Gridded product for visualization of Water body chlorophyll-a in the Western part of Black Sea generated by DIVA 4.6.11 using all EMODNET Chemistry data from 2000 to 2014. Depth range (IODE standard depths): 0, -5, -10, –20m. DIVA settings: signal-to-noise ratio and correlation length were estimated using data mean distance as a minimum (for L), and both parameters vertically filtered. Background field: the data mean value is subtracted from the data. Detrending of data: no. Advection constraint applied: no. Analysis: logaritmic transformation. Every year of the time dimension corresponds to a 10-year centred average for each season: - winter: December - February, - spring: March - May, - summer: June - August, - autumn: September - November Units: mg/m^3

Gridded product for visualization of Water body ammonium in the Black Sea - West Slope generated by DIVA 4.6.9 using all EMODNET Chemistry data from 1980 to 2013. Depth range (IODE standard depths): 0 – 75m. DIVA settings: signal-to-noise ratio and correlation length were estimated using data mean distance as a minimum (for L), and both parameters vertically filtered. Background field: the data mean value is subtracted from the data. Detrending of data: no. Advection constraint applied: no. Every year of the time dimension corresponds to a 10-year centred average for each season: - winter: December - February, - spring: March - May, - summer: June - August, - autumn: September – November Units: umol/l

Gridded product for visualization of Water body nitrate plus nitrite in the Black Sea generated by DIVA 4.6.9 using all EMODNET Chemistry data from 1976 to 2013. Depth range (IODE standard depths): 0 – 150m. DIVA settings: signal-to-noise ratio and correlation length were estimated using data mean distance as a minimum (for L), and both parameters vertically filtered. Background field: the data mean value is subtracted from the data. Detrending of data: no. Advection constraint applied: no. Every year of the time dimension corresponds to a 10-year centred average for each season: - winter: December - February, - spring: March - May, - summer: June - August, - autumn: September – November Units: umol/l

Gridded product for visualization of Water body dissolved oxygen concentration in the Black Sea generated by DIVA 4.6.11 using all EMODNET Chemistry data from 1970 to 2014. Depth range (IODE standard depths): 0 – 250m. DIVA settings: signal-to-noise ratio and correlation length were estimated using data mean distance as a minimum (for L), and both parameters vertically filtered. Background field: the data mean value is subtracted from the data. Detrending of data: no. Advection constraint applied: no. Every year of the time dimension corresponds to a 10-year centred average for each season: - winter: December - February, - spring: March - May, - summer: June - August, - autumn: September – November Units: umol/l

EMODnet Chemistry aims to provide access to marine chemistry data sets and derived data products concerning eutrophication, ocean acidification and contaminants. The chemicals chosen reflect importance to the Marine Strategy Framework Directive (MSFD). This regional aggregated dataset contains all unrestricted EMODnet Chemistry data on contaminants (48 parameters), and covers the Black Sea with 21504 CDI records divided per matrices: 7 biota profiles, 19677 water profiles, 1820 sediment profiles. Vertical profiles temporal range is from 1974-08-24 to 2017-10-06. Data were aggregated and quality controlled by ‘National Institute for Marine Research and Development "Grigore Antipa"’ from Romania. Regional datasets concerning contaminants are automatically harvested. Parameter names in these datasets are based on P01, BODC Parameter Usage Vocabulary, which is available at: http://seadatanet.maris2.nl/bandit/browse_step.php . Each measurement value has a quality flag indicator. The resulting data collections for each Sea Basin are harmonised, and the collections are quality controlled by EMODnet Chemistry Regional Leaders using ODV Software and following a common methodology for all Sea Regions. Harmonisation means that: (1) unit conversion is carried out to express contaminant concentrations with a limited set of measurement units (according to EU directives 2013/39/UE; Comm. Dec. EU 2017/848) and (2) merging of variables described by different “local names”, but corresponding exactly to the same concepts in BODC P01 vocabulary. The harmonised dataset can be downloaded as ODV spreadsheet (TXT file), which is composed of metadata header followed by tab separated values. This worksheet can be imported to ODV Software for visualisation (More information can be found at: https://www.seadatanet.org/Software/ODV ). The same dataset is offered also as XLSX file in a long/vertical format, in which each P01 measurement is a record line. Additionally, there are a series of columns that split P01 terms in subcomponents (measure, substance, CAS number, matrix...).This transposed format is more adapted to worksheet applications users (e.g. LibreOffice Calc). The 48 parameter names in this metadata record are based on P02, SeaDataNet Parameter Discovery Vocabulary, which is available at: http://seadatanet.maris2.nl/v_bodc_vocab_v2/vocab_relations.asp?lib=P02 . Detailed documentation will be published soon. The original datasets can be searched and downloaded from EMODnet Chemistry Download Service: https://emodnet-chemistry.maris.nl/search

EMODnet Chemistry aims to provide access to marine chemistry datasets and derived data products concerning eutrophication, acidity and contaminants. The importance of the selected substances and other parameters relates to the Marine Strategy Framework Directive (MSFD). This aggregated dataset contains all unrestricted EMODnet Chemistry data profiles on eutrophication and acidity, and covers: the Artic Ocean, the North East Atlantic, the Greater North Sea and Celtic Seas, the Baltic Sea, the Mediterranean Sea and the Black Sea. ITS-90 water temperature and water body salinity variables have also been included ('as are') to complete the eutrophication and acidity data. If you use these variables for calculations, please refer to SeaDataNet for the quality flags: https://www.seadatanet.org/Products/Aggregated-datasets. This European dataset is the result of the aggregation of the regional datasets concerning eutrophication and acidity present in EMODnet Chemistry. The regional datasets are automatically harvested, and the resulting collections are aggregated and quality controlled using ODV Software and following a common methodology for all sea regions ( https://doi.org/10.13120/8xm0-5m67). Parameter names are based on P35 vocabulary, which relates to EMODnet Chemistry aggregated parameter names and is available at: https://vocab.nerc.ac.uk/search_nvs/P35/. This process were regionally performed by: 'Institute of Marine Research - Norwegian Marine Data Centre (NMD)' (Norway), 'IFREMER / IDM / SISMER - Scientific Information Systems for the SEA' (France), 'Aarhus University, Department of Bioscience, Marine Ecology Roskilde' (Denmark), 'Swedish Meteorological and Hydrological Institute (SMHI)' (Sweden), 'Hellenic Centre for Marine Research, Hellenic National Oceanographic Data Centre (HCMR/HNODC)' (Greece) and 'National Institute for Marine Research and Development 'Grigore Antipa' (Romania). When not present in original data, water body nitrate plus nitrite was calculated by summing all nitrate and nitrite parameters. The same procedure was applied for water body dissolved inorganic nitrogen (DIN), which was calculated by summing all nitrate, nitrite, and ammonium parameters. Concentrations per unit mass were converted to a unit volume using a constant density of 1.25 kg/L. The aggregated dataset can be downloaded as an ODV collection.