The influence of sediments on soft bottom vegetation in inner coastal waters of Mecklenburg-Vorpommern (Germany)

The submersed aquatic vegetation, distinguished as nine different plant communities, was compared with sediment parameters (i.e. mean grain size, sorting level, silt fraction, lime and organic matter as well as content of total carbon, total nitrogen and total phosphorus) in four brackish lagoons in northeastern Germany (southern Baltic Sea). The sediment significantly influenced the distribution of plant communities in the coastal waters. Sorting level and exposition influence the radiation of Ruppia cirrhosa communities. Najas marina stands only grow on sediments with lower phosphorus content. Charophyte stands were found in sediments with smaller mean grain size and higher organic matter and nitrogen contents as plant communities associated with charophytes and without charophytes. However, the dependence of charophytes on low phosphorus levels – as observed in limnic waters – could not be verified in the coastal waters. No significant difference was found at different phosphorus levels between communities with and without charophytes. Myriophyllum spicatum–Potamogeton pectinatus communities – indicators of high degradation in the classification system of coastal waters – were present in a broad spectrum of sediment types, i.e. were not more abundant in habitats with nutrient-rich sediments and muddy sediments.