The data set is showing wintering areas for 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 HELCOM, Finland (Copyright: SYKE), Latvia, Lithuania, Poland, Russia and 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.

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. The following human activities were combined into the changes to hydrological conditions layer; - Hydropower dams (a 1km2 grid cell in the river estuary was selected) - Water course modification (1 km) - Wind turbines (operational, 0.3 km, linear decline) - Oil platforms (0.5 km, linear decline) 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 contains the location of fossil fuel energy production facilities derived from the European Pollutant Release and Transfer Register (E-PRTR). E-PRTR cover all HELCOM Contracting Parties except Russia. Attribute specification and units: See E-PRTR code lists at https://www.eionet.europa.eu/schemas/eprtr/listOfValues In the HELCOM data review process, some facility locations appeared to be spatially slightly misplaced, adding up to uncertainty of data products derived from this dataset.

The dataset contains point data describing the location of oil platforms in the Baltic Sea as reported by the Contracting Parties for the period 2016-2021. The data was made available by HELCOM Contracting Parties in response to a data call. The data was reported by Poland (HOLAS 2 data) and Russia. The activity was declared as not relevant by Estonia, Denmark and Latvia. Attribute specification and units: COUNTRY: The country where the structure is located LATITUDE: Latitude of the point location LONGITUDE: Longitude of the point location Name: Name of the structure Notes: Notes regarding the data

This dataset represents the underlying data on core indicator Seasonal succession of dominating phytoplankton groups 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: "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" =

The indicator evaluates the coincidence of seasonal succession of dominating phytoplankton groups over an assessment period (commonly 5-6 years) using regionally established reference seasonal growth curves and wet weight biomass data. The indicator result value is based on the number of data points falling within the acceptable deviation range set for each monthly point of the reference growth curve and expressed as the percentage to the total number of data points. This result value is then compared to regionally relevant threshold values established to represent acceptable levels of variation. Strong deviations from the reference growth curves will result in failure to meet the thresholds set for acceptable variation, indicating impairment of the environmental status and a failure to meet good status. Seasonal succession of dominating phytoplankton groups 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: "HELCOM_ID" = HELCOM ID of the HELCOM scale 3 assessment unit "country" = Country "level_2" = Name of HELCOM scale 2 assessment unit "level_3" = Name of HELCOM scale 3 assessment unit "Area (km2)" = Area of HELCOM assessment unit "Overall Score" = Indicator value or result "Info" = additional info "AULEVEL" = Assessment unit level used for the indicator "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Assessment" = Assessment unit name "Reference period" = Reference period(s) "Threshold value" = Threshold value (overall) "Indicator cyanobacteria" = Indicator value for cyanobacteria "Indicator dinoflagellates" = Indicator value for dinoflagellates "Indicator diatoms" = Indicator value for diatoms "Indicator Mesodinium rubrum" = Indicator value for Mesodinium rubrum "Indicator green algae" = Indicator value for green algae

This dataset describes fishing intensity for OT DMF mobile bottom contacting gear in 2013 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.

This dataset represents the underlying sediment data on core indicator Heavy metals – Cadmium. The core indicator evaluates the status of the marine environment based on concentrations of heavy metal cadmium (Cd) in seawater, mussels 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. Attribute information: "region" = name of subbasin "country" = country "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter (CD = Cadmium) "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 effort (hours/c-square) for mobile bottom-contacting gear in 2011based on VMS/Log book data processed by ICES Working Group on Spatial Fisheries Data (WGSFD). HELCOM requires spatially explicit information on fishing activity affecting the Baltic Sea marine ecosystem for policy purposes. In order to obtain this information a joint ICES/HELCOM/OSPAR data call was issued to relevant authorities of contracting parties to deliver information on fishing activity based on VMS/Log book data. The raw data was submitted to ICES and processed to advice data products by ICES Working Group for Spatial Fisheries (WGSFD) as requested by HELCOM. Processing of the raw data requires specific resources, knowledge and guarantee of anonymity for specific vessels, thus the process was done by ICES WGSFD following Conditions for VMS data use. In 2015 ICES collated Vessel Monitoring System (VMS) and logbook data received; data from Russia were not received. ICES provided to HELCOM advice as fishing abrasion pressure maps as well as fishing effort maps. HELCOM secretariat did the following processing to the data: - 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 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 Year: Year of fishing activity quarter: Quarter of the year, if applicable geargroup: Fishing gear group (Effort maps) SubsurfSAR: Subsurface swept area ratio (Intensity maps) SurfSAR: Surface swept area ratio (Intensity maps) Fishing_ho: Total fishing effort in hours within c-square (Effort maps) Reported: Yes=Reported data. No= No reported data (area that does not contain effort/intensity value due to lack of reported data.

This dataset describes fishing effort (hours/c-square) for longlines in 2013 based on VMS/Log book data processed by ICES Working Group on Spatial Fisheries Data (WGSFD). HELCOM requires spatially explicit information on fishing activity affecting the Baltic Sea marine ecosystem for policy purposes. In order to obtain this information a joint ICES/HELCOM/OSPAR data call was issued to relevant authorities of contracting parties to deliver information on fishing activity based on VMS/Log book data. The raw data was submitted to ICES and processed to advice data products by ICES Working Group for Spatial Fisheries (WGSFD) as requested by HELCOM. Processing of the raw data requires specific resources, knowledge and guarantee of anonymity for specific vessels, thus the process was done by ICES WGSFD following Conditions for VMS data use. In 2015 ICES collated Vessel Monitoring System (VMS) and logbook data received; data from Russia were not received. ICES provided to HELCOM advice as fishing abrasion pressure maps as well as fishing effort maps. HELCOM secretariat did the following processing to the data: - 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 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 Year: Year of fishing activity quarter: Quarter of the year, if applicable geargroup: Fishing gear group (Effort maps) SubsurfSAR: Subsurface swept area ratio (Intensity maps) SurfSAR: Surface swept area ratio (Intensity maps) Fishing_ho: Total fishing effort in hours within c-square (Effort maps) Reported: Yes=Reported data. No= No reported data (area that does not contain effort/intensity value due to lack of reported data.