The dataset contains the extraction of one of the target species, cod, for the period 2016-2021. The extraction of cod data set is based on "Fish extraction - commercial fisheries HOLAS 3". Further information about how this dataset was collected and extracted can be found at: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/a0104cfd-d237-459b-84f8-8e9e21d2df9b Reported per ICES Rectangles, Russian data extracted from ICES annual reports, reported per ICES sub-divisions. Values are redistributed with fishing effort data c-squares (all gears) 2016-2021. Effort values missing from Russia and sub-basin average values given. Extraction of fish species (landings) per ICES c-squares, average of 2016-2020. Landings calculated per km2. Tons/km2 calculated for each species. For cod, recreational fisheries catches were added. Log-transformed and normalized.

The dataset reflects the spatial delineation of river catchments in the Baltic Sea drainage area. The data is based on the reporting by Contracting Parties within in the HELCOM Pollution Load Compilation (PLC) framework. The catchments consist of monitored river catchments and unmonitored coastal areas. The delineation of the catchments can be connected to the flow and nitrogen and phosphorous load information available in the PLC assessment data set (https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/441f878f-67e7-4aa8-927e-8f5e073dc893). The river catchments consist of whole rivers, meaning that although a river would run through several countries or would be a border river between two countries, the catchment is not split into separate sub-catchments. The unmonitored areas are aggregated based on PLC subbasins and country areas, thus forming areas such as the unmonitored area of Finnish Gulf of Finland, Polish Baltic Proper or Danish Kattegat. Attribute information: SourceCode: Unique code for river catchment Name: Name of river catchment SubBasin: The PLC subbasin where the river meets the sea. Country: The Country on which territory the river mouth is located, for border rivers both are mentioned. Monitoring: The monitoring status of the river (M=monitored and U=unmonitored). Marked as monitored only if it’s been monitored for the whole time series. Transbound: Listing all countries that have the rivers drainage area on its territory. Area_km2: The total area of the catchment in square kilometers. flow_1995...flow_2022: The water flow of the river catchment for the whole time-series TN_1995...TN_2022: Total nitrogen load of the river catchment for the whole time-series TP_1995...TP_2022: Total phosphorus load of the river catchment for the whole time-series

This dataset contains results on HELCOM Assessment unit level 4b for shallow water oxygen. The information provided represents the data and results from the HELCOM HOLAS 3 indicator evaluation for eutrophication, covering the data period from 2016-2021. Shallow Water Oxygen results are reported by Contracting Parties based on data collected on national level by the Contracting Parties applying the indicator. Coastal assessment units (WFD water types or water bodies) are assessed based on WFD result data reported by countries. Indicator analysis of both open sea and coastal areas is carried out using the HEAT assessment tool (https://github.com/ices-tools-prod/HEAT). This analysis provide the basis of the HELCOM indicator evaluations and are utilized in the HOLAS 3 thematic assessment of eutrophication. Attribute description: ES = Eutrophication Status ES_SD = Standard Deviation ES_N = Number of Observations ES_N_Min = Minimum Number of Observations any given year ES_SE = Standards Error ES_CI = Confidence Interval ET = Eutrophication Target / Threshold ER = Eutrophication Ratio ACDEV = Acceptable Deviation BEST = ET / (1 + ACDEV / 100) EQR = Ecological Quality Ratio EQR_HG = Ecological Quality Ratio High/Good Boundary EQR_GM = Ecological Quality Ratio Good/Moderate Boundary EQR_MP = Ecological Quality Ratio Moderate/Poor Boundary EQR_PB = Ecological Quality Ratio Poor/Bad Boundary EQRS = Ecological Quality Ratio Scaled GTC = General Temporal Confidence STC = Specific Temporal Confindence TTC = Total Temporal Confidence GSC = General Spatial Confidence SSC = Specific Spatial Confidence TSC = Total Spatial Confidence TC = Total Confidence

Potential cumulative impacts of eutrophication and hazardous substances assesses the cumulative potential effect of eutrophication and hazardous substances over all ecosystem components. The evaluation is based on the pressure layer on eutrophication and hazardous substances, combined with information on all ecosystem components (57 layers) included in SPIA for HOLAS 3. The thematic analyses is calculated for each assessment unit (1 km2 grid cells) and the data set covers the time period 2016-2021. Spatial Pressure and Impact Assessment (SPIA) is the framework for assessing spatial and cumulative pressures and impacts in HOLAS 3, and this analyses present a thematic assessment including only a certain subset of layers. The framework also includes results for the Baltic Sea Impact Index (full cumulative impact assessment), Baltic Sea Pressure Index (full cumulative pressure assessment), and other thematic assessments where a subset of pressure and ecosystem layers are used. For more info please - visit the HOLAS 3 website (http://stateofthebalticsea.helcom.fi/) - download the report thematic assessment of spatial distribution of pressures and impacts 2016-2021 (https://helcom.fi/post_type_publ/holas3_spa) - or check out the HELCOM SPIA online tool to make calculations for any desired combination of pressures and ecosystem layers (https://maps.helcom.fi/website/bsii/). Please scroll down to "Lineage" for a more detailed description of the methodology.

This dataset represents the underlying data on core indicator Seasonal succession of dominating phytoplankton groups for HOLAS 3. The core indicator evaluates phytoplankton community structure to determine whether it reflects good environmental status. Quantitative thresholds are used to evaluate if core indicators status is Good, Not good or Not assessed. Attribute information: "Code"= ID of HELCOM level 2 assessment unit "Assessment" = Name of HELCOM level 2 assessment unit "Station" = Name of station "Lat" = Latitude of station in WGS 84 decimal degrees "Lon" = Longitude of station in WGS 84 decimal degrees "Data_avail" = Data availability period (years) "Reference" = Reference period (years) "Data_provi" = Data provider organisation "Country" = Data provider country "Station_na" = Station name "Date" = Sampling date and time "Year" = Year of sampling "Month" = Month of sampling "Cyano" = Cyanobacteria "Dino" = Dinoflagellates "Diatoms" = Diatoms "Meso_rub" = Mesodinium rubrum "CyanoIn" = "DinoIn" = "DiatomsIn" = "MesoRubIn" =

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.

This dataset contains core indicator "TBT and imposex - TBSN in sediment" results developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3). Attribute specifications and units: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "country": country in which the HELCOM assessment unit is located or a mention to an open sea area "level_2" = Name of the HELCOM assessment unit in scale 2 "Name" = Name of the HELCOM assessment unit in scale 4 "Open_sea" = Name of the HELCOM assessment unit in the open sea "F2_Name" = Name of the HELCOM assessment unit "determinan" = Determinat "est" = The estimated mean loge concentration in the assessment unit "se" = The standard error on the estimated mean log concentration in the assessment unit "fit" = The estimated mean concentration in the assessment unit "upper_cl" = Upper one-sided 95% confidence limit on the mean concentration: exp(est + qnorm(0.95) * see) "Status" = Overall Status of the indicator according to one-out-all-out

This core indicator evaluates the status of the marine environment based on concentrations of Polybrominated diphenyl ethers PBDE in biota. Quantitative threshold value is used to classify core indicators status in “Achieve”, “Fail” or “Not assessed”.  Attribute specifications and units: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "country": country in which the HELCOM assessment unit is located or a mention to an open sea area "level_2" = Name of the HELCOM assessment unit in scale 2 "Name" = Name of the HELCOM assessment unit in scale 4 "Open_sea" = Name of the HELCOM assessment unit in the open sea "F2_Name" = Name of the HELCOM assessment unit "determinan" = Determinat "est" = The estimated mean loge concentration in the assessment unit "se" = The standard error on the estimated mean log concentration in the assessment unit "fit" = The estimated mean concentration in the assessment unit "upper_cl" = Upper one-sided 95% confidence limit on the mean concentration: exp(est + qnorm(0.95) * see) "Status" = Overall Status of the indicator according to one-out-all-out

This dataset contains core indicator data developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3).

This dataset contains core indicator "TBT and imposex - TBSN in water" results developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3). Attribute specifications and units: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "country": country in which the HELCOM assessment unit is located or a mention to an open sea area "level_2" = Name of the HELCOM assessment unit in scale 2 "Name" = Name of the HELCOM assessment unit in scale 4 "Open_sea" = Name of the HELCOM assessment unit in the open sea "F2_Name" = Name of the HELCOM assessment unit "determinan" = Determinat "est" = The estimated mean loge concentration in the assessment unit "se" = The standard error on the estimated mean log concentration in the assessment unit "fit" = The estimated mean concentration in the assessment unit "upper_cl" = Upper one-sided 95% confidence limit on the mean concentration: exp(est + qnorm(0.95) * see) "Status" = Overall Status of the indicator according to one-out-all-out