This dataset contains all PAH in sediment monitoring station locationsas reported to HELCOM secretariat by HELCOM Contracting Parties by 2016.

This dataset contains all TBT in biota monitoring station locations, observed matrix, biota matrix and monitored species as reported to HELCOM secretariat by HELCOM Contracting Parties by 2016.

Regional hunting numbers for Harbour seals 2011-2014.

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)

This dataset contains all PCB in biota monitoring station locations, observed matrix, biota matrix and monitored species as reported to HELCOM secretariat by HELCOM Contracting Parties by 2016.

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)

Springtime Chl-a concentration is here used as a proxy for productive surface waters. In the Baltic Sea Impact Index (BSII), 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, years 2003-2011) Chl-a concentration of the surface waters has been used, derived from satellite data (MERIS). Years 2003-2011 have been used, as there is no MERIS data available for years 2012-2016. The data for eastern Baltic Sea is provided by the Finnish Environment Institute (~300m resolution). Outside this high resolution data, MERIS-data downloaded from JRC-database has been used (~4 km resolution, to calculate average of maximum monthly values for April or May for 2003-2011). Both datasets were converted to 1 km x 1 km grid cells.

Location of water course modifications (trenching, culverting, canalisation). The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Estonia, Finland and Poland. Data reported by Finland and Poland as water course modification were interpreted as pipelines and were included in HELCOM HOLAS 2 Pipelines dataset. The activity was declared as not relevant in Germany and Lithuania. From Latvia, Russia and Sweden no data was reported.

Introduction of radionuclides is based on HELCOM MORS Discharge data from 2011 to 2014. The isotopes taken into account were: Cesium-137, Strontium-90, and Cobalt-60. The decay-corrected annual average of the sum of the radionuclide discharges (in Bq) were calculated for the pressure. 10 km buffer with linear decreasing function was used to represent the impact distance from the nuclear power plant outlets.

This dataset is built from the following Human activities dataset: • Hunting of seals The number of hunted seals (see separate metadata on hunting of seals) were averaged over 2011-2014 separately for grey seals, ringed seals and harbour seals (e.g. number of hunted grey seals / year). In Sweden the numbers of hunted grey seals in 2011 (74) were reported for the whole Swedish territorial waters), but here the numbers were set only to Swedish Gulf of Bothnia, as corresponding numbers were reported there in 2013 (75) and 2014 (65). The area of the reporting unit was used to calculate the number of hunted seals / km2 and the data was converted to 1km x 1km grid. For the Baltic Sea Impact Index, the values were normalized. Normalized value 0.5 was set to the level of quota for hunting of seal species in the Baltic Sea. The following quotas for hunting were used: Grey seal: 2000, Ringed seal: 350, Harbour seal 230.