Summary Estimated observations of the biotope AB.A1G3 and AB.M1G3 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic rock and boulders or mixed hard and soft substrates dominated by stone corals (Scleractinida)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 AB.A1G3and AB.M1G3according to HELCOM RED LIST assessment experts:The biotopes are restricted to the north Kattegat, where environmental conditions are nearly fully marine. The distribution map indicates the area in the 100 x 100 km grid where biotopes are known to occur. OCEANA (2013) encountered Carophylla smithii along the Swedish coast.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope 1620 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Boreal Baltic islets and small islandsThe 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 1620 according to HELCOM RED LIST assessment experts:The distribution map indicates the area in the 100 x 100 km grid where biotope is known to occur (Naturvårdverket 2011).(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AA.H1B4, AA.I1B4, AA.J1B4 and AA.M1B4 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic muddy or coarse sediment, sand or mixed substrate dominated by Charales 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.H1B4, AA.I1B4, AA.J1B4 andAA.M1B4according to HELCOM RED LIST assessment experts:The Charales biotopes are distributed along the whole Baltic Sea coastline. The biotope covers largeareas in the comparatively large, shallow and sheltered erman Bodden areas, the Polish and LithuanianLagoons, the Latvian Bay ofRiga and Estonian, and along the coasts of Finland and Sweden especially inflads. The higher the salinities, the higher the diversity of the biotope withrespect to accompanyingplant species and inhabiting invertebrate and fishcommunities. The diversity of Charales and relatedgenera can howeverincrease with decreasing salinity, as the charophytes are brackish andfreshwatermacrophytes. The distribution map indicates the area in the 100 x100 km grid where biotope is knownto occur.AA.H1B4, AA.I1B4, AA.J1B4 andAA.M1B4have 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 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.A1H2, AB.A1H2, AA.M1H2 and AB.M1H2 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 rock and boulders or mixed substrate dominated by erect moss animals (Flustra foliacea) 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.A1H2, AB.A1H2, AA.M1H2 andAB.M1H2according to HELCOM RED LIST assessment experts: The Flustra foliacea dominated biotope commonly occurs from Kattegat to the Mecklenburg Bight andArkona Basin (Kadetrinne). The spatial restriction to the Western Baltic Sea is due to the salinityrequirements of the dominant species Flustra foliacea. The more to the west or north-west this biotopeoccurs the higher the salinities, and in consequence the higher the diversity of inhabiting invertebrateand fish communities. The distribution map indicates the area in the 100 x 100 km grid where biotope isknown to occur, the occurrence of the biotope in the photic zone is restricted to the negative surfaces offor example boulders. AA.A1H2, AB.A1H2, AA.M1H2 and AB.M1H2 have 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 1180 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Submarine structures made by leaking gasesThe 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 1180 according to HELCOM RED LIST assessment experts:Shallow water examples of “bubbling reefs” colonised by macroalgae and/or animals are observed in Danish waters in the littoral and sublittoral zone from 0 to 30 m water depth. They are present in the northern Kattegat and in the Skagerrak and follow a NW SE direction parallel to the Fennoscandian fault line. Distribution map indicates the 10x10 km grid cells where the biotope complex is known to occur. More specific knowledge of the distribution of the biotope complex allowed its presentation on a higher resolution grid (Seffel 2010, EUNIS Database). If the occurrence had been presented in the 100x100 km grid used for the other biotope complexes, then the squares 11, 9, 20 and 18 had been indicated.(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 biotope AA.E1C4 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic photic shell gravel dominated by kelpThe 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.E1C4according to HELCOM RED LIST assessment experts:The kelp biotopes are common from Kattegat to the Bornholm Basin. The spatial restriction to the Western and Southern Baltic Sea is due to the salinity requirements of the dominant kelp species. The higher the salinities, the higher the diversity of the biotope with respect to accompanying plant species and inhabiting invertebrate and fish communities. The distribution map indicates the areas where the biotope can occur in a 100x100 km grid.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotopes AB.A1G2 and AB.M1G2 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic rock and boulders or mixed hard and soft substrates dominated by sea anemones (Actiniarida)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 AB.A1G2 and AB.M1G2 according to HELCOM RED LIST assessment experts:The biotopes occur on hard substrates in the Kattegat and Belt Sea. The biotopes are common on steep vertical cliffs and can also be encountered on the negative surfaces of rocks and overhangs. The distribution map indicates the area in the 100 x 100 km grid where biotopes are known to occur.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)

Summary Estimated observations of the biotope AB.A1F1 and AB.M1F1 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Baltic aphotic rock and boulders or mixed hard and soft substrates dominated by sea squirts (Ascidiacea)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 AB.A1F1 and AB.M1F1 according to HELCOM RED LIST assessment experts:The biotopes occur in the Kattegat and the Belt Sea. The distribution map indicates the area in the 100 x 100 km grid where biotopes are estimated to occur based on environmental gradients and the availability of the specific substrates.(Data (expert judgements) collected in HELCOM RED LIST project, released in May 2013)