Concentration of nitrogen pressure layer is interpolated from annual seasonal average of total nitrogen concentrations from surface waters (0-10 m) extracted from ICES’s oceanographic database, database of Swedish Meteorological and Hydrological Institute, EEA’s Eionet database and Data from Gulf of Finland year 2014. The points were interpolated to cover the entire Baltic Sea with Spline with barriers interpolation method. Values were log-transformed and normalised (more detailed description below).

This dataset describes fishing intensity for SDN DMF 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.

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 2016-2021. This dataset displays the result of the indicator for cyprinids/ mesopredators 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" = ID of the HELCOM scale 3 assessment unit "country" = Country/ Opensea "level_2" = Name of scale 2 HELCOM assessment unit "level_34" = Name of scale 3 HELCOM assessment unit "coast" = Code of scale 3 HELCOM assessment unit "open_sea" = Name of Open sea HELCOM assessment unit "SAUID" = "SAUlevel" = "Indicator" = Name of the indicator "ECID" = Ecosystem component ID "EClevel" = Ecosystem component level "EcosystemC" = Ecosystem Component "EQR" = Ecological Quality Ratios "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”)

Summary Estimated observations of the biotope AB.H4U1 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic muddy sediment dominated by meiofaunaThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AB.H4U1 according to HELCOM RED LIST assessment experts:The biotope is assumed to occur throughout the Baltic Sea both in shallow coastal waters and in the deeper central parts of the sea. The distribution map indicates the area in the 100 x 100 km grid where biotope is reported to occur. The biotope may have a significantly wider distribution.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

This dataset describes fishing effort (hours/c-square) for midwater trawl 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.

This core indicator evaluates the status of the marine environment based on concentrations of radioactive substances (Cs-137) in seawater and biota. Quantitative thresholds are used to evaluate if core indicators status is "Achieve", "Fail" or "Not assessed". Good status is achieved when concentrations reach levels measured before the Chernobyl accident in 1986. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins) for seawater. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 2 assessment unit "level_2" = name of the HELCOM scale 2 assessment unit (subbasin) "area_km2" = Area of HELCOM assessment unit "Indicator" = name of the indicator "Unit" = Unit used for the measured parameter "Type" = type of the indicator "Threshold value" = Threshold value for the subbasin "Indicator value" = Indicator value (result) for the subbasin "STATUS" = Status of the indicator in seawater (“Achieve”, “Fail” or “Not assessed”)

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 all dioxinsstations by sub-basin in the Baltic Sea as reported to the HELCOM MORE project.

This core indicator evaluates the status of the marine environment based on concentrations of heavy metal Lead (Pb) in water. Quantitative thresholds are used to classify core indicators status in “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. This dataset 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 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 describes fishing intensity for SDN DMF mobile bottom contacting gear in 2014 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.