Summary Model results for the distribution of where at least 1% available light touches the seabed (the photic zone) and non-photic zone in the Baltic Sea based on 1% mean annual irradiance Description This dataset shows model results forthe distribution of where at least 1% available light touches the seabed (the photic zone) and non-photic zone in the Baltic Sea based on 1% mean annual irradiance. From an ecological point of view, available light is one of the primary physical parameters influencing and structuring the biological communities in the marine environment, as it is the driving force behind the primary production by providing the energy for the photosynthesis - energy that ultimately is transferred to other organisms not capable of photosynthesis. The depth of the photic zone is traditionally defined, for benthic plants, as the depth where 1% of the surface irradiance (as measured just below the water surface) is available for photosynthesis. Only two intervals based on light regime were used in the dataset, because they reflect the significant ecological difference between the shallow water depth with the presence of submerged aquatic vegetation, and the deeper waters where fauna (and bacteria) dominate diversity of species, abundance, and biomass. The intervals are: I. The photic zone (where at least 1% of the available light touches the seabed). II. The non-photic zone.The measurements of Secchi Depth used for producing this dataset are not evenly distributed and some areas in the Baltic Proper, Gulf of Riga and southern Baltic are not well covered.

Summary Marine seabed sediment split into 5 categories in the Kattegat and Baltic Sea (compiled from sediment information from GEUS, GSF and SGU). Description Marine seabed sediment split into 5 categories in the Kattegat and Baltic Sea (compiled from sediment information from GEUS, GSF and SGU). The sediment composition of the seabed is considered essential in marine landscape production as it is one of the primary parameters influencing the biogeographic distribution of marine benthic species and a primary component in shaping the physical structure and function of marine habitats. The resulting classification scheme consists of five sediment classes, which can be extracted from existing data. The sediment classes applied in the mapping and modelling of the Baltic Sea marine landscapes are: I. Bedrock. II. Hard bottom complex, includes patchy hard surfaces and coarse sand (sometimes also clay) to boulders. III. Sand including fine to coarse sand (with gravel exposures). IV. Hard clay sometimes/often/possibly exposed or covered with a thin layer of sand/gravel. V. Mud including gyttja-clay to gyttja-silt. For more details see: BALANCE Interim Report no. 10 "Towards marine landscapes in the Baltic Sea": http://balance-eu.org/xpdf/balance-interim-report-no-10.pdf