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

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 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 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))

The Diatom/Dinoflagellate index (Dia/Dino index) reflects the dominance patterns in the phytoplankton spring bloom. It has high relevance for the pathway of the food into the pelagic or benthic food web. In principle, the indicator is applicable in all coastal and open sea assessment units, except lagoons, large river plumes and the Bothnian Bay; however, thresholds for the good status are defined only for the southern and central Baltic Sea up to now. The indicator is not yet agreed as a HELCOM core indicator but is tested in the HOLAS II project for the Eastern Gotland Basin. In this assessment unit, the average Dia/Dino index of the years 2011-2016 was just below the threshold value of 0.5 for good status. The confidence of the indicator evaluation depends on the data frequency. The data have to represent the diatom and dinoflagellate blooms adequately. If the diatom bloom is not sufficiently represented in the data, an alternative Dia/Dino index may be applied, based on silicate consumption data. This indicator is robust; its calculation is simple and traceable. The phytoplankton monitoring is operational in the whole Baltic Sea using methods prescribed in the COMBINE manual. Currently, a high quality of the data is assured by the experts of the HELCOM Phytoplankton Expert Group (PEG). The basic data are phytoplankton biomass data, determined as explained in the HELCOM COMBINE manual, originating from the depth of 0 – 10 m. Also silicate data were used that were taken parallel to the phytoplankton sampling. Diatom-dinoflagellate ratio 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" = ID of the HELCOM scale 2 assessment unit "Area (km2)" = Area of the HELCOM assessment unit "Name" = Name of the HELCOM scale 2 assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Threshold value" = Threshold value of indicator "Unit" = Unit of the indicator "Indicator value" = Result of the indicator "AULEVEL" = Assessment unit level used for the indicator

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 core indicator evaluates the status of the white-tailed eagle by assessing breeding success, brood size and productivity. Quantitative thresholds are used to evaluate if core indicator Achieves or Fails Good status or if the status is Not assessed. Note that in some areas the indicator is applicable but not assessed, while it is not applicable in others. 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" = Code of the HELCOM scale 3 assessment unit "Country" = country/ opensea "Area (km2) = Area of HELCOM assessment unit "level_3" = Code of scale 3 HELCOM assessment unit "AULEVEL" = Assessment unit level used for the indicator "Area" = description of the assessment unit "Breeding Success" = Results for Breeding Success "Breeding Success Status" = Status of the indicator for Breeding Success ("GES" = Good Environmental Status, "subGES" = Good Environmental status not achieved, applicable, not applicable) "BroodSize" = Results for Brood Size "Brood Size Status" = Status of the indicator for Brood Size ("GES" = Good Environmental Status, "subGES" = Good Environmental status not achieved, applicable, not applicable) "Productivity" = Results for Productivity "Productivity Status" = Status of the indicator for Productivity ("GES" = Good Environmental Status, "subGES" = Good Environmental status not achieved, applicable, not applicable) "Overall status" = Overall Status of the indicator according to one-out-all-out (“Achieve”, “Fail”, “Applicable” or “Not applicable”)

This dataset contains integrated eutrophication status assessment 2011-2016, visualized for direct effects (C2_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 / opensea "level_2": Name of HELCOM Level 2 Assessment unit "Name": Name of HELCOM Level 4 Assessment unit "Area_km2": Area of assessment unit Descriptio: Name 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