Observations of Fucus serratus were collected from the Baltic Sea area for HELCOM Red List species list. The HELCOM Red List of Baltic Sea species in danger of becoming extinct (2013) is the first threat assessment for Baltic Sea species that covers all marine mammals, fish, birds, macrophytes (aquatic plants), and benthic invertebrates, and follows the Red List criteria of the International Union for Conservation of Nature (IUCN). Almost 2800 species were considered in the Red List assessment and about 1750 were evaluated according to the IUCN Red List criteria. Fucus serratus has been placed to the Red List category of Least Concern (LC) species. Dataset for download contains spatial grid of the Baltic Sea. Distribution of the species can be found in corresponding name column. Values are coded: 0 = no observations 1 = present before year 1995 or in 1995 2 = present after year 1995 3 = present before and after year 1995

This dataset contains results on HELCOM Assessment unit level 4b for water clarity. The information provided represents the data and results from the HELCOM HOLAS 3 indicator evaluation for eutrophication, covering the data period from 2016-2021. Data reported from national monitoring programmes to the HELCOM COMBINE database (hosted by ICES) is utilized for open sea assessment units. Open sea data extraction is carried out by ICES for in-situ (bottle) data creating the underlying assessment dataset [link ]. Coastal assessment units (WFD water types or water bodies) are assessed based on WFD result data reported by countries. Indicator analysis of both open sea and coastal areas is carried out using the HEAT assessment tool (https://github.com/ices-tools-prod/HEAT). This analysis provide the basis of the HELCOM indicator evaluations and are utilized in the HOLAS 3 thematic assessment of eutrophication. Attribute description: ES = Eutrophication Status ES_SD = Standard Deviation ES_N = Number of Observations ES_N_Min = Minimum Number of Observations any given year ES_SE = Standards Error ES_CI = Confidence Interval ET = Eutrophication Target / Threshold ER = Eutrophication Ratio ACDEV = Acceptable Deviation BEST = ET / (1 + ACDEV / 100) EQR = Ecological Quality Ratio EQR_HG = Ecological Quality Ratio High/Good Boundary EQR_GM = Ecological Quality Ratio Good/Moderate Boundary EQR_MP = Ecological Quality Ratio Moderate/Poor Boundary EQR_PB = Ecological Quality Ratio Poor/Bad Boundary EQRS = Ecological Quality Ratio Scaled GTC = General Temporal Confidence STC = Specific Temporal Confindence TTC = Total Temporal Confidence GSC = General Spatial Confidence SSC = Specific Spatial Confidence TSC = Total Spatial Confidence TC = Total Confidence

This core indicator evaluates the state of the marine environment using distribution of the three species of seals that occur in the Baltic Sea. This dataset is for the Harbour seal. Quantitative thresholds are used to evaluate the core indicators status in "Achieve", "Fail" or "Not assessed". The core indicator has three components for each species: distribution of haul-out sites, breeding sites and foraging areas. Good status is achieved when the distribution of seals is close to pristine conditions (e.g. 100 years ago), or where appropriate when currently available haul-out sites are occupied (modern baseline), and when no decrease in area of occupation occurs. The current evaluation covers the assessment period 2011-2016. This 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 scale 2 assessment unit "Name" = Name of the HELCOM scale 2 assessment unit "Status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator

Dataset description: The dataset contains data on locations of river monitoring stations of nutrients and hazardous substances inputs to the Baltic Sea reported to the HELCOM Pollution Load Compilation (PLC-water) database. The stations are categorized as hydrological (only flow monitoring) and chemical (monitoring of chemical components). The data is reported to the HELCOM database and quality assured by Contracting Parties to HELCOM in accordance with the HELCOM Guidelines for the annual and periodical compilation and reporting of waterborne pollution inputs to the Baltic Sea (PLC-Water Guidelines). Dataset content: Station code (st_code): unique HELCOM PLC code Station name (st_name). River code (r_code): unique HELCOM PLC code. Sub catchment code (subc_code): unique HELCOM PLC code Country code (c_code): DK; EE; FI; DE; LV; LT; PL; RU; SE. Sub-basin code (subb_code): ARC; BAP; BOB; BOS; GUF; GUR; KAT; SOU; WEB. Station category (st_cat): hydrological (H) and chemical (C). Latitude (st_lat). Longitude (st_lon). Reporting year (year). Country codes used in the dataset correspond to: DK-DENMARK; EE-ESTONIA; FI-FINLAND; DE-GERMANY; LV-LATVIA; LT-LITHUANIA; PL-POLAND; RU-RUSSIA; SE-SWEDEN. The Baltic Sea sub-basin codes used in the dataset are: ARC-ARCHIPELAGO SEA; BAP-BALTIC PROPER; BOB-BOTHNIAN BAY; BOS-BOTHNIAN SEA; GUF-GULF OF FINLAND; GUR-GULF OF RIGA; KAT-KATTEGAT; SOU-SOUND; WEB-WESTERN BALTIC. Visualization: Map - point feature class. Legend visualizes two categories of monitoring station: hydrological, chemical. Data update: Metadata is updated by HELCOM Secretariat annually by 1 April. The dataset is updated by HELCOM Secretariat annually by 1 April.

The pressure layer represents biological pressure caused by introduction of non-indigenous species. The data is obtained from core indicator Trend in the arrival of new non-indigenous species (BSEP 129b: http://www.helcom.fi/Lists/Publications/BSEP129B.pdf). For the Baltic Sea Impact Index, the layer was normalized.

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 Seasonal succession of dominating phytoplankton groups for HOLAS 3. 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" =

This dataset represents the underlying data on core indicator Trends in arrival of new non-indigenous species for HELAS 3. 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 data on core indicator Abundance of waterbirds in the breeding season 2018. The data is resulting from a data call carried out by HELCOM for State of the Baltic Sea report. Attribute information: "YEAR" = Year of the observation "SPECIES" = Species accepted scientific name "ABUNDANCE" = Abundance count "Country" = Country of observation "SITECODE" = Unique site code

This core indicator evaluates the status of abundance of wintering waterbirds in the Baltic Sea region, here visualizedfor pelagic feeders. The wintering 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 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 "Group area" = Name of the group area "level_2" = Name of scale 2 HELCOM assessment unit (subbasin) "level_3" = Name of scale 3 HELCOM assessment unit "Area (km2)" = Area of HELCOM assessment unit "coastal" = HELCOM ID of the coastal areas "open_sea" = Open sea assessment unit name "Abundance" = Assessed parameter "Threshold" = Threshold value "Wading feeders" = Results for the category "Wading feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Surface feeders" = Results for the category "Surface feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Pelagic feeders" = Results for the category "Pelagic feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Benthic feeders" = Results for the category "Benthic feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "Grazing feeders" = Results for the category "Grazing feeders status" = Status of the indicator (“Achieve”, “Fail” or “Not assessed”) "AULEVEL" = Assessment unit level used for the indicator