Summary The following 6 categories of annual mean salinity were applied delineating the Kattegat and the Baltic Sea into regions with differences in salinity regime (fig. 15): I. Oligohaline I (< 5psu). II. Oligohaline II (5 - 7.5psu). III. Mesohaline I (7.5 - 11psu). IV. Mesohaline II (11 - 18psu). V. Polyhaline (18 - 30psu). VI. Euhaline (>30psu). Description This dataset was produced by NERI, Denmark, for the BSR INTERREG IIIB project BALANCE. Due to the stratification in the Baltic Sea it was decided to use bottom salinity for the development of the benthic marine landscapes and difference in surface to bottom salinity for the pelagic landscapes. The following 6 categories of annual mean salinity were applied delineating the Kattegat and the Baltic Sea into regions with differences in salinity regime (fig. 15): I. Oligohaline I (< 5psu). II. Oligohaline II (5 - 7.5psu). III. Mesohaline I (7.5 - 11psu). IV. Mesohaline II (11 - 18psu). V. Polyhaline (18 - 30psu). VI. Euhaline (>30psu).

Summary This dataset shows model results for the average bottom temperature in the Baltic region in the plant growth season from April to September. Description This dataset shows model results for the average bottom temperature in the Baltic region in the plant growth season from April to September.

Summary Model results of the annual mean bottom current velocity (m/s). Description This dataset shows model results of the annual mean bottom current velocity (m/s). Data source, NERI/Denmark. Currents in the sea can be generated by many different parameters, among which are: I. Tidal motion II. Wind stress III. Density difference due to differences in salinity or temperature IV. Seismic activity and motion of the earth In near shore regions, the wave-induced along shore currents are the dominating currents, whereas in offshore regions, a combination of tidal and meteorological forces is the dominating current generating parameters. Near the sea bottom the friction of the current flow forms a turbulent layer, termed boundary layer, over the seabed. The thickness of this layer ranges from few meters up to several tens of meters. Within this layer the current speed increases nonlinearly with the height above the seabed, being zero at the seabed and maximum at the top of the layer. The variation of the current speed with height above the seabed is called current velocity profile.

The bathymetric model is created using data from the countries around the baltic sea. Sweden, Denmark, Finland and Estonia have all delivered data for this 500 meter grid model. Notice that this is modeled data, not actual measurements. The purpose of this database is to deliver a homogenous bathymetric model for the complete baltic sea at specfic resolutions. It is also important to notice that this data must not be used for navigation. Read the disclaimer for detailed terms and conditions. The model will be updated when new data is received from the participating countries. For further information about the complete metadata record see the original data provider metadata at: http://www.geodata.se/GeodataExplorer/GetMetaDataURL?url=http://www.geodata.se/geonetwork/srv/en/csw?request=GetRecordById!!!service=CSW!!!version=2.0.2!!!elementSetName=full!!!id=d3d4d136-46ca-4c00-a8e9-33a1d3bfb4d1!!!outputSchema=csw:IsoRecord

The data represents the seabed slope of the Baltic Sea and has been derived from a bathymetry dataset. Both datasets have been produced by the BSR INTERREG IIIB project BALANCE. For more information see also the metadata file on bathymetry.

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.

Raster grid of the Baltic Sea bathymetry computed with ArcGIS Spatial Analyst (KRIGING) from the original Digital Topography of the Baltic Sea (IOWTOPO) database produced by the Baltic Sea Research Institute of Warnemunde. Output resolution of the grid is 250 m, data is projected into ERTS89_LAEA CRS (Lambert Azimuthal Equal Area projection, ETRS89 datum), file format is Erdas Imagine (IMG), data format is continuous, float.

Summary This marine benthic landscape map of the Baltic Sea includes 60 broad scale habitat types which are defined according to different combinations of bottom substrate, photic zone and salinty level. Description This dataset was produced by the EU funded Balance project and maps the ecologically relevant benthic landscapes (broad-scale benthic habitats) of the Baltic Sea, identified on salinity, sediments and photic depth (as light touching the seabed). This marine benthic landscape map of the Baltic Sea includes 60 broad scale habitat types which are defined according to different combinations of bottom substrate, photic zone and salinty level. Each habitat is described with a three digit grid code, where the first digit refers to bottom substrate, the second digit refers to photic zone and the third refers to salinity. Description of grid code digits: Bottom substrate: 1= bedrock, 2 = hard bottom, 3 = sand, 4 = hard clay, 5 = mud Photic zone: 1 = photic, 2 = aphotic Salinity: 1 = 0-5 psu, 2 = 5 - 7.5 psu, 3 = 7.5 -11 psu, 4 = 11 - 18 psu, 5 = 18-30 psu, 6 = <30 psu The approach to marine landscape mapping within the Baltic Sea is based on the use of available physical, chemical and hydrographic data to prepare ecologically meaningful maps for areas with little or no biological information. It is basically a broad-scale map-ping/modelling approach based on presenting geophysical and hydrographical data in thematic GIS layers from which “marine landscapes” can be derived. In order to limit the number of possible landscapes the thematic layers are typically presented in a lim-ited number of categories reflecting shifts in major ecological entities (e.g. distinguish between habitats assumed to be within or below the photic zone). The approach aims to recognise the ecological linkage between major assemblages of species and the physical environment in which they reside. It can be applied to charac-terising broad-scale benthic complexity using parameters such as surface sediment, temperature, water motion, photic depth and slope and for semi-enclosed areas, like the Baltic Sea, salinity and oxygen content.Due to the limited resolution of the dataset, it should be only used for broadscale purposes. The dataset also requires verifications. (The quality of data collated differs from high to low-resolution data. Some of the modelled datasets has 7km resolution while others have ~600m resolution. All datasets were re-gridded to a 200 × 200m grid. This process ensures data continuity but it does not increase the out-put map resolution.)

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