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 seawater data on core indicator Radioactive substances: Cesium-137 in-fish-and-surface-seawater. The core indicator evaluates the state of the environment using the concentration of the radioactive isotope cesium-137 (137Cs) in herring, in flatfish and in surface waters. Quantitative thresholds are used to evaluate if core indicators Achieve or Fail Good status or if the status is Not assessed. Good status is achieved when concentrations reach levels measured before the Chernobyl accident in 1986 when the biota of the Baltic Sea received the most significant contribution to their level of artificial radionuclides, predominantly in the form of 137Cs. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "KEY" = MORS Database unique sample identifier "COUNTRY" = Code for country of observation "YEAR" = Year of observation "STATION" = Unique text that identifies the station "TDEPTH" = Bottom depth at sampling site (m) "SDEPTH" = Sampling depth (m) "ASSESSMENT" = Name of the HELCOM scale 2 assessment unit (subbasin) "NUCLIDE" = Nuclide measured "VALUE_Bq_m" = Value of measurement in Bq/m3

This dataset represents the Integrated biodiversity status assessment for fish used in State of the Baltic Sea – Second HELCOM holistic assessment 2011-2016. Status is shown in five categories based on the integrated assessment scores obtained in the BEAT tool. Biological Quality ratios (BQR) above 0.6 correspond to good status. The assessment is based on core indicators of coastal fish in coastal areas, and on internationally assessed commercial fish in the open sea. The open sea assessment includes fishing mortality and spawning stock biomass as an average over 2011–2016. Open sea results are given by ICES subdivisions, and are not shown where they overlap with coastal areas. Coastal areas results are given in HELCOM Assessment unit Scale 3 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas) Attribute information: "COUNTRY" = name of the country / opensea "Name" = Name of the coastal assessment unit, scale 3 (empty for ICES open sea units) "HELCOM_ID" = ID of the HELCOM scale 3 assessment unit (empty for ICES open sea units) "EcoystemC" = Ecosystem component analyzed "BQR" = Biological Quality Ratio "Conf" = Confidence (0-1, higher values mean higher confidence) "Total_indi" = Number of HELCOM core indicators included (coastal assessment units) "F__of_area = % of area assessed "D1C2" = MSFD descriptor 1 criteria 2 "Number_of" = Number of open sea species included "Confidence" = Confidence of the assessment "BQR_Demer" = Demersal Biological Quality Ratio "F_spec_Deme" = Number of demersal species included "Conf_Demer" = Confidence for demersal species "BQR_Pelagi" = Pelagic Biological Quality Ratio "F_specPela" = Number of pelagic species included "Conf_Pelag" = Confidence for pelagic species "ICES_SD" = ICES Subdivision number "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))

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 dataset represents the underlying biota data on core indicator Heavy metals – Lead.The core indicator evaluates the status of the marine environment based on concentrations of heavy metal Lead (Pb) in water, fish liver 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. The Core indicator 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 text that identifies the station "stationNam" = name for the station "determinan" = determinant parameter (PB = Lead) "detGroup" = the grouping of determinands used to display the results "species" = species of measurement "_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 "HQS" = Threshold value "HQSdiff" = difference between clLY and HQS "HQSbelow" = whether the mean value in the last monitoring year is significantly below HQS

This dataset represents the underlying sediment data on core indicator TBT and imposex. The core indicator evaluates the status of the marine environment based on concentrations of the tributyltin (TBT) and its breakdown products dibutyltin (DBT) and monobutyltin (MBT) in the Baltic Sea; in water, biota (mussels, marine gastropods) and sediments. Imposex effects of TBT on marine gastropods are used as another source of data on TBT. Quantitative thresholds are used to evaluate if core indicators status is Achieve, Fail or Not assessed. Good status is achieved when the concentrations of TBT 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 region "country" = country "station" = Unique text that identifies the station "stationNam" = name for the station "determinan" = determinant parameter "detGroup" = the grouping of determinands 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 dataset represents the underlying data on core indicator PCB, dioxin and furan. The core indicator evaluates the status of the marine environment based on concentrations of dioxin and dioxin like compounds in Baltic Sea fish, crustacean and molluscs as well as on concentrations of non-dioxin like PCB in Baltic Sea fish. Good status is achieved when the concentrations of PCB, dioxin and furan are below the threshold values. 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 "species" = species of measurement "_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 "HQS" = Threshold value "HQSdiff" = difference between clLY and HQS "HQSbelow" = whether the mean value in the last monitoring year is significantly below HQS

This indicator evaluates the eutrophication status of the Baltic Sea area based on annual total nitrogen concentration. The measured average total nitrogen is derived from in-situ measurements from oceanographic monitoring data for 2011-2016 (µmol/l), surface water (0-10 m). More detailed description on methodology can be found at http://www.helcom.fi/baltic-sea-trends/indicators/total-nitrogen-(tn)/ and http://www.helcom.fi/Documents/Eutrophication%20assessment%20manual.pdf This dataset displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 open sea sub-basins and division of coastal areas to WFD water types or water bodies). The open sea areas have been assessed based on HELCOM Monitoring data and results for coastal areas are based on national WFD results. Some of the open sea areas have not been assessed due to lack of commonly agreed threshold value. Attribute information: “HELCOM_ID” = Code of the HELCOM scale 4 assessment unit "Country" = Country/ Opensea "level_2" = Name of the HELCOM scale 2 assessment unit "Name" = Name of the HELCOM scale 4 assessment unit” "Area (km2)" = Area of the HELCOM scale 2 assessment unit "Indicator" = Name of indicator “Season” = Season of the indicator “Period” = Assessment unit period (20112016 = 2011 – 2016) "Indicator value (ES)" = Indicator value calculated for the assessment unit "Standard deviation (STD)" = Standard deviation of data used for calculating ES "Number of samples " = Number of samples per assessment unit "Thershold value (ET)" = Commonly agreed thershold value "Ratio between ES and ET (ER)" = Ratio between ES and ET (in case of indicator with positive response to eutrophication) "ES_SCORE” = Confidence based on the data used for calculating ES "ET_SCORE” = Confidence of target-setting procedure "I_SCORE” = Confidence (%) = average of ES-Score and ET-Score "Indicator Weight" = Indicator Weight in integrated eutrophication assessment “Status” = Status of the indicator (“Good”, “Not good”, “Not assessed” or "Not applicable") “Confidence” = Confidence of result based on I-SCORE (“High”, “Moderate” or “Low”) "AULEVEL" = Assessment unit level used for the indicator "ET_wint" = Commonly agreed thershold value in winter "ER_winter" = Ratio between ES and ET (in case of indicator with positive response to eutrophication) in winter "Winter status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) in winter

This core indicator evaluates the status of abundance of wintering waterbirds in the Baltic Sea region, here visualized for grazing feeders. The wintering waterbirds are considered to reflect good status when at least 75% of the considered species deviate less than 30% downwards (species laying more than one egg per year) or 20% downwards (species laying one egg per year) from the baseline condition during the reference period 1991-2000. This dataset displays the result of the indicator in HELCOM Assessment Scale 3 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and offshore areas). Attribute information: "HELCOM_ID" = ID of the HELCOM scale 3 assessment unit "country" = Country "Group area" = Name of the group area "level_2" = Name of scale 2 HELCOM assessment unit (subbasin) "level_3" = Name of scale 3 HELCOM assessment unit "Area (km2)" = Area of HELCOM assessment unit "coastal" = HELCOM ID of the coastal areas "open_sea" = Open sea assessment unit name "Abundance" = Assessed parameter "Threshold" = Threshold value "Wading feeders" = Results for the category "Wading feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Surface feeders" = Results for the category "Surface feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Pelagic feeders" = Results for the category "Pelagic feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Benthic feeders" = Results for the category "Benthic feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Grazing feeders" = Results for the category "Grazing feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator

The indicator evaluates the coincidence of seasonal succession of dominating phytoplankton groups over an assessment period (commonly 5-6 years) using regionally established reference seasonal growth curves and wet weight biomass data. The indicator result value is based on the number of data points falling within the acceptable deviation range set for each monthly point of the reference growth curve and expressed as the percentage to the total number of data points. This result value is then compared to regionally relevant threshold values established to represent acceptable levels of variation. Strong deviations from the reference growth curves will result in failure to meet the thresholds set for acceptable variation, indicating impairment of the environmental status and a failure to meet good status. Seasonal succession of dominating phytoplankton groups displays the result of the indicator in HELCOM Assessment Scale 3 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and offshore areas). Attribute information: "HELCOM_ID" = HELCOM ID of the HELCOM scale 3 assessment unit "country" = Country "level_2" = Name of HELCOM scale 2 assessment unit "level_3" = Name of HELCOM scale 3 assessment unit "Area (km2)" = Area of HELCOM assessment unit "Overall Score" = Indicator value or result "Info" = additional info "AULEVEL" = Assessment unit level used for the indicator "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Assessment" = Assessment unit name "Reference period" = Reference period(s) "Threshold value" = Threshold value (overall) "Indicator cyanobacteria" = Indicator value for cyanobacteria "Indicator dinoflagellates" = Indicator value for dinoflagellates "Indicator diatoms" = Indicator value for diatoms "Indicator Mesodinium rubrum" = Indicator value for Mesodinium rubrum "Indicator green algae" = Indicator value for green algae