Locations of the coastal protection structures. The dataset contains information about the coastal defence structure type and for some the structure length (m) and the year of construction. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Denmark, Estonia, Germany, Finland, Poland and Sweden. The activity was declared as not relevant in Lithuanian area. From Latvia and Russia no data was reported. Attribute specification and units Country: Country Type: Modification structure type Const_year: Year of construction Estimated: Estimated date of completion if under construction (Estonia) or the year of environmental permit if year of construction is lacking (Finland) Out_of_use: Year when costal defence structure has been taken out of use Measure: Additional information about the modification structure Length: Length of the modified coastline (m) width: Width of the modification structure (m) Area: Area of the modification structure (km2) X_Lon: Original X (Longitude) coordinate point (Finland)

Dataset contains the largest oil terminals in the Baltic Sea and the volume of oil transported through. The dataset was updated for HELCOM Assessments in 2016. The statistics cover years 1997, 2000 - 2008 (where available), and 2011-2013. The statistics for 2011-2013 were derived from Baltic Port Lists published by Centre for Maritime Studies, University of Turku. The dataset was updated for HELCOM Assessments in 2016. Attribute specification and units: YEAR1997…YEAR2013: Total (million tonnes) oil and oil products transported through the terminal during referred year.

Data set represents dredging activities around the Baltic Sea. The data set contains information about the dredging activity and for some the type (capital, maintenance) and the year of activity as reported by HELCOM Contracting Parties in response to data request. The dredging data is missing from Denmark.

Data of fish farming facilities along the Baltic coast. Annual and average finfish production and nutrient load (total phosphorus and total nitrogen) is given, if known. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Denmark, Finland, Germany and Sweden. The activity was declared as not relevant for Estonia, Latvia, Lithuania and Poland, thus there is no activity within those Contracting Parties. No data received from Russia. Nutrient inputs from fish farms in Denmark are calculated on the basis of production data. From Germany only the locations for the fish farming facilities are given. Information on the annual production and nutrient loads are confidential for reasons of competition and not accessible. Some numbers that were missing on nutrient input in Sweden have been calculated by SCB, Statistics Sweden (red numbers) based on average input/ amount produced fish. No exact area (km2) of the finfish mariculture was available, hence an estimate is given if been possible to calculate. Attribute specification and units: X_ETRS89: X coordinate point Y_ETRS89: Y coordinate point Subbasin: Baltic Sea sub basin Country: Country id (DK = Denmark, FI = Finland, SE = Sweden) County: County Name: Name of the fish farming company Comments: Notes regarding the data Area: Estimated area (km2) of finfish mariculture (value is given, if information was available) Pr_Sum_ton: Total (Sum) production in tonnes Pr_Av_ton: Average production (tonnes)/year P_Sum_ton: Total phosphorus load in tonnes P_Av_ton: Average phosphorus load (tonnes)/year N_Sum_ton: Total nitrogen load in tonnes N_Av_ton: Average nitrogen load (tonnes)/year Pr2011_ton – Pr2015_ton: Annual production (tonnes/year) P_2011_kg – P_2015_Kg: Annual phosphorus loading in kilograms (Kg P / year) N_2011_kg – N_2015_Kg: Annual nitrogen loading in kilograms (Kg N / year)

Constructed from EEA data on the status of bathing water. Downloaded from EEA homepage (http://www.eea.europa.eu/data-and-maps/data/bathing-water-directive-status-of-bathing-water-7). Contains information on the location and water quality of bathing sites 2011-2014. No data from Russia.

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.

Data for Furcellaria harvesting presenting the amount of dredged tonnes per unit area per year. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Estonia. The activity was declared as not relevant in Denmark, Germany, Finland, Latvia, Lithuania, Poland, Russia and Sweden. Attribute specification and units: Dredged_ar: Furcellaria dredging area (km2, ND = no data available) Area: Area (fishing area) within dredging occurs (km2), area do not represent actual dredging area. 2011 - 2015: Amount of dredged Furcellaria (tonnes / year) Total: Amount (Sum) of dredged Furcellaria during 2011-2015 (tonnes) Average: Calculated annual average of the amount of dredged Furcellaria (tonnes/year)

Input of impulsive anthropogenic sound includes impulsive events from 2011-2016 • Seismic surveys (HELCOM-OSPAR Registry; national data call submissions as lines in the folder of data) • Explosions (HELCOM-OSPAR Registry) • Pile driving (HELCOM-OSPAR Registry) • Airguns (HELCOM-OSPAR Registry) For the different event types, numeric intensity value was used to represent the pressure as categorized in HELCOM-OSPAR Impulsive noise registry. All nationally reported seismic surveys were given intensity values “Very low” (0.25) - Very low (0.25) - Low (0.5) - Medium (0.75) - High (1) The impact distance has not been taken into account due to the different nature of separate datasets used for the pressure layer. We acknowledge that e.g. pile driving and airguns may impact up to 20 km from the source event. The spread of the sound wave depends on the sound frequency, water salinity, temperature and density.

This dataset contains point data describing the location of oil platforms in the Baltic Sea. The dataset is complete in Baltic sea coverage as it contains two known oil platforms.

The dataset contains data on bridges and other constructions. The dataset is constructed from Open Street Map “roads” shapefiles downloaded through Geofabrik by extracting all features where attribute bridges=1. It should be noted that the dataset contains major bridges and all other smaller constructions that have been classified as bridges in Open Street Map. The coverage for the dataset is whole Baltic.