Data set represents the HELCOM 10x10 km Baltic Sea grid. The grid is based on the European Environment agency (EEA) grid system, and its compatible with other grid sizes. Each grid cell have an unique identifier, that is based on the EEA coding system, where the identifier consists of the cell size and cell coordinates. The grid covers the HELCOM marine area and uses the LAEA projection. HELCOM is making the grid available to offer a standardized and equal area grid system for the Baltic Sea that can be used in different assessments and that is alligned with different grid sizes, such as the "HELCOM 1x1km Baltic Sea grid" or any other EEA based grid system in Europe. The grid is available in two versions: 1. The basic version (HELCOM 10x10km Baltic Sea grid) with full grid cells. This is the version that is visualized in MADS and avaliable for download below as the first link and also as the download link in MADS 2. The second version (HELCOM 10x10km Baltic Sea grid without land areas) where all land areas are removed within the grid cells. This version is not visualized in MADS, but is available for download below. Further details on the 2 different grids can be found in the lineage section below. Attribute information: Unique_ID: Unique ID of the grid cell, based on the EEA coding system Area_km2: Area of the grid cell (for the second version the area is without land areas)

This core indicator evaluates the abundance of selected functional groups of coastal fish in the Baltic Sea. Quantitative thresholds are used to classify core indicators status in "Achieve", "Fail" or "Not assessed". As a rule, good status is achieved when the abundance of piscivores (i.e. fish that feed on other fish) is above a site-specific threshold value, and the abundance of cyprinids or mesopredators (i.e. mid trophic-level fish) is within an acceptable range for the specific site. The status of functional groups of coastal fish in the Baltic Sea has been evaluated by assessing the status of piscivores and cyprinids/mesopredators during the period 2011-2016. This dataset displays the result of the indicator for piscivores 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" = HELCOM ID of the HELCOM scale 3 assessment unit "Country" = Country/ Open sea "level_2" = Name of scale 2 HELCOM assessment unit "Name" = "level_3" = Name of scale 3 HELCOM assessment unit "Area (km2)" = Area of the HELCOM scale 3 assessment unit "Coastal" = Code of scale 3 HELCOM assessment unit  "Open sea" = Name of the open sea area "Coast_Code" = Code of scale 3 HELCOM assessment unit "Subbasin code" = Code of the HELCOM subbasin (scale 3) "Indicator" = Name of the indicator "Unit" = Unit of the indicator "Type" = 1 = boundary values increase/decrease monotonically, 2 = optimum range indicator "Threshold" = Threshold value of indicator "Indicator value" = Result value for the indicator "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator "ConfA" = Confidence of classification "ConfT" = Temporal confidence of classification "ConfS" = Spatial confidence of classification "ConfM" = Methodological confidence of classification

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

Estuaries (according to Habitats Directive Annex I) are coastal inlets that are strongly influenced by freshwater. The distribution map is based on data submission by HELCOM contracting parties. Most of the submitted data is based on modelling, GIS analysis and/or aerial photos. Data coverage, accuracy and the methods in obtaining the data vary between countries.

Input data for the Ecosystem Services Assessment Analytical Module on ReMAP project, created in 2024 and compiled from different data sources is provided. Below is further information on datasets applied for the module and original metadata. More information about the module and the project can be found at http://www.geoportal.ulpgc.es/remap/ Input data contains the benthic habitat distribution originally available at EUSeaMAP (https://emodnet.ec.europa.eu/en/seabed-habitats).

The assessment results for waterbirds for the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3) contains the following datasets: Overall seal integrated result map, Grey seal integrated result map, Ringed seal integrated result map, Harbour seal integrated result map, and Harbour porpoise integrated result map. 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 datasets were created using the BEAT tool. https://github.com/helcomsecretariat/BEAT Attribute information: "Mammals_ag" = Aggregated area "SAULEVEL" = spatial assessment unit ID in which the assessment status took place "ECID" = Ecosystem component ID "EClevel" = Ecosystem Component level "EcosystemComponent" = Ecosystem component assessed "BQR" = Biological Quality Ratio "Conf" = Confidence of the assessment (0-1, higher values mean higher confidence) "ConfClass" = Confidence class

Input of heat pressure dataset contains delta heat values from warm water discharge of - Discharge of warm water from nuclear power plants - Fossil fuel energy production. Discharge of warm water from nuclear power plants (2016-2021): 1 km buffer with steep decrease around outlet (Type D decline), composed of 4 rings [1]. Average input of heat load (Twh) of discharge of warm water from the nuclear power plant outlets. No data on heat load was available for the Leningrad nuclear power plant; therefore, the average heat load of discharge of warm water from nuclear power plants was given. Fossil fuel energy production (only location available): 1 km buffer with steep decrease around outlet (Type D decline), composed of 6 rings[12]. Heat load 1 (TWh) was given to all production sites, based on the average heat load of an individual production site in Helsinki. Heat load from both layers were summed and the layer was normalized. [1] Extent based on Ilus et al. 1986.

This dataset represents the underlying data on core indicator in Abundance of key coastal fish species. The core indicator evaluates the abundance of typical species of fish, such as perch and flounder, in the coastal areas of the Baltic Sea, to assess environmental status. Quantitative thresholds are used to evaluate if core indicators status is Good, Not good or Not assessed. As a rule, good status is achieved when the abundance is above a set site and species-specific threshold value. 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: "COUNTRY" = Country code "DATAPROVID" = Data provider "AREANAME" = ICES area "A_unit" = Name of scale 3 HELCOM assessment unit "IND_VALUE" = Result value for the indicator "METHOD" = Catch method "GEARTYPE" = Gear type of catch "SEASONID" = Season

The layer depicts the pressure of eutrophication in the Baltic Sea, based on the data from the HOLAS 3 integrated eutrophication assessment. The methodology utilizes the Eutrophication Quality Ratios (EQRS) available for each HELCOM assessment unit on level 4b. The results of integrated eutrophication assessment combines the information of the three MSFD criteria groups (C1: Nutrient levels, C2: Direct effect, C3: Indirect effect) and use this value as an indication of pressure for each assessment unit. The Spatial Impact and Pressure Assessment is carried out using a 1x1km grid while the Integrated eutrophication status is assessed on vector based HELCOM assessment units, the vector data are rasterized. First, the vector data are rasterized to 100x100m resolution, and after that it is aggregated to a 10x10km grid using a mean value. A 10 km grid is used in order to make the gradients between assessment units slightly smoother and finally the values converted to 1x1 km resolution. The scale for the pressure values in the map (0.26-1) represents the scale in the original source data.

The data set is showing protected areas (Ramsar, UNESCO Biosphere Reserves and Natura2000) in the Baltic Sea area as polygons. This dataset is used for the BRISK project (Sub-regional risk of spill of oil and hazardous substances in the Baltic Sea, http://www.brisk.helcom.fi/). The dataset has been produced by COWI (http://www.cowi.dk) based on data collected from HELCOM and Baltic Sea countries (Finland: Copyright SYKE). 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.