Long-term changes in the vertical distribution of macrophytobenthic communities in the Greifswalder Bodden

Abstract

Species diversity among the submerged vegetation of Greifswalder Bodden (Southern Baltic, Island of Rűgen, Germany), which exhibits a distinct vertical zonation, is low. The vegetation grows at depths down to 3-4 m. Corresponding to the depth variations, aerial photographs show up to 3% of the bottom to have a plant canopy. Distribution of the phytal fauna depends greatly on the structure of the different plant species, the life cycles of both plants and animals, and on movements of the water and sediment. The literature reports plants growing at depths down to 8 m 50 years ago, over 90% of the bottom having a plant canopy then. The magnitude and ecological consequences of the drastic loss of vegetation due to eutrophication are discussed.