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.

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).

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.

Observations of Fucus serratus 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. Fucus serratus 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: 0 = no observations 1 = present before year 1995 or in 1995 2 = present after year 1995 3 = present before and after year 1995

This dataset contains all HBCD stations by sub-basin in the Baltic Sea as reported to the HELCOM MORE project.

The maps are the result of a compilation of the data submitted by HELCOM contracting parties to the data call for HOLAS 3. Most of the submitted data is based on modeling, GIS analysis, and only limited ground-truthing has been carried out. Original vector data was transformed to 1x1km grid raster. Data coverage, accuracy and the methods of obtaining the data vary between countries. Data were reported by Denmark, Germany, Estonia and Finland. The dataset contains the compilation of the EU Habitat Directive marine habitat types in the Baltic Sea: - Sandbanks (1110) - Estuaries (1130) - Mudflats and sandflats (1140) - Coastal lagoons (1150) - Large shallow inlets and bays (1160) - Reefs (1170) - Baltic Esker islands (1610) - Submarine structures made by leaking gas (1180) - Boreal Baltic islets and small islands (1620)

This dataset contains the most up-to-date reported data about hydrographical monitoring stations in the Baltic Sea. Dataset for download contains Baltic Sea hydrographical monitoring stations. Frequency can be found in corresponding name column.

This dataset contains coastal fish key species and key functional group indicator data collected from national coastal fish monitoring programs as coordinated under HELCOM FISH PRO, FISH PRO II, FISH PRO III and EG Coastal Fish and used for HELCOM coastal fish indicator and thematic assessments. HELCOM Coastal fish core indicator database (COOL) contains updated data used in coastal fish core indicators for every current monitoring station in the Baltic Sea and information on the latest status assessment for the two coastal fish indicators: https://indicators.helcom.fi/indicator/coastal-fish-key-groups/ https://indicators.helcom.fi/indicator/coastal-fish-key-species/ The collection of monitoring data is described in the Monitoring guideline: https://helcom.fi/wp-content/uploads/2020/01/HELCOM-Guidelines-for-coastal-fish-monitoring-2019.pdf The database was originally developed in BalticBoost project (https://helcom.fi/helcom-at-work/projects/balticboost/) Theme 1: Biodiversity, which focused on creating a biodiversity assessment tool and improving data arrangements for the biodiversity elements where this is limited (e.g. coastal fish, birds and seals) so that a comprehensive assessment of biodiversity in the Baltic Sea can be carried out by 2018. The dataset is divided to pointwise observations where values are collected from one single location and polygon areas where values reflect larger area (ICES squares). The data is reported by national representatives of HELCOM EG Coastal Fish and validated annually in the group meeting and hosted by HELCOM Secretariat. Attributes: ID = Unique identifier of observation Country = Country of organization carrying out monitoring (in ISO 2-digit country codes) Organization = Organization carrying out monitoring AreaID = ID of monitoring areas AreaName = Name of monitored area Latitude = Latitude coordinate of monitoring site in WGS84 decimal degrees Longitude = Longitude coordinate of monitoring site in WGS84 decimal degrees L3_AssessmentUnit = HELCOM Level3 assessment unit Year = Year of observation IndicatorName = Indicator which the obsrevation value is related to IndicatorValue = Indicator value as in CPUE/WPUE Species = Key coastal fish species tthat indicator value applies to FunctionalGroup = Key coastal fish functional group that indicator value applies to Method = Monitoring method Geartype = Gear type used for monitoring Season = Season of monitoring RegistrationDate = Date when observation was included in the Coastal fish database