The Baltic Sea is one of the largest brackish water bodies in the world (Segerstråle 1957) with a number of basins varying from almost fresh water in the northern part of the Bothnian Bay via the more brackish conditions in the southern part to the saline waters of the Kattegat. The Baltic Sea is subject to severe environmental degradation caused by commercial and leisure activities, including fisheries, dredging, tourism, coas t a l development and land-based pollution sources. This causes severe pressures on vulnerable marine habitats and natural re- sources, and a tool for aiding marine management is therefore strongly needed. The marine landscape concept presented by Roff &Taylor (2000) is based on the use of available broad-scale geological, physical and hydrographical data to prepare ecologically meaningful maps for areas with little or no biological information. The concept, which was elaborated by Day & Roff (2000) was applied in UK waters (Connor et al. 2006) before it was adopted by the BALANCE project described here. The aim of developing marine landscape maps is to characterise the marine environment of the Baltic Sea region (the Baltic Sea together with the Kattegat) using geophysical and hydrographical parameters. Such maps can be applied, for example, to an assessment of the Baltic-wide network of marine protected areas, and thus provide a sustainable ecosystem-based approach to the protection of the marine environment from human activities, and contribute to the conservation of marine biodiversity. The BALANCE project is based on transnational and cross-sectoral co-operation with participants from nine countries surrounding the Baltic Sea as well as Norway (Fig. 1), and is partially financed by the European Union through the BSR INTERREG IIIB programme.
Rapid speciation in a newly opened postglacial marine environment, the Baltic Sea
