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.

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.

ROV3G scientific cruise is dedicated to the morpho-tectonic study of the ligurian shelf, through the acquisition of bathymetric data and optical images with HROV Ariane. This cruise took place on R/V Europe in october 2021, and constituted a pedagogic project for the students of  Master 3G Recherche, Géologie et Géophysique, of Université Côte d'Azur (UCA), attached to Géoazur lab. The M2 students were in charge of the scientific project, they determined the goals of the cruise, took part in the acquisition and interpretation of the data.  During the 3 days cruise, we acquired bathymetric data at shallow depth on the continental shelf offshore Santo Stefano al Mare and San Lorenzo al Mare, along the Ligurian coast. The bathymetry on the continental shelf exhibits morphologies that are probably related to the Flyschs formation that is outcroping onshore (Stani et al., 2010), and that is partially capped by late quaternary deposits (as identified in seismic data and interpreted in Bozzano et al., 2006). Ridges identified as paleo-shorelines (paleo-beaches?) have been investigated with HROV ariane whose navigation is also published here. Videos are available on video.ifremer.fr Here we publish two bathymetric grids at high-resolution, calculated from the ME70 multibeam echosounder of R/V Europe, using GLOBE software (Poncelet et al., 2022). The shallowest part of the plateau is gridded in a 5 m digital elevation model (DEM), while the entire survey area is gridded at 10m resolution. The back-scatter maps, gridded at 6 m, produced with Sonarscope software (Augustin et al., 2022), are also available (raw and compensated). All grids are in WGS84 (EPSG:4326). The cruise report (written in french) is also available. 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.

Sound scattering layers (SSLs) are observed over a broad range of spatio-temporal scales and geographical areas. SSLs represent a large biomass, likely involved in the biological carbon pump and the structure of marine trophic webs. Yet, the taxonomic composition remains largely unknown for many SSLs. To investigate the challenges of SSL sampling, we performed a survey in a small study area in the Northern Bay of Biscay (France) by combining broadband and narrowband acoustics, net sampling, imagery and video recordings. In order to identify organisms contributing to the observed SSLs, we compared measured frequency spectra to forward predicted spectra derived from biological data. This dataset comprises the echo-integrated broadband acoustic data (in Sv(f)), the nets position and depth, and the abundance and the size of the catched organisms acquired during a specific operation of SSLs sampling during (Blanluet et al.)-[https://doi.org/10.1371/journal.pone.0223618]. 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.

These data consist of raw uncalibrated 38 and 120 kHz echosounder observations collected during a pelagic survey of the Chagos archipelago MPA (January 2015). Observations were collected from a pole-mounted system (transducers were fixed at a depth of 3m). Data include several transects recorded during the 19th January at the Swart seamount site (close to Diego Garcia). A calibration was conducted prior to the survey. Resultant transducer peak gain (G0) and Simrad correction factor (Sa) values were as follows: 38 kHz (power = 1000 W; pulse duration = 1.024 ms; G0 = 20.97 dB; Sa = -0.62 dB) and 120 kHz (power = 250 W; pulse duration = 1.024 ms; G0 = 24.5 dB; Sa = -0.29 dB).

Data collected as part of the Civil Hydrography Program. Area: HI1498 (Eastern Approach to Solent Data originally collected by Net Survey / MMT using a Kongsberg EM2040D (dual RX). Where this data intersected with Cefas' Marine Protection Area programme QPS FMGT was used to create a 1.0m resolution backscatter mosaic.

Data collected as part of the Civil Hydrography Program. Area: HI1499 (Southern Approach to Easter Solent Data originally collected by Net Survey / MMT using a Kongsberg EM2040D (dual RX). Where this data intersected with Cefas' Marine Protection Area programme QPS FMGT was used to create a 1.0m resolution backscatter mosaic.

Data collected as part of the Civil Hydrography Program. Areas used: HI1430 (Western Approach to the Dover TSS) Data originally collected by Net Survey / MMT using a Kongsberg EM2040D (dual RX). Where this data intersected with Cefas' Marine Protection Area programme QPS FMGT was used to create a 1.0m resolution backscatter mosaic.

mole concentration of dissolved molecular oxygen in sea water, temperature of sensor for oxygen in sea water, uncalibrated phase shift reported by oxygen sensor, calibrated phase shift reported by oxygen sensor, sea water temperature, sea water electrical conductivity, sea water pressure, mass concentration of chlorophyll a in sea water, volume absorption coefficient of radiative flux in sea water due to dissolved organic matter, volume scattering function of radiative flux in sea water 700