Introduction of radionuclides is based on HELCOM MORS discharge data (2016-2020) . Annual averages of CO60, CS137 and SR90 from the period 2016-2020 per nuclear power plant. Gradual buffer around outlet to 10km distance (Type B decline). 10 km buffer with linear decline composed of 5 rings from discharges of radioactive substances (Type B decline)12.

Observations of Larus melanocephalus were collected from the Baltic Sea area for HELCOM Red List species list. The HELCOM Red List of Baltic Sea species in danger of becoming extinct (2013) is the first threat assessment for Baltic Sea species that covers all marine mammals, fish, birds, macrophytes (aquatic plants), and benthic invertebrates, and follows the Red List criteria of the International Union for Conservation of Nature (IUCN). Almost 2800 species were considered in the Red List assessment and about 1750 were evaluated according to the IUCN Red List criteria. Larus melanocephalus has been placed to the Red List category of Endangered (EN) species. The map shows the species range only during breeding season.

Summary Estimated observations of the biotope AA.A1H2, AB.A1H2, AA.M1H2 and AB.M1H2 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic or aphotic rock and boulders or mixed substrate dominated by erect moss animals (Flustra foliacea) The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea. Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.A1H2, AB.A1H2, AA.M1H2 andAB.M1H2according to HELCOM RED LIST assessment experts: The Flustra foliacea dominated biotope commonly occurs from Kattegat to the Mecklenburg Bight andArkona Basin (Kadetrinne). The spatial restriction to the Western Baltic Sea is due to the salinityrequirements of the dominant species Flustra foliacea. The more to the west or north-west this biotopeoccurs the higher the salinities, and in consequence the higher the diversity of inhabiting invertebrateand fish communities. The distribution map indicates the area in the 100 x 100 km grid where biotope isknown to occur, the occurrence of the biotope in the photic zone is restricted to the negative surfaces offor example boulders. AA.A1H2, AB.A1H2, AA.M1H2 and AB.M1H2 have been placed in the Red List classification to the category of Near Threatened (NT) biotopes. (Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

This dataset contains all heavy metal monitoring station locations where sediment is samples are analyzed as reported to HELCOM secretariat by HELCOM Contracting Parties by 2016.

This dataset contains data used for the HELCOM Core indicator State of the soft-bottom macrofauna community for HOLAS 3. Attribute information: "SampleID" = Sample ID "Station" = Station name "Year" = Year of sampling event "Latitude" = Latitude coordinate (WGS84 decimal degrees) "Longitude" = Longitude coordinate (WGS84 decimal degrees) "Depth" = Depth of station (m) "Sentivit" = Sensitivity subset "Sampling_a" = Sampling area (cm2) "Sieve_mesh" = Sive mesh size (microm) "BQI" = Benthic quality index value "Data sourc" = Source of data (national monitoring / other) "Data_origi" = Data providing organization "Country" = Data providing country "Assessment" = HELCOM Level 2 assessment unit where the station resides

The dataset contains information on commercial fishery in Baltic Sea in 2007 (Lithuanian data from 2008). Catches/landings are given per ICES rectangle, both as total values and per fishing gear type. The dataset contains information on commercial fishery in Baltic Sea in 2007 (Lithuanian data from 2008). Catches/landings are given per ICES rectangle, both as total values and per fishing gear type. The gear categories are: 0 = unspecified, 1 = surface and mid-water gears, 2 = bottom trawling gears and 3 = coastal and stationary gears. All values are in tons. Data was requested from HELCOM contracting parties through HELCOM HOLAS project. Landings/ catches data from Finland, Sweden, Denmark, Germany, Poland, Lithuania, Latvia and Estonia is based on national data, while Russian data is based on the ICES report "Report of the Baltic Fisheries Assessment Working Group (WGBFAS)" (2008). Commercial fishery data was reported by the following persons/authorities to HELCOM Secretariat: Germany:Dr. Christopher Zimmermann (Institut für Ostseefischerei (OSF), Johann Heinrich von Thünen-Institut (vTI), Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei) Lithuania: Open sea: Irina Jakovleva (Fisheries Reguliation Division, Baltic Sea Fisheries Department, Fisheries Department under the Ministry of Agriculture); coastal: Rimantas Repecka (Head of Laboratory of Marine Ecology, Institute of Ecology of Vilnius University) Sweden: Jarl Engquist (Avdelningen för fiskerikontroll, Swedish Board of Fisheries) Latvia: Marina Fettere (Fishery and Information section, Latvian Fish Resources Agency) Finland: Pirkko Söderkultalahti (Finnish Game and Fisheries Research Institute) Estonia: Ministry of Agriculture Denmark: Troels Pade (The Danish Directorate of Fisheries, Ministry for Food, Agriculture and Fisheries) Russia: no contact person, data from ICES reports Poland: Malgorzata Marciniewicz-Mykieta (Departament Monitoringu i Informacji o Srodowisku, Glówny Inspektorat Ochrony Srodowiska).

Observations of Macroplea mutica were collected from the Baltic Sea area for HELCOM Red List species list. The HELCOM Red List of Baltic Sea species in danger of becoming extinct (2013) is the first threat assessment for Baltic Sea species that covers all marine mammals, fish, birds, macrophytes (aquatic plants), and benthic invertebrates, and follows the Red List criteria of the International Union for Conservation of Nature (IUCN). Almost 2800 species were considered in the Red List assessment and about 1750 were evaluated according to the IUCN Red List criteria. Macroplea mutica has been placed to the Red List category of Least Concern (LC) species. Dataset for download contains spatial grid of the Baltic Sea. Distribution of the species can be found in corresponding name column. Values are coded: 1 - Present before year 2000 or in 2000, 2 - Present after year 2000, 3 - Present both before and after year 2000.

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 herring. Attribute information: "OBJECTID" = Object identification "HELCOM_ID" = Code of the HELCOM scale 2 assessment unit "Indicator" = Name of HELCOM Core indicator "Type" = Type of indicator "Threshold value" = Threshold value for specific assessment unit "Indicator value" = Value of indicator calculated for specific assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”)

This pre-core indicator evaluates the eutrophication status of the Baltic Sea area based on cyanobacterial bloom index. The index is calculated using two types of data: biomass data and Earth observation data. More detailed description on methodology can be found at HELCOM pre-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), but applicable only to certain open sea assessment units. 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 2 assessment unit “Season” = Season of the indicator (Summer = June-September) “Period” = Assessment unit period start and end year (20162021 = 2016 – 2021) "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 (not applicable for cyanobacterial bloom index) "Threshold value (ET)" = Commonly agreed threshold 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") "AULEVEL" = Assessment unit level used for the indicator "FID_12" = "Indicator" = Indicator name “CONFIDENCE” = Confidence of result based on I-SCORE (“High”, “Moderate”, “Low” or "Not assessed")

The data set is showing staging areas for migrating sea and shore birds in the Baltic Sea area as polygons used for the BRISK project (Sub-regional risk of spill of oil and hazardous substances in the Baltic Sea, http://www.brisk.helcom.fi/). This dataset has been produced by COWI (http://www.cowi.dk) based on data collected from Baltic Sea countries (Denmark, Estonia, Finland (Copyright: SYKE), Germany, Latvia, Poland, Russia, Sweden). The dataset includes data provided by the BRISK Project Partner organisations. The detailed documentation of what partner provided what data is given in the Annex of the document: 70618-3.1.2.2 Data Collection Report.