This dataset contains datasets for the Eutrophication assessment developed under the HELCOM Third Holistic Assessment of the Ecosystem Health of the Baltic Sea (HOLAS 3). The dataset contains all Baltic Sea monitoring CTD data reported by HELCOM Contracting Parties to ICES for the HOLAS3 assessment period 2016-2021. The data have been reported using the ICES Ocean reporting format: https://www.ices.dk/data/data-portals/Pages/ocean-format.aspx https://www.ices.dk/data/Documents/ocean/ICES-Oceanography-Data-Submission-Format.zip

Springtime Chl-a concentration is here used as a proxy for productive surface waters. In the Baltic Sea Spatial Pressure and Impact Index (SPIA), areas with high springtime phytoplankton production will be given higher importance, as they are considered important areas for the Baltic Sea food web. In the current map, mean of springtime maximum weekly values (weeks 12-22 for the HOLAS3 assessment period 2016-2021). Satellite Chl-a concentration of the surface waters has been used and converted to index by Finnish Environment institute with resolution of 1 km x 1 km grid cells.

This dataset represents the underlying sediment data on core indicator Polyaromatic hydrocarbons (PAH) and their metabolites. The core indicator evaluates the status of the marine environment based on concentrations of Polyaromatic hydrocarbons (PAH) in sediment and biota. Quantitative threshold value is used to evaluate if core indicators status is Achieve, Fail or Not assessed. As There is no commonly agreed threshold value for measuring metabolites available, this report only considers concentrations of contaminants. 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 information: "region" = name of subbasin "country" = country "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter (ANT = anthracene) "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 pressure dataset is derived from three human activities datasets - Urban land use (on land) - Recreational boating and sports (updated layer for 2018 version, please see separate http://metadata.helcom.fi/geonetwork/srv/eng/catalog.search#/metadata/8c30e828-1340-4162-b7f9-254586ae32b6) - Bathing sites These data are described in more detail in separate fact sheets. Urban land use data was first converted to 1 km grid cells and expanded with 1 km. Thus, coastal urban areas extended also to the sea. These areas were given value 1 and other sea areas, value 0. Bathing sites (points) were converted to 1km grid and given value 1, rest of the sea areas were given value 0. Normalized recreational boating data was converted to 1 km grid cells. These three layers were summed to produce the layer (values from 0 to 3), after that the layer was normalized. Hunting and recreational fishing data were excluded from human disturbance layer, as they are mostly reported per country and would have resulted in overestimation of the actual pressure.

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 represents the underlying data on core indicator 'Reproductive disorders: malformed embryos of amphipods 2018'. The core indicator evaluates the status of the marine environment based on the presence of hazardous substances in the bottom sediments. The rate of embryo malformations indicates reproductive toxicity due to the presence of hazardous substances in the bottom sediments. The threshold value has not been achieved on all stations within each basin indicating that toxic effects of contaminants may be present. The variability of the malformation rate is much greater within a basin than between the Bothnian Sea and the Baltic proper. This dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "YEAR" = Year of sampling "Basin" = Subbasin abbreviation "REGION" = Region code within the Baltic Sea "STATN" = Station "Lat_WGS84d" = latitude coordinate of station "Lon_WGS84d" = longitude coordinate of station "TotalEmbry" = Total embryos "UNDIFFiren" = Undifferentiated "MALFORmed" = Malformed "MEMBraneDa" = Membrane damage "FemalesWME" = Females with malformed embryos "NofFemales" = Number of Females "AveFecundi" = Average Fecundity "STN" = "FFemWAE" = Frequency Females with aberrated embryos "FreqAberrE" = Frequency Aberrant Embryos "inGES_Fem" = inGES (Females) "inGES_Emb" = inGES (Embryos) "inGES_Over" = inGES (overall)

This indicator evaluates the eutrophication status of the Baltic Sea area based on water clarity measured by secchi depth during summer. The measured average secchi depth (in meters) is based on in-situ measurements from oceanographic monitoring data for 2011-2016 summer months (June-September). More detailed description on methodology can be found at http://www.helcom.fi/baltic-sea-trends/indicators/water-clarity 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/ opensea "level_2" = Name of the HELCOM scale 2 assessment unit "Name" = Name of the HELCOM scale 4 assessment unit” "Area (km2)" = Area of the HELCOM scale 2 assessment unit "Method" = Name of method use to define indicator “Season” = Season of the indicator (Summer = June-September) “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 "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” or “Low”) "AULEVEL" = Assessment unit level used for the indicator

This indicator evaluates the eutrophication status of the Baltic Sea area based on annual total phosphorus concentration. The measured average total phosphorus on in-situ measurements from oceanographic monitoring data for 2011-2016 (µmol/l), surface water (0-10 m). More detailed description on methodology can be found at http://www.helcom.fi/baltic-sea-trends/indicators/total-phosphorus-(tp)/ 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. Some of the open sea areas have not been assessed due to lack of commonly agreed threshold value. Attribute information: “HELCOM_ID” = Code of the HELCOM scale 4 assessment unit "Country" = Country/ Opensea "level_2" = Name of the HELCOM scale 2 assessment unit "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 (Summer = June-September) “Period” = Assessment unit period start and end year (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 "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 (“Good”, “Not good”, “Not assessed” or "Not applicable") “Confidence” = Confidence of result based on I-SCORE (“High”, “Moderate” or “Low”) "AULEVEL" = Assessment unit level used for the indicator "Winter status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) in winter "Winter ratio between ES and ET (ER)" = Ratio between ES and ET (in case of indicator with positive response to eutrophication) in winter "Winter indicator value (ES)" = Commonly agreed thershold value in winter

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 flatfish. Attribute information: "HELCOM_ID" = Code of the HELCOM scale 2 assessment unit "level_2" = Name of the HELCOM scale 2 assessment unit (subbasin) "Indicator" = Name of HELCOM Core indicator "Type" = Type of indicator "Threshold value" = Threshold value for specific assessment unit "Indicator value" = Value of indicator calculated for specific assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”)

This dataset contains the in-situ monitoring data used for calculating eutrophication indicator results for following indicators: Chlorophyll-a 2018 Dissolved inorganic nitrogen 2018 Dissolved inorganic phosphorus 2018 Total nitrogen 2018 Total phosphorus 2018 Water clarity 2018 This dataset is extraction for 2011-2016 assessment period from HELCOM COMBINE database, which contains all HELCOM oceanographic monitoring data. Full COMBINE database can be accessed from dedicated web page Attribute information: "Cruise": Platform code of the monitoring cruise, which can be queried from http://vocab.ices.dk/ "Station": Station number "Year": Year of sampling event "Month": Month of sampling event "Day": Day of sampling event "Hour": Hour of sampling event "Minute": Minute of sampling event "Latitude": Latitude coordinate of the sampling location (WGS84 decimal degrees) "Longitude": Longitude coordinate of the sampling location (WGS84 decimal degrees) "BotDepth": Bottom depth (m) of sampling location "Secchi": Secchi depth at sampling location "StationNam": Station name from ICES Station dictionary "Assessment" = HELCOM assessment unit ID "Depth": Sampling depth (m) "Temperature": Temperature (ºC) "Salinity": Salinity "Oxygen": Oxygen (ml/l) "Phosphate": Phosphate (umol/l) "TotalPhos": Total phosphorus (umol/l) "Silicate": Silicate (umol/l) "Nitrate": Nitrate (umol/l) "Nitrite": Nitrite (umol/l) "Ammonium": Ammonium (umol/l) "TotalNitr": Total nitrogen (umol/l) "HydrogenS": Hydrogen sulphide (umol/l) "pH": pH "Alkalinity": Alkalinity (mEq/l) "Chlorophyl": Chlorophyll-a (ug/l)