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 “infralittoral mud” includes classes “Fine mud”, “Mud to sandy mud” and “Sandy mud” of the original data, in the infralittoral zone. The original polygon maps have been converted to 1 km x 1km 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.

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

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 represents the radioactive discharges from nuclear facilities in the Baltic Sea area. Data includes isotopes CS137, CO60 and SR90 Aquatic discharges in 2011-2014 with decay corrections.

The shipping density map highlights the intensity of all IMO registered ships operating in the Baltic Sea. It is based on the HELCOM AIS (Automatic Identification System) data. The HELCOM AIS dataset contains all the AIS signals received by the Baltic Sea States since 2005. The data was pre-processed by the HELCOM Secretariat (under the Baltic SCOPE project) in order to have a dataset that could be used to generate products such as density maps and traffic statistics.

The occurrence of suitable nursery habitats is crucial for maintaining fish populations (Sundblad et al. 2013). For perch, species distribution modelling studies (Snickars et al. 2010, Bergström et al. 2013, Sundblad et al. 2013) have shown the importance of suitable environmental conditions for reproduction. Due to lack of coherent data on perch spawning and nursery areas across the Baltic Sea countries, environmental variables were used in delineating potential recruitment areas for perch. The distribution area or perch recruitment is delineated by selecting areas where depth < 4 m (For Danish waters < 3 m), logged exposure < 5 (exposure model described in Isæus 2004), and salinity < 10 PSU. The threshold values have been obtained from literature (Snickars et al. 2010, Bergström et al. 2013, Skovrind et al. 2013, Sundblad et al. 2013). Relatively “loose” thresholds have been used, to rather overestimate than underestimate the recruitment area (precautionary approach). Along the Finnish coastline a national model has been used (Kallasvuo et al. 2016), with suitable environments for perch recruitment generalized to 1 km x 1 km grid.

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 sediments monitoring station locationsas reported to HELCOM secretariat by HELCOM Contracting Parties by 2016.

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