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 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 Integrated biodiversity status assessment for seals (grey seal, harbour seal and ringed seal). 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 status of the seals was assessed using four core indicators: population trends and abundance of seals, distribution of Baltic seals, nutritional status of seals, and reproductive status of seals. In the latter two only grey seals are considered for the 2018 State of the Baltic Sea report. The assessment is based on the one-out-all-out approach, i.e. the species reflecting the worst status in each assessment unit. This dataset displays the result of the integrated biodiversity status in HELCOM Assessment unit Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "HELCOM_ID" = ID of the HELCOM scale 2 assessment unit "level_2" = Name of the HELCOM scale 2 assessment unit "EcosystemC" = Ecosystem component analyzed "BQR" = Biological Quality Ratio "Conf" = Confidence of the assessment "Total_indi" = Number of indicators used "% of area assessed" = Share of the total assessed area "D1CX" = MSFD descriptor 1 criteria X "conf_D1CX" = Confidence for MSFD descriptor criteria X "Confidence" = Conifdence of the assessment ("high"/ "moderate"/ "low") "STATUS" = Status of the assessment (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 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 represents the underlying sediment data on core indicator Polyaromatic hydrocarbons (PAH) and their metabolites. The core indicator evaluates the status of the marine environment based on concentrations of Polyaromatic hydrocarbons (PAH) in sediment and biota. Quantitative threshold value is used to evaluate if core indicators status is Achieve, Fail or Not assessed. As There is no commonly agreed threshold value for measuring metabolites available, this report only considers concentrations of contaminants. 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 (ANT = anthracene) "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 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 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 dataset contains pre-core indicator results developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3).

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