Broad-scale habitat maps for the Baltic Sea have been produced in the EUSeaMap project in 2016. For German and Estonian marine areas, national (more accurate) datasets were used. German data included both substrate and light information (division into infralittoral/circalittoral). Estonian data included only substrate and the division into light regimes was obtained from the EuSeaMap data. Here, the habitat class “circalittoral hard substrate” includes classes “Rock and other hard substrate” and “Coarse substrate” of the original data, in the circalittoral zone. The original polygon maps have been converted to 1 km x 1 km grid. The scale of the substrate data used in broad-scale habitat maps varies from 1:250 000 to 1:1M (data from EMODnet Geology). Coarser resolution data has been used in areas, where 1: 250 000 substrate data has not been available. Due to different scales used, the habitat classes may show different sized patterns in different areas.

The occurrence of suitable nursery habitats is crucial for maintaining fish populations (Sundblad et al. 2013). Species distribution modelling studies have shown the importance of suitable environmental conditions for pikeperch recruitment. Due to lack of coherent data on pikeperch spawning and nursery areas across the Baltic Sea countries, environmental variables were used in delineating potential recruitment areas for pikeperch. The pikeperch recruitment area presented on the map is mainly delineated by selecting areas where depth < 5 m, logged exposure < 5, salinity < 7 PSU, Secchi depth < 2 m and distance to deep (10m) water < 4km. The threshold values have been obtained from literature (Veneranta et al. 2011, Bergström et al. 2013, Sundblad et al. 2013, Kallasvuo et al. 2016). Temperature, although important for pikeperch, was left out due to high variation in timing of suitable spawning temperatures across the Baltic Sea. In Finnish coastal waters, a national pikeperch model (Kallasvuo et al. 2016) has been used, with very suitable areas for pikeperch generalized to 1 km grid. In Sweden, the areas delineated by environmental variables have been complemented with information from national interview survey (Gunnartz et al. 2011) as well as expert opinion.

Number of hunted cormorants (Phalacrocorax carbo) per year per county. A total sum and a calculated average (hunted individuals / year) is given for the time period 2011-2015. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Denmark, Estonia, Finland and Sweden. The activity was declared as not relevant in Germany, Lithuania and Poland. From Latvia and Russia no data was reported. Attribute specification and units: Country: Country County: County SUM: Total number of hunted individuals during 2011 – 2015 AVERAGE: A calculated five (or four) year average of hunted cormorants per year (hunted individuals/year) 2011 – 2015: Number of hunted cormorants in the year in question

The amount of collected mussels with dredging. Data is presented from the Danish mussel areas within the HELCOM marine areas. The data was made available by HELCOM Contracting Parties in response to data request. The data was received from Denmark. The activity was declared as not relevant in Estonia, Finland, Latvia, Lithuania, Poland, Russia and Sweden. Germany indicated that data is not available. Attribute specification and units: Nr: Identification number of the mussel area Name: Name of the mussel area BluMusl05 – BluMusl15: Amount of Blue mussel (kg) collected per year ComCockl05 – ComCockl15: Amount of Common Cockle (kg) collected per year Sum_BMus: Total amount of collected Blue mussel in 2005 to 2015 (kg) AVG_BMus: A calculated average of the collected blue mussels in 2005 – 2015 (kg/year) AVG_2_BM: A calculated average of the collected blue mussels in HOLAS2 period 2011 – 2015 (kg/year) Sum_ComC: Total amount of the collected common cockles in 2005 – 2015 (kg) AVG_ComC: a calculated average of the collected common cockles in 2005 – 2015 (kg/year) AVG_2_ComC: A calculated average of the collected common cockles in HOLAS2 period 2011 – 2015 (kg/year) Area: The mussel area within the dredging occurs (km2)

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

Mudflats and sandflats not covered by seawater at low tide (according to Habitats Directive Annex I) are often devoid of vascular plants, usually coated by blue algae and diatoms. They are of particular importance as feeding grounds for wildfowl and waders. The distribution map is based on data submission by HELCOM contracting parties. Only Denmark, Germany and Estonia reported occurrences of mudflats and sandflats. Most of the submitted data is based on modelling and/or GIS analysis. Data coverage, accuracy and the methods in obtaining the data vary between countries.

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

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

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

Regional hunting numbers for Grey seals 2011-2014.