Use constraints: Free for non-commercial purposes. Reference to source (NERI, BALANCE) must be given.

The comprehensive analysis of the salinity distribution within the Skagerrak, Kattegat and Baltic Sea was made on salinity data from an extensive number of field stations ranging from the Bothnian Bay to the Baltic Proper including the Gulf of Finland and the Bay of Riga. Data was also included from stations in the German Bight, Danish Straits, Kattegat and Skagerrak. The depth and spatial location of the stations used to collate data for the model. These provided the input to a threedimensional primitive equation model based on the COHERENS model (Luyten et al. 1999), which was used for quantifying transports and distributions of salinity, temperature and additional tracers. For more detailed information on the origin of data and description of the model, please refer to Bendtsen et al. (2007). This analysis provided the description of the bottom (and surface) salinity conditions in the Baltic Sea.

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).

In order to be displayed in the HELCOM Map Service, the map coordinate system and projection was changed from original WGS1984_UTM34N to ETRS_1989_LAEA.

For more information about this dataset see BALANCE Interim Report no. 10 "Towards marine landscapes in the Baltic Sea": http://balance-eu.org/xpdf/balance-interim-report-no-10.pdf.

For details on the model and the data sources, please refer to Bendtsen, J., Söderkvist, J., Dahl, K., Hansen, J.L.S. & Reker, J. (2007): Model simulations of blue corridors in the Baltic Sea. BALANCE Interim Report no. 9. Available at http://balance-eu.org/xpdf/balance-interim-report-no-9.pdf.