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).

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 is a dataset of designated places of refuge reported by HELCOM member countries by year 2011.

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

The dataset contains the number of hunted birds (number of birds/area) per year per area for each target species: common scooter (Melanitta nigra), velvet scoter (Melanitta fusca), eider (Somateri molissima) and long tailed duck (Clangula hymalis). The dataset covers the period 2016-2021. The data was made available by HELCOM Contracting Parties in response to a data call. The data was reported by Denmark, Estonia, Finland and Sweden. The activity was declared as not relevant in Germany, Latvia and Poland. Attribute specification and units: Area: Name of the area given by the national data provider Eid_2016-Eid_2021: Number of hunted eiders in 2016-2021 LTD_2016-LTD_201: Number of hunted long tailed ducks in 2016-2021 Sco_2016-Sco_2021: Number of hunted common scoters in 2016-2021 VSc_2016-VSc_2021: Number of hunted velvet scoters in 2016-2021 avg_syears: average of number of hunted birds

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

A vector grid in 2 x 2 km resolution showing model results of environmental impact caused by spill of soluble oil from ships with size greater than 5000 t as as g oil / km^2 weighted.This dataset has been produced by COWI (http://www.cowi.dk) for the BRISK project (Sub-regional risk of spill of oil and hazardous substances in the Baltic Sea, http://www.brisk.helcom.fi/). Fields: COL_NO (Dbl): Column ROW_NO (Dbl): Row WLoad (Dbl): Environmental impact (g oil / km^2 weighted).