reefs present at the proposed geotechnical sample locations and fulfils condition 3.1.1 of the Marine Licence (Licence L/2011/001075). The aim of the 2013 Fugro EMU document also present within this series was to satisfy Marine Licence condition 31.22 and to address the responses from the MMO regarding the Annex I reef features (letter ref: REN024, dated 12th April 2013, and 21st June 2013). The objectives were to assess the impacts (direct and indirect) of the construction activities on the potential Annex I features. The objectives of this report were to: 1. Assess the direct impact (loss of habitat) of each of the construction activities; 2. Assess the associated indirect impacts (increase in sediment smothering, and suspended sediment concentrations. 3. Assess the cumulative impacts of all construction activities.

The current dataset contains data on 63 Hz and 125 Hz 1/3 octaves of continuous underwater noise (Descriptor D11.2) recorded on four different locations in two periods (during off tourist season) of December-2018

This data set contains station data of top-to-bottom oceanic current measurements performed with Lowered Acoustic Doppler Current Profilers (LADCP) during the Med-SHIP cruise TAlPro2022 (Toulone - La Spezia, RV Belgica, 17/05/2022 - 26/05/2016). The LADCP devices in use were a downward and an upward-looking ADCP of type Teledyne RDI Workhorse Monitor 300 kHz. Station data of zonal and meridional oceanic velocities are reported in [cm/s] on a 4 m vertical grid.

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.

The Reykjanes Ridge is a major topographic feature of the North-Atlantic Ocean. It lies in a central position along the main paths followed by the upper and lower limbs of the Meridional Overturning Cell (MOC), which contributes at moderating the European climate in creating a transport of heat toward the North Atlantic. Our hypothesis is that the Reykjanes Ridge influences the main components of the upper and lower limbs of the MOC because it is a strong constraint on the horizontal and vertical circulation, it impacts the water mass distribution and evolution and it is a region of intense turbulent mixing. The objective of the RREX project is to conduct a process study in order to better understand the role of the Reykjanes Ridge on the dynamics and water mass transformation in the subpolar gyre and ultimately on the MOC. This project relied on two hydrographic cruises carried out in 2015 and 2017 to acquire the adequate dataset to (1) provide a synoptic high-resolution and full depth survey to monitor the flow along and across the ridge, (2) to quantify the variability of the vertical and horizontal structure of the currents parallel to the ridge at daily to seasonal time-scales and (3) to provide sufficient turbulence observations to monitor the heterogeneous and intermittent mixing processes. This dataset currently provides the measurements from the 133 CTDO2 stations realized during the RREX2015 cruise, carried out from the 5th of June to the 10th of July 2015. At each station, the following measurements are available: (1) pressure, temperature, conductivity and dissolved oxygen measurements with a CTDO2 probe, (2) salinity and oxygen concentration data from sea water samples at 28 levels. It also provides OS38 and OS150 S-ADCP data acquried in transit during the RREX2015 cruise. The two datasets were processed and adjusted following Petit et al. 2018 [http://doi.org/10.13155/53471].   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 data set contains the post-processed current profiles collected by means of a vessel-mounted ADCP (on the Belgia vessel RV BELGICA) in the Western Mediterranean Sea during May 2022. The TAlPro2022 cruise was part of the Med-SHIP programme. During the whole campaign a VM-ADCP (RDI Ocean Surveyor, 75 KHz) worked along the ship route. The depth range of the current profiler is about 725 m. Data acquisition is carried out using the RDI VMDAS software vers. 1.50.19. The number of bins has been set to 80, with a bin size of 10 m . The instrument ran in narrowband mode and was controlled by computers using the conventional RDI VMDAS software under a MS Windows system with a pinging set to be as fast as possible. No interferences with other used acoustical instruments were observed.