Dataset contains bio-optical measurements carried out at Utö Atmospheric and Marine research station, from spring 2017 to spring 2018. Dataset includes continuous measurements of temperature, salinity, O2, fluorescence for Chlorophyll, phycocyanin, phycoerythrin and CDOM, spectral fluorescence and FRRF fluorometry from a flow-through system (sampling depth -5 m). Data set also includes 3-4 1-week campaigns to measure exctracted Chlorophyll, spectral absorption and fluorescence, primary production and nutrients.

Dataset contains phycoeythrin fluorescence records during transects of ferry Finnmaid 25.5–31.8.2016 (four times per week) between Helsinki and Travemunde. Fluorescence was measured 20 second intervals using Microflu-red (Trios Gmbh) and Unilux -PE (Chelsea Technologies) fluorometers, installed in flow-through system. Water samples were collected weekly from three locations and ell counts of phycoerythrin containing species were carried out using epifluoresence microsopy (picocyanobacteria) and flowCam (larger cells).

Dataset contains ferrybox (ferry Silja Serenade) measurements between Helsinki and Stockholm from spring 2017 to spring 2018. Dataset includes continuous measurements of temperature, salinity, O2, fluorescence for Chlorophyll, phycocyanin, and CDOM from a flow-through system (sampling depth -5 m). Data set also includes monthly/weekly measurements of extracted Chlorophyll.

This datasets contains data from continuous measurements along the Tavastland (formerly TransPaper) Serenade ferry line between Oulu-Kemi and Lübeck. At the depth of three meter under the water surface, sea water is constantly pumped into an on-board mini-laboratory. Parameters collected include chloropyll a, phycocyanin and CDOM fluorescence and turbidity.

Units: umol/l. Method: spatial interpolation produced with DIVA (Data-Interpolating Variational Analysis). URL: http://modb.oce.ulg.ac.be/DIVA. Comment: Every year of the time dimension corresponds to a 10-year centred average for each season : - winter season (December-February), - spring (March-May), - summer (June-August), - autumn (September-November). Diva settings: Snr=1.0, CL=0.7.

Units: umol/l. Method: spatial interpolation produced with DIVA (Data-Interpolating Variational Analysis). URL: http://modb.oce.ulg.ac.be/DIVA. Comment: Every year of the time dimension corresponds to a 10-year centred average for each season : - winter season (December-February), - spring (March-May), - summer (June-August), - autumn (September-November). Diva settings: Snr=1.0, CL=0.7.

Units: umol/l. Method: spatial interpolation produced with DIVA (Data-Interpolating Variational Analysis). URL: http://modb.oce.ulg.ac.be/DIVA. Comment: Every year of the time dimension corresponds to a 10-year centred average for each season : - winter season (December-February), - spring (March-May), - summer (June-August), - autumn (September-November). Diva settings: Snr=1.0, CL=0.7

Units: umol/l. Method: spatial interpolation produced with DIVA (Data-Interpolating Variational Analysis). URL: http://modb.oce.ulg.ac.be/DIVA. Comment: Every year of the time dimension corresponds to a 10-year centred average for each season : - winter season (December-February), - spring (March-May), - summer (June-August), - autumn (September-November). Diva settings: Snr=1.0, CL=0.7.

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 (49 parameters), and covers the Baltic Sea with 3818 CDI records divided per matrices: 1358 biota (396 Vertical profiles and 962 Time series),906 water profiles, 2510 sediment profiles. Vertical profiles temporal range is from 1985-04-16 to 2016-09-27. Time series temporal range is from 1972-05-02 to 2017-10-30. Data were aggregated and quality controlled by ‘Swedish Meteorological and Hydrological Institute (SMHI)’ from Sweden. 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 49 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

Units: umol/l. Method: spatial interpolation produced with DIVA (Data-Interpolating Variational Analysis). URL: http://modb.oce.ulg.ac.be/DIVA. Comment: Every year of the time dimension corresponds to a 10-year centred average for each season : - winter season (December-February), - spring (March-May), - summer (June-August), - autumn (September-November). Diva settings: Snr=1.0, CL=0.7.