Communities of Benthos Invertebrates of the Kiliya Delta of the Danube River

Abstract

The communities of benthos invertebrates occurring in various biotopes of the water bodies, watercourses, and coastal zone of the Kiliya delta of the Danube River were distinguished based on the similarity of their species composition. It has been found that mainly water salinity is responsible for the formation of their physiognomy and hierarchic organization in the Kiliya delta of the Danube River, whereas the types of bottom sediments and the types of water bodies are responsible for the formation of their components. The levels of hierarchic organization of benthos communities are as follows: the lowest level is formed by primary mosaic communities occurring in various water bodies and on various types of bottom sediments, the next level is formed by the united communities distributed on various types of bottom sediments in fresh or brackish water bodies, whereas the highest level is formed by the communities of the Kiliya branch and the Danube River delta on the whole. It has been shown that the discreteness and continuality of benthos communities in the Kiliya delta of the Danube River are formed due to the development of both fresh and brackish species.