156 EUROPE/Holocene Figure 12 Enrichment of heavy metals within the last century, as recorded in a sediment core from the Arkona Basin (western Baltic Sea) (From Th Leipe, Baltic Sea Research Institute Warnemunde, with permission.) Figure 13 Trends of winter phosphate concentrations in the surface layer (0 10 m) of the eastern Gotland Basin (central Baltic Sea) (From G Nausch, Baltic Sea Research Institute Warnemunde, with permission.)