Samples were collected during the “Acoustics along the BRAzilian COaSt (ABRACOS)” oceanographic campaigns, carried out in Austral spring (30 August - 20 September of 2015 - ABRAÇOS1; Bertrand, 2015) and fall (9 April - 9 May of 2017 - ABRAÇOS 2; Bertrand, 2017) on board the French R/V ANTEA. Spring 2015 and fall 2017 are representative of canonical spring and fall conditions in terms of thermohaline structure and currents dynamics (Assunção et al., 2020; Dossa et al., 2021).  Nutrients (nitrite NO2, nitrate NO3, phosphate PO4 and silicate Si(OH)4) have been determined on seawater samples collected using Niskin bottles at different depths during the cruise. Up to 12 samples were collected at each station, depending on the station depth. Samples were collected and "pasteurised" (ie heated at 80C for 2h30 in an oven) to ensure their stability until the analysis was performed at the laboratory. The nutrients analysis has been achieved using the classical colorimetric method (Technicon analyzer). 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.

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.