Summary Estimated observations of the biotope AA.H3L6 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic muddy sediment dominated by UnionidaeThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.H3L6according to HELCOM RED LIST assessment experts:The biotope is known to occur in the eastern parts of the Curonian lagoon in Lithuania. Mussel species of the family Unionidae occur in the whole Baltic Sea region and can occur in densities high enough to be habitat forming in estuaries. The distribution map indicates the area in the 100 x 100 km grid where biotope is known to occur.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope 1150 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Coastal lagoonsThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of the biotope 1150 according to HELCOM RED LIST assessment experts:Lagoons are a typical feature of the dynamic Baltic Sea coast and occur or occurred in the past in all HELCOM sub-regions.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AA.H1B7, AA.I1B7, AA.J1B7 and AA.M1B7 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic muddy sediment, coarse sediment, sand or mixed substrate dominated by common eelgrass (Zostera marina) The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea. Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.H1B7, AA.I1B7, AA.J1B7 andAA.M1B7according to HELCOM RED LIST assessment experts: The Zostera beds are common from Kattegat to the Archipelago Sea in the northern Baltic, and thesalinity gradient from south to north causesconsiderable differences to the composition of theassociated fauna and flora.In the southern Baltic Sea the eelgrass usually forms pure stands along theouter, exposed coastline, whereas in the northern part of the Baltic Sea and insouthern bays andlagoons it often grows intermixed with other aquaticangiosperms. The largest occurrences of thebiotopes dominated by Zosteramarina are found in the southern Baltic Sea, where they represent oneof themost abundant biotopes of the sublittoral. The distribution map indicates thearea in the 100 x 100 kmgrid where biotope is known to occur based on field sampling data. AA.H1B7, AA.I1B7, AA.J1B7 andAA.M1B7have been placed in the Red List classification to the category of Near Threatened (NT) biotopes. (Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope 1130 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Estuaries The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of the biotope 1130 according to HELCOM RED LIST assessment experts:Estuaries are present in the entire Baltic Sea area. Examples of river mouth areas in Denmark: Gudenåen-Randers Fjord, Horsens Fjord, Vejle Fjord, Kolding Fjord Sweden: Bräkneån, Hagbyån, Virån, Loftaån, Finland: Porvoonjoki river mouth area, Kymijoki river mouth area, Merikarvianjoki, Aurajoki river mouth area, Russia: Neva estuary, Germany: Trave estuary, Warnow estuary, Peene mouth area. The known occurrences of the estuary biotope complex in a 100x100 km grid (Naturvårdverket 2011, EUNIS Database, HELCOM 1998)(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope 1110 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Sandbanks which are slightly covered by sea water all the timeThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of the biotope 1110 according to HELCOM RED LIST assessment experts:Sandbanks are widely spread throughout the whole Baltic Sea area, and occur in all HELCOM sub-regions. The Distribution map indicates the area in the 100 x 100 km grid where biotope is known to occur (Naturvårdverket 2011, EUNIS Database).(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AA.I3L10, AA.J3L10, AB.I3L10 and AB.J3L10 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic or aphotic coarse sediment or sand dominated by multiple infaunal bivalve species: Macoma calcarea, Mya truncata, Astarte spp., Spisula spp. The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.I3L10, AA.J3L10, AB.I3L10 andAB.J3L10according to HELCOM RED LIST assessment experts:Kiel bight to Isle of Fehmarn, might occasionally occur in Mecklenburg Bight to Darss sill, South-westernBaltic Sea. The distribution map indicates the area in the 100 x 100 km grid where biotope is known tooccur.AA.I3L10, AA.J3L10, AB.I3L10 andAB.J3L10have been placed in the Red List classification to the category of Near Threatened (NT) biotopes. (Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotopes AA.D and AB.D were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic and aphotic maërl beds (unattached particles of coralline red algae)The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.Dand AB.Daccording to HELCOM RED LIST assessment experts:Known areas where maërl beds occur are on offshore banks in the Kattegat (e.g. Lilla Middelgrund and Fladen). The presence of dead maërl at some offshore banks indicates that the habitat must have been more widespread in the past. It is unclear how large a proportion of the maërl beds occur in the aphotic zone. Maërl beds have a patchy distribution. The distribution map indicates the area in the 100 x 100 km grid where maërl beds are known to occur.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AB.H4U1 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic muddy sediment dominated by meiofaunaThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AB.H4U1 according to HELCOM RED LIST assessment experts:The biotope is assumed to occur throughout the Baltic Sea both in shallow coastal waters and in the deeper central parts of the sea. The distribution map indicates the area in the 100 x 100 km grid where biotope is reported to occur. The biotope may have a significantly wider distribution.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AA.H1A2 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic muddy sediment dominated by sedges (Cyperaceae)The HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.H1A2 according to HELCOM RED LIST assessment experts:The muddy sedge biotope can be found in very sheltered lagoons and in some estuaries around the whole Baltic Sea however the main distribution of the biotope along the coast of the Baltic Sea is in the northern parts. The distribution map indicates the area in the 100 x 100 km grid where biotope is estimated to occur.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AA.H3L6 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic muddy sediment dominated by UnionidaeThe HELCOM Red List of Baltic Sea underwater biotopes, habitats and biotope complexes (2013) is an updated and improved version of the Red List assessment of marine and coastal biotopes and biotope complexes published in 1998. The classification of the report follows the proposed International Union for Conservation of Nature (IUCN) criteria and assessment principals but with some modifications for the Baltic Sea.Altogether, the HELCOM Underwater Biotope and habitat classification (HELCOM HUB) includes 209 biotopes of which 59 were red-listed. Many of the red-listed biotopes are located in deep areas of the Baltic Sea due to oxygen-free nature as well as in the southwestern Baltic Sea due to the salinity restricted distribution of species in certain biotope. The HELCOM assessment relies heavily on expert judgment and inference, and the questionnaire data represents the estimated presence-absence data not in-situ measured data. This must be taken in account when observing the map presentation. The biotopes are shown on the map using the EEA 100 km grid. This dataset displays estimated presence of AA.H3L6according to HELCOM RED LIST assessment experts:The biotope is known to occur in the eastern parts of the Curonian lagoon in Lithuania. Mussel species of the family Unionidae occur in the whole Baltic Sea region and can occur in densities high enough to be habitat forming in estuaries. The distribution map indicates the area in the 100 x 100 km grid where biotope is known to occur.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)