This dataset represents the integrated assessment of hazardous substances in the Baltic Sea in 2016-2021. This dataset displays the result of the assessment in HELCOM Assessment unit Level 3 (Division of the Baltic Sea into 17 sub-basins and further division into coastal and offshore areas).

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 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 contains integrated eutrophication status assessment 2011-2016, visualized for indirect effects (C3_ER). The assessment is done on HELCOM Assessment Unit level 4: HELCOM Subbasins with coastal WFD water type or water bodies. The HEAT 3.0 has been applied for open sea assessment units using HELCOM core indicators and for coastal areas using national WFD indicators. For more information about the methodology, see State of the Baltic Sea report and HELCOM Eutrophication assessment manual. Attribute information: "HELCOM_ID": ID of HELCOM Level 4 Assessment unit "Country": Country / opensea "level_2": Name of HELCOM Level 2 Assessment unit "Name": Name of HELCOM Level 4 Assessment unit "Area_km2" : Area of assessment unit "C1_N": Criteria 1, number of indicators used for calculating Eutrophication Ratio (ER) "C1_ER": Criteria 1, ER "C1_SCORE": Criteria 1, Confidence of ER "C2_N": Criteria 2, number of indicators used for calculating ER "C2_ER": Criteria 2, ER "C2_SCORE": Criteria 2, Confidence of ER "C3_N": Criteria 3, number of indicators used for calculating ER "C3_ER": Criteria 3, ER "C3_SCORE": Criteria 3, Confidence of ER "N": Number of criteria used for calculating overall ER "ER": Overall ER "SCORE": Status confidence "STATUS": Status classification (Good (classes 0-0.5 & 0.5-1.0), Not Good (classes 1.0-1.5, 1.5-2.0 & >2.0), Not assessed) "CONFIDENCE": Final confidence rating (< 50% = low, 50-74 % = Moderate, = 75 % = High) "AULEVEL": Level of assessment units

The Diatom/Dinoflagellate index (Dia/Dino index) reflects the dominance patterns in the phytoplankton spring bloom. It has high relevance for the pathway of the food into the pelagic or benthic food web. In principle, the indicator is applicable in all coastal and open sea assessment units, except lagoons, large river plumes and the Bothnian Bay; however, thresholds for the good status are defined only for the southern and central Baltic Sea up to now. The indicator is not yet agreed as a HELCOM core indicator but is tested in the HOLAS II project for the Eastern Gotland Basin. In this assessment unit, the average Dia/Dino index of the years 2011-2016 was just below the threshold value of 0.5 for good status. The confidence of the indicator evaluation depends on the data frequency. The data have to represent the diatom and dinoflagellate blooms adequately. If the diatom bloom is not sufficiently represented in the data, an alternative Dia/Dino index may be applied, based on silicate consumption data. This indicator is robust; its calculation is simple and traceable. The phytoplankton monitoring is operational in the whole Baltic Sea using methods prescribed in the COMBINE manual. Currently, a high quality of the data is assured by the experts of the HELCOM Phytoplankton Expert Group (PEG). The basic data are phytoplankton biomass data, determined as explained in the HELCOM COMBINE manual, originating from the depth of 0 – 10 m. Also silicate data were used that were taken parallel to the phytoplankton sampling. Diatom-dinoflagellate ratio dataset displays the result of the indicator in HELCOM Assessment Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "HELCOM_ID" = ID of the HELCOM scale 2 assessment unit "Area (km2)" = Area of the HELCOM assessment unit "Name" = Name of the HELCOM scale 2 assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Threshold value" = Threshold value of indicator "Unit" = Unit of the indicator "Indicator value" = Result of the indicator "AULEVEL" = Assessment unit level used for the indicator

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 contains data used for assessing the HELCOM core indicator Nutritional status of seals 2018. The data has been collated by indicator leads based on national monitoring data. For this dataset, the data is aggregated and summarized by ICES Subdivisions. Attribute information: "Major_FA": FAO Major Area "SubArea": FAO Subarea "Division": ICES division "SubDivisio": ICES sub-division "Unit" "Area_full" "Area_27" "Area_km2": Area of ICES sub-division "ICES_SD": ICES sub-division "Female": Number of females per ICES sub-division "Male": Number of males per ICES sub-division "F1_year_ol": Number of 1 year old individuals per ICES sub-division "F2_year_ol": Number of 2 year old individuals per ICES sub-division "F3_year_ol": Number of 3 year old individuals per ICES sub-division "n_hunted": Number of hunted individuals per ICES sub-division "n_by_caught": Number of by caught individuals per ICES sub-division "n_stranded": Number of stranded individuals per ICES sub-division "Length_100": Number of individuals with 100 to 110 cm length per ICES sub-division "Length_111": Number of individuals with 111 to 120 cm length per ICES sub-division "Length_121": Number of individuals with 121 to 130 cm length per ICES sub-division "Length_131": Number of individuals with 131 to 140 cm length per ICES sub-division "Length_141": Number of individuals with 141 to 150 cm length per ICES sub-division "Length_151": Number of individuals with 151 to 160 cm length per ICES sub-division "Length_161": Number of individuals with 161 to 170 cm length per ICES sub-division "Length_171": Number of individuals with 171 to 180 cm length per ICES sub-division "Length_mor": Number of individuals with more than 181 cm length per ICES sub-division "Data_sourc": Data provider "Data_origi": Country of the data "Data_restr": Data restriction "Blubber_10": Number of individuals with measured blubber of 10 to 20 mm "Blubber_21": Number of individuals with measured blubber of 21 to 30 mm "Blubber_31": Number of individuals with measured blubber of 31 to 40 mm "Blubber_41": Number of individuals with measured blubber of 41 to 50 mm "Blubber_51": Number of individuals with measured blubber of 51 to 60 mm "Blubber_61": Number of individuals with measured blubber of 61 to 70 mm

This dataset represents the Integrated biodiversity status assessment for grey seals. Status is shown in five categories based on the integrated assessment scores obtained in the tool. Biological quality ratios (BQR) above 0.6 correspond to good status. The status of the grey seals was assessed using four core indicators: - Population trends and abundance of seals - Distribution of Baltic seals - Nutritional status of seals - Reproductive status of seals. The assessment is based on the one-out-all-out approach, i.e. the indicator reflecting the worst status in each assessment unit. This dataset displays the result of the integrated biodiversity status in HELCOM Assessment unit Scale 2 (Division of the Baltic Sea into 17 sub-basins). Attribute information: "HELCOM_ID" = ID of the HELCOM scale 2 assessment unit "level_2" = Name of the HELCOM scale 2 assessment unit "EcosystemC" = Ecosystem component analyzed "BQR" = Biological Quality Ratio "Conf" = Confidence of the assessment "Total_indi" = Number of indicators used "Area_km2" = Area of scale 2 assessment unit "F_of_ar_1" = Share of total area assessed "D1CX" = MSFD descriptor 1 criteria X "conf_D1C_1" = Confidence of the MSFD descriptor 1 criteria 2 "STATUS" = Status assessment category (0-0.2 = not good (lowest score), 0.2-0.4 = not good (lower score), 0.4-0.6 = not good (low score), 0.6-0.8 = good (high score, 0.8-1.0 = good (highest score))

This dataset represents the underlying data on core indicator Trends in arrival of new non-indigenous species 2018. This dataset contains reported observations of alien species on HELCOM Assessment unit level 2. The core indicator evaluates status of arrival of new non-indigenous species whether it reflects good environmental status. Quantitative thresholds are used to evaluate if core indicators status is Good, Not good or Not assessed. The assessment is done for HELCOM Assessment unit level 1 (whole Baltic Sea). Attribute information: "HELCOM_ID" = ID of HELCOM Level 2 assessment unit "Level_2" = Name of assessment unit "Area_km2" = Area of assessment unit "Threshold_v" = Threshold value (0 = no alien species observed) "Observatio" = Observed value (0 = no alien species observed, 1 = alien species observed) "Confidence" = Confidence of assessment "Species" = Species observed in assessment unit "Status" = Status of assessment unit (Fail / Achieve / Not assessed) "AULEVEL" = Level of the Assessment unit

This dataset represents the underlying biota data on core indicator Polybrominated diphenyl ethers (PBDE) .The core indicator evaluates the status of the marine environment based on concentrations of Polybrominated diphenyl ethers (PBDE) in biota and sediment. Quantitative thresholds are used to evaluate if core indicators status is Achieve, Fail or Not assessed. 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/ opensea "station" = Unique code for the station "stationNam" = name for the station "determinan" = determinant parameter "detGroup" = the grouping of determinands used to display the results "species" = species of measurement "_shape" = shape used to map assessment results "colou"r = 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 "HQS" = Threshold value "HQSdiff" = difference between clLY and HQS "HQSbelow" = whether the mean value in the last monitoring year is significantly below HQS