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 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

Illegal oil discharges data is based on airborne surveillance supplemented with remote sensing equipment in the Baltic Sea Area carried out by HELCOM Contracting Parties within HELCOM IWGAS group. Aerial surveillance is limited within Russia and Latvia. Attribute information: "HELCOM_ID" = HELCOM ID "Country" = Country of observation "Year" = Year of observation "FlightType" = Flight observation performed at Day or Night "Date" = Date of the observation "Time_UTC" = Time of the observation (time zone is UTC) "Wind_speed" = Wind speed during observation "Wind_direc" = Wind direction during observation "Latitude" = longitude coordinate of observed oil spill "Longitude" = longitude coordinate of observed oil spill "Length__km" = length in km "Width__km_" = Width in km "Area__km2_" = Area in km2 "Spill_cat" = Spill category (oil or orther substance detected) "EstimVol_m" = Estimated volume of oil spill (m3) "Category" = Category of oil spill "SPILL" = Spill ID

This dataset represents the underlying biota data on core indicator Hexabromocyclododecane (HBCDD). The core indicator evaluates the status of the marine environment based on concentrations of Hexabromocyclododecane (HBCDD) in Baltic Sea fish. 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 subbasin "country" = country/ opensea "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter "detGroup" = the grouping of determinants used to display the results "species" = species of measurment "_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 average chlorophyll-a concentration in surface water (0 – 10 m) during summer (June – September) during the assessment period 2011-2016. The measured average chlorophyll-a is a combined estimate of two types of data: 1) in-situ measurements from oceanographic monitoring data (surface water 0-10 m) and 2) earth observation data. More detailed description on methodology can be found at HELCOM Core indicator report 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 earth observation data for year 2011 (ENVISAT/MERIS instrument observations with FUB bio-optical model). Results for coastal areas are based on national WFD results. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "Country" = Country/ Opensea "level_2" = name of the subbasin "level_4" = Name of the HELCOM scale 4 assessment unit "Area (km2)" = Area of the HELCOM scale 4 assessment unit "Indicator" = Name of indicator “Season” = Season of the indicator (Summer = June-September) “Period” = Assessment 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 by assessment unit "Theshold value (ET)" = Commonly agreed thershold value "Ratio between ES and ET (ER)" = Eutrophication ratio: 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

This dataset represents the underlying biota 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 (VDS = Vas deference Sequence) "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 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 contains pre-core indicator results developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3).

This indicator evaluates the eutrophication status of the Baltic Sea area based on annual total phosphorus concentration. The measured average total phosphorus on 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-phosphorus-(tp)/ 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 (Summer = June-September) “Period” = Assessment unit period start and end year (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 "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 "Winter status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) in winter "Winter ratio between ES and ET (ER)" = Ratio between ES and ET (in case of indicator with positive response to eutrophication) in winter "Winter indicator value (ES)" = Commonly agreed thershold value in winter

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)