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 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 indicator evaluates the eutrophication status of the Baltic Sea area based on dissolved inorganic phosphorus (DIP) concentration. The measured average DIP is based on in-situ PO4 measurements from oceanographic monitoring data for winter period (December-February) 2011-2016 (umol/l), surface water (0-10 m). More detailed description on methodology can be found at http://www.helcom.fi/baltic-sea-trends/indicators/Dissolved-inorganic-phosphorus-(DIP) and http://www.helcom.fi/Documents/Eutrophication%20assessment%20manual.pdf This dataset displays the result of the indicator in HELCOM Assessment Scale 4 (Division of the Baltic Sea into 17 open sea sub-basins and division of coastal areas to WFD water types or water bodies). The open sea areas have been assessed based on HELCOM Monitoring data and results for coastal areas are based on national WFD results. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 4 assessment unit "Country" = country "level_2" = name of subbasin "name" = Name of the HELCOM scale 4 assessment unit "Area (km2)" = Area of the HELCOM scale 2 assessment unit "Indicator" = Name of indicator “Season” = Season of the indicator (Winter = December-February) “Period” = Assessment unit period (20112016 = 2011 – 2016) Indicator value (ES) = Indicator value calculated for the assessment unit "Standard deviation (STD)" = Standard deviation of data used for calculating ES "Number of samples " = Number of samples in assessment unit "Thershold value (ET)" = Commonly agreed thershold value "Ratio between ES and ET (ER)" = Ratio between ES and ET (in case of indicator with positive response to eutrophication) "ES_SCORE” = Confidence based on the data used for calculating ES "ET_SCORE” = Confidence of target-setting procedure "I_SCORE” = Confidence (%) = average of ES-Score and ET-Score "Indicator Weight" = Indicator Weight in integrated eutrophication assessment “Status” = Status of the indicator (“Achieve”, “Fail”, “Not assessed” or "Not applicable") “Confidence” = Confidence of result based on I-SCORE (“High”, “Moderate”, “Low” or "Not assessed") "AULEVEL" = Assessment unit level used for the indicator

This dataset describes fishing intensity for Seine mobile bottom contacting gear in 2011 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 water 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 "filtered" = Filtered or unfiltered water sample used in analysis "_shape2 = 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 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 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_3" = Name of scale 3 HELCOM assessment unit "Area (km2)" = Area of the HELCOM scale 3 assessment unit "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 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 core indicator evaluates the status of the marine environment based on concentrations of polyaromatic hydrocarbons PAHs - Anthracene in sediment. Quantitative thresholds are used to evaluate if core indicators status is "Achieve", "Fail" or "Not assessed". 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) "colour" = symbology "Status" = Overall Status of the indicator according to one-out-all-out

This core indicator evaluates the status of abundance of breeding waterbirds in the Baltic Sea region. The breeding waterbirds are considered to reflect good status when at least 75% of the considered species deviate less than 30% downwards (species laying more than one egg per year) or 20% downwards (species laying one egg per year) from the baseline condition during the reference period 1991-2000. This dataset displays the result of the indicator in HELCOM Assessment Scale 1 (Whole Baltic Sea). Attribute information: "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator "level_1" = Name of HELCOM scale 1 assessment unit "Common Shelduck" = Results for common shelduck "Eurasian Oystercatcher" = Results for Eurasian oystercatcher "Pied Avocet" = Results for pied avocet "Ringed Plover" = Results for ringed plover "Turnstone" = Results for turnstone "Dunlin" = Results for dunlin "Arctic Skua" = Results for Arctic skua "Common Gull" = Results for common gull "Herrin Gull" = Results for herring gull "Lesser black-backed gull" = Results for lesser black-backed gull "Little Tern" = Results for little tern "Caspian Tern" = Results for Caspian tern "Arctic Tern" = Results for Arctic tern "Goosander" = Results for goosander "Red-breasted Merganser" = Results for red-breasted merganser "Great crested grebe" = Results for great crested grebe "Great Cormorant" = Results for great cormorant "Razorbill" = Results for razorbill "Common Guillemot" = Results for common guillemot "Black Guillemot" = Results for black guillemot "Tufted Duck" = Results for tufted duck "Common Eider" = Results for common eider "Velvet Scoter" = Results for velvet scoter "Mute Swan" = Results for mute swan "Graylag Goose" = Results for greylag goose "Great black-backed Gull" = Results for great black-backed gull "Sandwich Tern" = Results for sandwich tern "Greater Scaup" = Results for greater scaup

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