Distribution of Zoobenthos in the Bottom Sediment of the Near-Shore Zone of the Baltic Sea in Nida–Klaipėda Stretch

Abstract

Distribution of sediment in the sea bottom of Nida–Klaipėda water area is determined by peculiarities of the bottom relief, hydrodynamic conditions, geological structure of shallow and nearshore zones. Sediment reflects the main features of sedimentation and biocenoses that are related to this process. While studying regularities of the distribution of the biocenoses of the sea ground fauna, abundance of animals and amount of biomass, a direct connection can be noticed with the granulometric composition of the bottom sediment and the depth. Coarser sediment of the bottom make optimum conditions for the development of zoobenthos. With the sediment getting finer and the depth decreasing, the biomass of some zoobenthic organisms also decreases (e.g. Macoma baltica), but the abundance of polychaetes (Pygospio elegans) notably increases. In the water area of the ground dumping, zoobenthic populations resistant to dumping of grounds are forming. Intensive bottom sedimentation with greater amounts of substrata m...