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 indicator evaluates the eutrophication status of the Baltic Sea area based on dissolved inorganic phosphorus (DIP) concentration. The measured average DIP is based on in-situ PO4 measurements from oceanographic monitoring data for winter period (December-February) 2011-2016 (umol/l), surface water (0-10 m). More detailed description on methodology can be found at http://www.helcom.fi/baltic-sea-trends/indicators/Dissolved-inorganic-phosphorus-(DIP) 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. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "Country" = country "level_2" = name of subbasin "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 (Winter = December-February) “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”, “Low” or "Not assessed") "AULEVEL" = Assessment unit level used for the indicator

This dataset represents the underlying data on core indicator Abundance of waterbirds in the wintering season 2018. Attribute information: "SITECODE_n" =unique site code "YEAR" = year of the observation "SPECIES" = species observed "ABUNDANCE" = Abundance "Country" = Country code "COORD_ X": longitude coordinate of site "COORD_Y": latitude coordinate of station "SITECODE": unique site code with country code

This dataset represents the underlying data on core indicator 'Reproductive disorders: malformed embryos of amphipods 2018'. The core indicator evaluates the status of the marine environment based on the presence of hazardous substances in the bottom sediments. The rate of embryo malformations indicates reproductive toxicity due to the presence of hazardous substances in the bottom sediments. The threshold value has not been achieved on all stations within each basin indicating that toxic effects of contaminants may be present. The variability of the malformation rate is much greater within a basin than between the Bothnian Sea and the Baltic proper. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "YEAR" = Year of sampling "Basin" = Subbasin abbreviation "REGION" = Region code within the Baltic Sea "STATN" = Station "Lat_WGS84d" = latitude coordinate of station "Lon_WGS84d" = longitude coordinate of station "TotalEmbry" = Total embryos "UNDIFFiren" = Undifferentiated "MALFORmed" = Malformed "MEMBraneDa" = Membrane damage "FemalesWME" = Females with malformed embryos "NofFemales" = Number of Females "AveFecundi" = Average Fecundity "STN" = "FFemWAE" = Frequency Females with aberrated embryos "FreqAberrE" = Frequency Aberrant Embryos "inGES_Fem" = inGES (Females) "inGES_Emb" = inGES (Embryos) "inGES_Over" = inGES (overall)

This dataset contains integrated eutrophication status assessment 2011-2016, visualized for nutrient levels (C1_ER). 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. For more information about the methodology, see State of the Baltic Sea report and HELCOM Eutrophication assessment manual. Attribute information: "HELCOM_ID": ID of HELCOM Level 4 Assessment unit "Country": Country/ open sea "level_2": Name of HELCOM Level 2 Assessment unit "Name": Name of HELCOM Level 4 Assessment unit "Area_km2": Area of assessment unit "C1_N": Criteria 1, number of indicators used for calculating Eutrophication Ratio (ER) "C1_ER": Criteria 1, ER "C1_SCORE": Criteria 1, Confidence of ER "C2_N": Criteria 2, number of indicators used for calculating ER "C2_ER": Criteria 2, ER "C2_SCORE": Criteria 2, Confidence of ER "C3_N": Criteria 3, number of indicators used for calculating ER "C3_ER": 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 rating (< 50% = low, 50-74 % = Moderate, = 75 % = High) "AULEVEL": Level of assessment units

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 dataset contains pre-core indicator data developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3).

Summary Light availability in the Baltic Sea. The Baltic Sea bottom is divided into photic (1) and non-photic (2) bottoms. Description The dataset contains information on light availability in the Baltic Sea. The Baltic Sea bottom is divided into photic (1) and non-photic (2) bottoms (areas where 1% of available light reaches the seabed). The light availability data has been produced withing the EUSeaMap project and was reported on request to HELCOM Secretariat by DHI.

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