Pressure layer combines all human activities that cause changes to hydrological conditions. The human activities were presented as point data which were given spatial extents (given below). The pressure value was given as the proportion of the grid cell under the pressure. Water course modification: 1 km buffer[10]. Location of water course modifications used for buffer. Overlaps removed and areas of buffer calculated per each grid cell. The final value was the area of the buffer in each individual cell. Wind farms: 300 m buffer around each turbine classified as operational, with linear decline (Type B decline), composed of 3 rings. Location of operational turbines as points were buffered and values given over linear decline. Oil platforms: 500 m buffer around each turbine with linear decline (Type B decline) composed of 5 rings. Location of oil platforms as points were buffered and values given over linear decline. Hydropower dams: A grid cell in the estuary. Locations of hydropower dams were crossed with rivers and the grid cell located in the end of the river was selected as presence (1) – those that are operational and produces energy. Other values in the grid were considered absence. [10] Extent based on wind farms and cables but expanded to 1 km because hydrological parameters are widely spreading. The human activity datasets were first processed separately covering the whole Baltic Sea and then summed together and overlapping areas were dissolved to remove double counting. Attenuation gradients are assigned to each layer as described above. Area effected decreases when distance from avtivity increases. Layer was normalized.

The dataset was created in order to update the information regarding underwater pipelines in the Baltic Sea Region for the HELCOM Assessments. Data was collected by the HELCOM Secretariat during 2015. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Denmark, Germany, Finland and Poland. The report data represents constructions on respective territorial waters, authorized facilities and activities from 2015. The activity was declared as not relevant in Lithuanian area. From Estonia, Latvia, Lithuania, Russia and Sweden no data was reported. Attribute specification and units: NAME COUNTRY CAPACITY (MW) STATUS (Operational, Under Construction, Application Submitted, Planned, Unknown) SOURCE

This dataset represents the underlying data on core indicator Diatom/Dinoflagellate ration 2018. 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: "Station" = Name of station "Date" = Sampling date and time "Assessment" = Name of HELCOM level 2 assessment unit "Biomass_of" = Biomass of all diatoms "Biomass_1" = Biomass of all dinoflagellates (autotrophic and mixotrophic) "Data_origi" = Data originating organization "Use_restri" = Data use restrictions (YES/NO). Restricted data is not included.

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

This core indicator evaluates the state of the marine environment using distribution of the three species of seals that occur in the Baltic Sea. This dataset is for the Ringed seal. Quantitative thresholds are used to evaluate the core indicators status in "Achieve", "Fail" or "Not assessed". The core indicator has three components for each species: distribution of haul-out sites, breeding sites and foraging areas. Good status is achieved when the distribution of seals is close to pristine conditions (e.g. 100 years ago), or where appropriate when currently available haul-out sites are occupied (modern baseline), and when no decrease in area of occupation occurs. The current evaluation covers the assessment period 2011-2016. 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" = ID of the HELCOM scale 2 assessment unit "Area (km2)" = Area of the HELCOM scale 2 assessment unit "Name" = Name of the HELCOM scale 2 assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator

The PLAN BOTHNIA project, co-ordinated by the HELCOM Secretariat, tested transboundary Maritime Spatial Planning in the Baltic Sea. The project used the Bothnian Sea area between Sweden and Finland as a case study of Baltic transboundary MSP. The project was a Baltic Sea MSP “preparatory action” funded by EU Commission DG MARE (budget 0,5 M EUR ) under the EU Integrated Maritime Policy, and run 18 months between 2. December 2010 and 1. June 2012. The final report can be downloaded here: https://planbothnia.org/the-pilot-plan/ The data covers the following topics: Maritime traffic Fishing and aquaculture Energy Nature protected areas Defence Scientific research Sand and gravel Tourism and recreation Cultural heritage All spatial data gathered during the project can be downloaded and used freely given that the source is cited. The data was gathered during the time span of the project (December 2010 and 1. June 2012) and it covers: Maritime traffic Fishing and aquaculture Energy Nature protected areas Defence Scientific research Sand and gravel Tourism and recreation Cultural heritage The source of the data were HELCOM and the different regional councils surrounding the Bothnian Sea.

This dataset represents the underlying sediment data on core indicator Heavy metals – Lead.The core indicator evaluates the status of the marine environment based on concentrations of heavy metal Lead (Pb) in water, fish liver and sediments. Quantitative thresholds are used to evaluate if core indicators status is Achieve, Fail or Not assessed. Threshold values are based on Environmental quality standards (EQS), defined at EU level for substances included in the priority list under the Water Framework Directive. The Core indicator displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and off-shore areas and division of the coastal areas by WFD water types or water bodies). Attribute information: "region" = name of region "country" = country "station" = Unique text that identifies the station "stationNam" = name for the station "determinan" = determinant parameter (PB = Lead) "detGroup" = the grouping of determinands used to display the results "_shape" = shape used to map assessment results "colour" = colour used to map assessment results "l3area" = HELCOM assessment unit on scale 3 "l4area" = HELCOM assessment unit on scale 4 "nyall" = total number of years of data "nyfit" = number of years of data used in the assessment "nypos" = number of years with at least one measurement above the limit of detection "lastyear" = most recent year of data "prtrend" = the significance of the change over the most recent 20 years; for the assessment conducted in November 2017 and published in June 2018, this is the period 1996-2016 "rtrend" = annual ‘linear’ change over the most recent 20 years "meanLY" = fitted value in last monitoring year "clLY" = upper one-sided 95% confidence limit on fitted value in last monitoring year "EQS" = Threshold value "EQSdiff" = difference between clLY and EQS "EQSbelow" = whether the mean value in the last monitoring year is significantly below EQS

This dataset describes fishing intensity for surface mobile bottom contacting gear in 2009 based on VMS/Log book data processed by ICES Working Group on Spatial Fisheries Data (WGSFD). ICES secretariat collected during 2017 relevant VMS and logbook data for 2009-2016 to produce, as a technical service to HELCOM, updated spatial data layers on fishing intensity/pressure. Improved data quality control checks were implemented. Submitted data across the HELCOM area have improved in quality compared to previous data 2009-2013 published in 2015. Standardized methods were used to produce the requested data layers. The code used to create the data products is available here: https://github.com/ices-eg/wg_WGSFD For further technical information on the advice request, see http://www.ices.dk/sites/pub/Publication%20Reports/Advice/2017/Special_requests/helcom.2017.18.pdf HELCOM secretariat did the following processing to the shapefile provided by ICES: - Conversion to ETRS89LAEA coordinate system - Added feature and attribute "Reported" to display unreported areas. Dataset attribute information: c-square: Unique reference of the c-square polygon Year: Year of fishing activity mid_lat: latitude coordinate of the centroid of c-square inWGS84 decimal degrees mid_lon: longitude coordinate of the centroid of c-square inWGS84 decimal degrees SurfaceSAR: Surface area ratio (Swept area, < 2 cm penetration depth of the gear components) Subsurface: Subsurface area ratio (Swept area, subsurface =>2 cm penetration depth of the gear components) totweight: Total Weight (kg) totvalue: Total value (Euros) Kw Fishing Hours: (Kw*h) Fishing hours: (h) Reported: Yes=Reported data. No= No reported data (area that does not contain effort/intensity value due to lack of reported data). Please note that this dataset was updated (v2) in January 2019, see further details below in the lineage section.

Input data for the Cumulative Effects 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/ The Cumulative Effects Assessment Module primarily aims to evaluate the cumulative burden that multiple and simultaneous activities may impose on the marine environment. The analysis utilizes the SPIA tool, applied in HOLAS3 (https://helcom.fi/wp-content/uploads/2023/03/HELCOM-Thematic-assessment-of-spatial-distribution-of-pressures-and-impacts-2016-2021.pdf). MSP data used in the analysis for the Baltic Sea can be found at: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/7e216ec3-25d4-4a4e-89ec-62aceb16eed0 Data used for the ecosystem components at the Baltic Sea can be found at: - Herring and Sprat abundance: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/27cb947f-7b2a-4baa-8eea-e270765e9039 - Cod abundance: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/82c117ab-1a47-4d1e-99cf-5340339fa222 - Bottom habitats not influenced by permanent anoxia: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/5490da33-8df5-4280-a980-e939a589dc8b - Natura habitats: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/cc77dbd9-b4bc-43bf-accf-39fe603c1fda - Seals distribution: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/37ab54cc-1084-4bcd-a76d-2c2738491081 - Wintering and breeding area for birds: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/056d0fe1-d196-4753-834d-3ccbd0c4de51 - Harbour porpoise importance map: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/cb250787-ae97-4452-9caa-eba9abe0ec4e - Benthic species: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/0e879921-850a-4fd4-894f-90ce568a2b66 - Broadscale habitats: https://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/f0770ea9-8110-4145-b85f-afee46d5df85

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