This dataset represents the integrated assessment of hazardous substances in the Baltic Sea in 2016-2021. This dataset displays the result of the assessment in HELCOM Assessment unit Level 3 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and offshore areas).

This dataset represents the underlying data on core indicator Hexabromocyclododecane (HBCDD). The core indicator evaluates the status of the marine environment based on concentrations of Hexabromocyclododecane (HBCDD) in sediment. Quantitative threshold values are used to evaluate if core indicators status is Achieve, Fail or Not assessed. The threshold value is an environmental quality standard (EQS), derived at EU level as a substance included on the priority list under Directive 2008/105/EC. This dataset displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas and division of the coastal areas by WFD water types or water bodies) Attribute information: "region" = name of region "country" = country "station" = Unique code for station "stationNam" = name for the station "determinan" = determinant parameter "detGroup" = the grouping of determinants used to display the results "_shape" = shape used to map assessment results "colour" = colour used to map assessment results "l3area" = HELCOM assessment unit on scale 3 "l4area" = HELCOM assessment unit on scale 4 "nyall" = total number of years of data "nyfit" = number of years of data used in the assessment "nypos" = number of years with at least one measurement above the limit of detection "lastyear" = most recent year of data "prtrend" = the significance of the change over the most recent 20 years; for the assessment conducted in November 2017 and published in June 2018, this is the period 1996-2016 "rtrend" = annual ‘linear’ change over the most recent 20 years "meanLY" = fitted value in last monitoring year "clLY" = upper one-sided 95% confidence limit on fitted value in last monitoring year "EQS" = Threshold value "EQSdiff" = difference between clLY and EQS "EQSbelow" = whether the mean value in the last monitoring year is significantly below EQS

This core indicator evaluates the status of the marine environment based on concentrations of heavy metal cadmium (Cd) in seawater, biota and sediments. Quantitative thresholds are used to evaluate if core indicators status is "Achieve", "Fail" or "Not assessed". Threshold values are based on Environmental quality standards (EQS), defined at EU level for substances included in the priority list under the Water Framework Directive. This dataset displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas and division of the coastal areas by WFD water types or water bodies). Attribute information: "OBJECTID" = Object identification "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "Descriptio" = Description of the HELCOM scale 4 assessment unit "AULEVEL" = Assessment unit level used for the indicator "Contamination ratio in biota" = Contamination ratio in biota for this substance "Status in biota" = Status of the indicator in biota (“Achieve”, “Fail” or “Not assessed”) "Contamination ratio in sediment" = Contamination ratio in sediment for this substance "Status in sediment" = Status of the indicator in sediment (“Achieve”, “Fail” or “Not assessed”) "Contamination ratio in water" = Contamination ratio in water for this substance "Status in water" = Status of the indicator in water(“Achieve”, “Fail” or “Not assessed”) "Overall Status" = Overall Status of the indicator according to one-out-all-out (“Achieve”, “Fail” or “Not assessed”)

This dataset represents the underlying water data on core indicator Perfluorooctane sulphonate (PFOS). The core indicator evaluates the status of the marine environment based on concentrations of perfluorooctane sulphonate (PFOS) in Baltic Sea fish and in a few assessment unit using the secondary matrix seawater. Quantitative thresholds are used to evaluate if core indicators status is Achieve, Fail or Not assessed. Good status is achieved when the concentrations of PFOS are below the threshold value. This dataset displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas and division of the coastal areas by WFD water types or water bodies). Attribute information: "region" = name of subbasin "country" = country "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter "detGroup" = the grouping of determinands used to display the results "filtered" = Filtered or unfiltered water sample used in analysis "_shape" = shape used to map assessment results "colour" = colour used to map assessment results "l3area" = HELCOM assessment unit on scale 3 "l4area" = HELCOM assessment unit on scale 4 "nyall" = total number of years of data "nyfit" = number of years of data used in the assessment "nypos" = number of years with at least one measurement above the limit of detection "lastyear" = most recent year of data "prtrend" = the significance of the change over the most recent 20 years; for the assessment conducted in November 2017 and published in June 2018, this is the period 1996-2016 "rtrend" = annual ‘linear’ change over the most recent 20 years "meanLY" = fitted value in last monitoring year "clLY" = upper one-sided 95% confidence limit on fitted value in last monitoring year "EQS" = Threshold value "EQSdiff" = difference between clLY and EQS "EQSbelow" = whether the mean value in the last monitoring year is significantly below EQS

This dataset contains the in-situ monitoring data used for calculating eutrophication indicator results for following indicators: Chlorophyll-a 2018 Dissolved inorganic nitrogen 2018 Dissolved inorganic phosphorus 2018 Total nitrogen 2018 Total phosphorus 2018 Water clarity 2018 This dataset is extraction for 2011-2016 assessment period from HELCOM COMBINE database, which contains all HELCOM oceanographic monitoring data. Full COMBINE database can be accessed from dedicated web page Attribute information: "Cruise": Platform code of the monitoring cruise, which can be queried from http://vocab.ices.dk/ "Station": Station number "Year": Year of sampling event "Month": Month of sampling event "Day": Day of sampling event "Hour": Hour of sampling event "Minute": Minute of sampling event "Latitude": Latitude coordinate of the sampling location (WGS84 decimal degrees) "Longitude": Longitude coordinate of the sampling location (WGS84 decimal degrees) "BotDepth": Bottom depth (m) of sampling location "Secchi": Secchi depth at sampling location "StationNam": Station name from ICES Station dictionary "Assessment" = HELCOM assessment unit ID "Depth": Sampling depth (m) "Temperature": Temperature (ºC) "Salinity": Salinity "Oxygen": Oxygen (ml/l) "Phosphate": Phosphate (umol/l) "TotalPhos": Total phosphorus (umol/l) "Silicate": Silicate (umol/l) "Nitrate": Nitrate (umol/l) "Nitrite": Nitrite (umol/l) "Ammonium": Ammonium (umol/l) "TotalNitr": Total nitrogen (umol/l) "HydrogenS": Hydrogen sulphide (umol/l) "pH": pH "Alkalinity": Alkalinity (mEq/l) "Chlorophyl": Chlorophyll-a (ug/l)

The Diatom/Dinoflagellate index (Dia/Dino index) reflects the dominance patterns in the phytoplankton spring bloom. It has high relevance for the pathway of the food into the pelagic or benthic food web. In principle, the indicator is applicable in all coastal and open sea assessment units, except lagoons, large river plumes and the Bothnian Bay; however, thresholds for the good status are defined only for the southern and central Baltic Sea up to now. The indicator is not yet agreed as a HELCOM core indicator but is tested in the HOLAS II project for the Eastern Gotland Basin. In this assessment unit, the average Dia/Dino index of the years 2011-2016 was just below the threshold value of 0.5 for good status. The confidence of the indicator evaluation depends on the data frequency. The data have to represent the diatom and dinoflagellate blooms adequately. If the diatom bloom is not sufficiently represented in the data, an alternative Dia/Dino index may be applied, based on silicate consumption data. This indicator is robust; its calculation is simple and traceable. The phytoplankton monitoring is operational in the whole Baltic Sea using methods prescribed in the COMBINE manual. Currently, a high quality of the data is assured by the experts of the HELCOM Phytoplankton Expert Group (PEG). The basic data are phytoplankton biomass data, determined as explained in the HELCOM COMBINE manual, originating from the depth of 0 – 10 m. Also silicate data were used that were taken parallel to the phytoplankton sampling. Diatom-dinoflagellate ratio dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "HELCOM_ID" = ID of the HELCOM scale 2 assessment unit "Area (km2)" = Area of the HELCOM assessment unit "Name" = Name of the HELCOM scale 2 assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Threshold value" = Threshold value of indicator "Unit" = Unit of the indicator "Indicator value" = Result of the indicator "AULEVEL" = Assessment unit level used for the indicator

This core indicator evaluates the status of the marine environment based on concentrations of radioactive substances (Cs-137) in seawater and biota. Quantitative thresholds are used to evaluate if core indicators status is "Achieve", "Fail" or "Not assessed". Good status is achieved when concentrations reach levels measured before the Chernobyl accident in 1986. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins) for seawater. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 2 assessment unit "level_2" = name of the HELCOM scale 2 assessment unit (subbasin) "area_km2" = Area of HELCOM assessment unit "Indicator" = name of the indicator "Unit" = Unit used for the measured parameter "Type" = type of the indicator "Threshold value" = Threshold value for the subbasin "Indicator value" = Indicator value (result) for the subbasin "STATUS" = Status of the indicator in seawater (“Achieve”, “Fail” or “Not assessed”)

This dataset represents the Integrated biodiversity status assessment for benthic habitats using the BEAT tool. Status is shown in five categories based on the integrated assessment scores obtained in the tool. Biological Quality Ratios (BQR) above 0.6 correspond to good status. The assessment in open sea areas was based on the core indicators ‘State of the soft-bottom macrofauna community’ and ‘Oxygen debt’. Coastal areas were assessed by national indicators, and may hence not be directly comparable with each other. This dataset displays the result of the integrated biodiverity status in HELCOM Assessment unit Scale 4 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas and division of the coastal areas by WFD water types or water bodies). Attribute information: "BQR" = Biological Quality Ratio "Confidence" = Confidence of the assessment "HELCOM_ID" = id of the HELCOM assessment unit "country" = name of the country / opensea "level_2" = HELCOM sub-basins (name of the scale 2 assessment unit) "Name" = Name of the coastal assessment unit on scale 4 "AULEVEL" = scale of the assessment units "type_descr" = Name of the HELCOM scale 4 assessment unit "SAUID" = ID number for the spatial assessment unit "EcosystemC" = Ecosystem component assessed "Confiden_1" = Confidence of the assessment (0-1, higher values mean higher confidence) "Total_numb" = Number of indicators used in assessment "Area_km2" = Area of assessment unit (km2) "Confiden_1" = Confidence level of the assessment (scores < 0.5 = low, 0.5 - 0.75 = intermediate, > 0.75 = high) "STATUS" = Integrated status category (0-0.2 = not good (lowest score), 0.2-0.4 = not good (lower score), 0.4-0.6 = not good (low score), 0.6-0.8 = good (high score), 0.8-1.0 = good (highest score))

The assessment results for waterbirds for the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3) contains the following datasets: Integrated Biodiversity Status Assessment for Waterbirds, Integrated Biodiversity Status Assessment for surface-feeding birds, Integrated Biodiversity Status Assessment for pelagic-feeding birds, Integrated Biodiversity Status Assessment for benthic-feeding birds, Integrated Biodiversity Status Assessment for wading birds, and Integrated Biodiversity Status Assessment for grazing birds. Status is shown in five categories based on the integrated assessment scores obtained in the tool. Biological Quality Ratios (BQR) above 0.6 correspond to good status. The datasets were created using the BEAT tool. https://github.com/helcomsecretariat/BEAT Attribute information: "Birds_ag" = Birds group area "GroupName" = Birds group area name "BQR" = Biological Quality Ratio "Conf" = Confidence of the assessment (0-1, higher values mean higher confidence) "ConfClass" = Confidence class "Status" = Integrated status category (0-0.2 = not good (lowest score), 0.2-0.4 = not good (lower score), 0.4-0.6 = not good (low score), 0.6-0.8 = good (high score), 0.8-1.0 = good (highest score)) "ProportionSpecies" = Proportion of species in good status "SAUlevel" = Spatial assessment unit ID in which the assessment status took place "EcosystemComponent" = Ecosystem component assessed

This dataset represents the underlying data on core indicator Seasonal succession of dominating phytoplankton groups 2018. The core indicator evaluates phytoplankton community structure to determine whether it reflects good environmental status. Quantitative thresholds are used to evaluate if core indicators status is Good, Not good or Not assessed. Attribute information: "Code"= ID of HELCOM level 2 assessment unit "Assessment" = Name of HELCOM level 2 assessment unit "Station" = Name of station "Lat" = Latitude of station in WGS 84 decimal degrees "Lon" = Longitude of station in WGS 84 decimal degrees "Data_avail" = Data availability period (years) "Reference" = Reference period (years) "Data_provi" = Data provider organisation "Country" = Data provider country "Station_na" = Station name "Date" = Sampling date and time "Year" = Year of sampling "Month" = Month of sampling "Cyano" = Cyanobacteria "Dino" = Dinoflagellates "Diatoms" = Diatoms "Meso_rub" = Mesodinium rubrum "CyanoIn" = "DinoIn" = "DiatomsIn" = "MesoRubIn" =