This dataset contains datasets for the Eutrophication assessment developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3). The dataset contains all Baltic Sea monitoring CTD data reported by HELCOM Contracting Parties to ICES for the HOLAS3 assessment period 2016-2021. The data have been reported using the ICES Ocean reporting format: https://www.ices.dk/data/data-portals/Pages/ocean-format.aspx https://www.ices.dk/data/Documents/ocean/ICES-Oceanography-Data-Submission-Format.zip

Springtime Chl-a concentration is here used as a proxy for productive surface waters. In the Baltic Sea Spatial Pressure and Impact Index (SPIA), areas with high springtime phytoplankton production will be given higher importance, as they are considered important areas for the Baltic Sea food web. In the current map, mean of springtime maximum weekly values (weeks 12-22 for the HOLAS3 assessment period 2016-2021). Satellite Chl-a concentration of the surface waters has been used and converted to index by Finnish Environment institute with resolution of 1 km x 1 km grid cells.

This dataset represents the underlying biota data on core indicator Polybrominated diphenyl ethers (PBDE) .The core indicator evaluates the status of the marine environment based on concentrations of Polybrominated diphenyl ethers (PBDE) in biota and sediment. Quantitative thresholds are used to evaluate if core indicators status is Achieve, Fail or Not assessed. 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/ opensea "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 "colou"r = 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 core indicator evaluates the status of abundance of breeding waterbirds in the Baltic Sea region. The breeding 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 1 (Whole Baltic Sea). Attribute information: "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator "level_1" = Name of HELCOM scale 1 assessment unit "Common Shelduck" = Results for common shelduck "Eurasian Oystercatcher" = Results for Eurasian oystercatcher "Pied Avocet" = Results for pied avocet "Ringed Plover" = Results for ringed plover "Turnstone" = Results for turnstone "Dunlin" = Results for dunlin "Arctic Skua" = Results for Arctic skua "Common Gull" = Results for common gull "Herrin Gull" = Results for herring gull "Lesser black-backed gull" = Results for lesser black-backed gull "Little Tern" = Results for little tern "Caspian Tern" = Results for Caspian tern "Arctic Tern" = Results for Arctic tern "Goosander" = Results for goosander "Red-breasted Merganser" = Results for red-breasted merganser "Great crested grebe" = Results for great crested grebe "Great Cormorant" = Results for great cormorant "Razorbill" = Results for razorbill "Common Guillemot" = Results for common guillemot "Black Guillemot" = Results for black guillemot "Tufted Duck" = Results for tufted duck "Common Eider" = Results for common eider "Velvet Scoter" = Results for velvet scoter "Mute Swan" = Results for mute swan "Graylag Goose" = Results for greylag goose "Great black-backed Gull" = Results for great black-backed gull "Sandwich Tern" = Results for sandwich tern "Greater Scaup" = Results for greater scaup

This dataset represents the underlying biota data on core indicator Heavy metals – Mercury.The core indicator evaluates the status of the marine environment based on concentrations of heavy metal Mercury (Hg) in fish muscle. Quantitative threshold value is 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 subbasin "country" = country "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter (HG = Mercury) "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 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 core indicator evaluates the status of abundance of wintering waterbirds in the Baltic Sea region, here visualized for benthic 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

This core indicator evaluates the status of the Baltic Sea based on the number- and the size of illegal oil spills detected in annual aerial surveillance. Quantitative thresholds are used to evaluate if core indicators status is "Achieve", "Fail" or "Not assessed". Good status is achieved when the amount of oil spills are below the threshold value. This 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" = Code of the HELCOM scale 2 assessment unit "level_2" = name of he HELCOM scale 2 assessment unit (subbasin) "Area (km2)" = Area of the HELCOM scale 2 assessment unit "AULEVEL" = Assessment unit level used for the indicator "STATUS" = Status of the indicator (“Target achieved”, “Target exceeded” or “Not assessed”)

This core indicator evaluates the eutrophication status of the Baltic Sea area based on oxygen debt. The oxygen debt value is calculated based on data reported to HELCOM COMBINE database using script developed in TARGREV project and further developed within EUTRO OPER project. The R-script for calculating oxygen is accessible from https://github.com/ices-tools-prod/HEAT/tree/master/scripts/OxygenDebt 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), but applicable only to certain open sea assessment units. Coastal areas were excluded from the shapefile. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "Country" = country/ opensea "level_2" = name of subbasin "level_4" = Name of the HELCOM scale 4 assessment unit "Area (km2)" = Area of the HELCOM scale 2 assessment unit “Name_1” = "Name" = Name of the open sea area “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 in 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 (“Achieve”, “Fail”, “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

This dataset contains integrated eutrophication status assessment 2011-2016. The assessment is done using the HEAT 3.0 by combining assessment unit-specific results from various indicators by three MSFD criteria groups (C1: Nutrient levels, C2: Direct effect, C3: Indirect effect). The assessment is done on HELCOM Assessment Unit level 4: HELCOM Subbasins with coastal WFD water type or water bodies. The HEAT 3.0 has been applied for open sea assessment units using HELCOM core indicators and for coastal areas using national WFD indicators. In case of Denmark, the WFD results were used directly, displaying different classification as obtained from HEAT. For more information about the methodology, see the State of the Baltic Sea report and HELCOM Eutrophication assessment manual. Attribute information: "HELCOM_ID": ID of the HELCOM Level 4 Assessment unit "Country": Country/ Opensea "level_2": Name of the HELCOM Level 2 Assessment unit "Name": Name of the HELCOM Level 4 Assessment unit "Area_km2": Area of assessment unit "C1_N": MSFD criteria 1, number of indicators used for calculating Eutrophication Ratio (ER) "C1_ER": MSFD Criteria 1, ER "C1_SCORE": MSFD Criteria 1, Confidence of ER "C2_N": MSFD Criteria 2, number of indicators used for calculating ER "C2_ER": MSFD Criteria 2, ER "C2_SCORE": MSFD Criteria 2, Confidence of ER "C3_N": MSFD Criteria 3, number of indicators used for calculating ER "C3_ER": MSFD Criteria 3, ER "C3_SCORE": Criteria 3, Confidence of ER "N": Number of criteria used for calculating overall ER "ER": Overall ER "SCORE": Status confidence "STATUS": Status classification (Good (classes 0-0.5 & 0.5-1.0), Not Good (classes 1.0-1.5, 1.5-2.0 & >2.0), Not assessed) "CONFIDENCE": Final confidence class (< 50% = low, 50-74 % = Moderate, = 75 % = High) "AULEVEL": Level of assessment units