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.

The aim of HELCOM Biodiversity database is to collate all available species observation data made available by HELCOM Contracting Parties. The database contains +1M species observations and applies World Register of Marine Species (WoRMS) taxonomy. The data model used is based on Darwin Core format, with required extensions added. Species observations are mostly pointwise observations, but also gridded observations are included for some species. The database can be searched, viewed and downloaded using a specific web application. The whole database can be downloaded as a zipped ESRI File geodatabase. Disclaimer: Data in the database is stemming from various sources. While there has been considerable quality assurance efforts, the accuracy of data can not be quaranteed. Note that HELCOM Contracting Parties report open sea observations on zoobenthos, zooplanton and phytoplantkon to ICES Dome database and those observations are not included in HELCOM Biodiversity database. Biodiversity database attribute description is available below: attrribute; type (description): origin_of_data_collection; Text (Origin of data call / data collection project from which the observation has been obtained) aphiaID; Number (WoRMS AphiaID or species which is used to retrieve taxonomy information from WoRMS webservice) scientific_name; Text (Scientific name of the species as reported in source data) taxonomical_status; Text (Taxonomical status of Scientific name according to WoRMS) accepted_name; Text (Accepted name of the AphiaID according to WoRMS) species_group; Text (Species group of the AphiaID) synonyms; Text (Synonyms of AphiaID according to WoRMS) data_source; Text (Data provider organization) subunit; Text (Further explanation about any subunits or groups of the institution that are responsible for the data submission.) field_number; Text (unique identifier, number or text or combination, created at collection time to identify each observation, e.g. sample numbers) count_value; Number: Number of individuals: Count value (integer) count_unit; Text: Unit of count value count_estimate; Codelist: Total, Modelled, Maximum, Minimum, C-POD, Null. If not available, use Null count_method; Text. Count method as free text decimal_latitude; Number (Latitude coordinate of observation location in WGS84 decimal degrees, 6 decimals) decimal_longitude; Number (Longitude coordinate of observation location in WGS84 decimal degrees, 6 decimals) coordinate_uncertainty; Number (The horizontal distance (in meters) from the given decimal_latitude and decimal_longitude describing the smallest circle containing the whole of the Location. Leave the value empty if the uncertainty is unknown, cannot be estimated, or is not applicable (because there are no coordinates). Zero is not a valid value for this term. polygon_id_1x1km; ID of the polygon to which observations are within (EEA grid) polygon_id_2x2km; ID of the polygon to which observations are within (EEA grid) polygon_id_5x5km; ID of the polygon to which observations are within (EEA grid) polygon_id_10x10km; ID of the polygon to which observations are within (EEA grid) data_generalization; Text (Codelist: no data generalization, data aggregation as grid (1x1km), data aggregation as grid (2x2km), data aggregation as grid (5x5km), data aggregation as grid (10x10km), Other, please specify in the "Notes" section) year_collected; Number (Year as in YYYY) month_collected; Number (Month as in MM) day_collected; Number (Day as in DD) start_day_collected; Number (Year as in YYYY, used if not a date for sampling but rather a time frame exists. Starting year for that sampling period) start_month_collected; Number (Month as in MM, used if not a date for sampling but rather a time frame exists. Starting month for that sampling period) start_day_collected; Number (Day as in DD, used if not a date for sampling but rather a time frame exists. Starting day for that sampling period) end_year_collected; Number (Year as in YYYY, used if not a date for sampling but rather a time frame exists. Last year for that sampling period) end_month_collected; Number (Month as in MM, used if not a date for sampling but rather a time frame exists. Last month for that sampling period) end_day_collected; Number (Day as in DD, used if not a date for sampling but rather a time frame exists. Last day for that sampling period) notes; Text (Any other information) citation; Text. If specific citation should be used for observation, it should be described here restriction; Yes/No (No, if no restrictions on use. Yes, if any information restricted for this observation, that cannot be shared freely) restriction_description; Free text (If Restriction=Yes, then describe the reason and type of restriction) information_withheld; Text (Codelist: no information withheld, Location information aggregated, Location information aggregated and more detailed information can be asked from the Institution, Other, please specify in the "Notes" section

This online application serves as a joint regional tool to identify low risk routes for IMO Ballast Water Convention exemptions (A-4) for HELCOM and OSPAR marine areas. Data are provided following the port survey protocol described in the HELCOM/OSPAR Joint Harmonised Procedure. https://helcom.fi/wp-content/uploads/2021/01/HELCOM-OSPAR-Joint-Harmonized-Procedure-for-BWMC-A-4-exemptions_2020.pdf The database contains environmental data recorded from OSPAR and HELCOM ports as well as species observations and applies World Register of Marine Species (WoRMS) taxonomy. The data model used is based on Darwin Core format, with required extensions added. The database can be searched, viewed and downloaded using a specific web application. The whole database can be downloaded as a zipped ESRI File geodatabase. The HELCOM/OSPAR Ballast Water Exemptions Decision Support Tool was further developed in the EU INTERREG Baltic Sea Region project COMPLETE, following work developed with funding through the HELCOM ALIENS 2 and 3 and BALSAM projects by the HELCOM Secretariat and Germany (BSH/Brockmann consult). The data contained in the database are resulting from various sources and contains also historical legacy data from old projects. Main sources are listed below: - HELCOM and OSPAR countries national projects - HELCOM ALIENS 2 - HELCOM ALIENS 3 - HELCOM BALSAM

The layer presents the cumulative negative impacts on marine biodiversity caused by alien species in the Baltic Sea. The layer is based on the Cumulative IMPact of ALien species (CIMPAL) index, developed by Katsanevakis et al. (2016). The original methodology was applied for the Baltic Sea similarly as Korpinen et al. (2019) applied it for the EU waters in their report Multiple pressures and their combined effects in Europe’s seas. The list of species and habitats together with the sensitivity scores are originating from this study and listed in the linage section of this metadata. The index follows a conservative additive model for calculating the cumulative negative impacts of invasive alien species (IAS), based on magnitude of impact and the related strength of evidence following an uncertainty averse strategy. Cumulative impacts of IAS were estimated on the basis of the distributions of invasive species and ecosystems, and both the reported magnitude of ecological impacts and the strength of such evidence. 29 invasive species and 12 habitats were used for the layer, detailed information on the species, habitats and sensitivity scores used in the assessment are given in the lineage section. The information on species and habitats were aggregated to 10x10 km grid, based on their occurrence within each grid cell. Calculation of the index was done with the HELCOM SPIA tool, and the result were converted to the 1x1km SPIA grid. The layer was normalized to be used in the assessment.

Observations of Fucus vesiculosus 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