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 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 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)

Summary Estimated observations of the biotope AA.I3L11, AB.I3L11, AA.J3L11 and AB.J3L11 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 dominated by multiple infaunal polychaete species including Ophelia spp Baltic photic or aphotic sand dominated by multiple infaunal polychaete species including Ophelia spp. and Travisia forbesii 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.I3L11, AB.I3L11, AA.J3L11 andAB.J3L11according to HELCOM RED LIST assessment experts: The biotope occurs mainly in the southern and western parts of the Baltic Sea area, but is very rare. They are found in exposed abrasion areas (sandbanks, near-shore wave exposed shallow sublittoral). Kiel bight to Darss sill. The distribution map indicates the area in the 100 x 100 km grid where biotope is known to occur. AA.I3L11, AB.I3L11, AA.J3L11 andAB.J3L11have 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 1650 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Boreal Baltic narrow inletsThe 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 1650 according to HELCOM RED LIST assessment experts:Fjords are present in Swedish and Finnish coastal areas of the Bothnian Sea, the Gulf of Finland and the Baltic Proper. The present and past distribution is in areas of crystalline bedrock. 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 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.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 biotope 1140 were collected from the Baltic Sea area by expert judgements for HELCOM Red List of biotopes, habitats and biotope complexes. Description Mudflats and sandflats not covered by seawater at low tideThe 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 1140 according to HELCOM RED LIST assessment experts:Mudflats and sandflats not covered by sea water at low tide occur in all parts of the Baltic Sea area, but patterns and descriptions of their distribution are mostly missing. In the Lahemaa area (Southern Gulf of Finland) for example, they are representing 3% of all habitats and also in the German Baltic Sea region they form a very narrow strip along some the coastlines. No information is available on their historical distribution. 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.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)