Dynamics and Structural Changes of the Fluke Fauna in Fish of the Volga Delta Caused by the Rise of Water Level in the Caspian Sea

Changes in the Caspian Sea level and anthropogenic influences on biocenoses of the Volga Delta periodically result in the changes of dominant species among animal helminths. An abrupt rise of the sea level since the mid-1970s caused structural rearrangements in the fluke fauna of fish in the 1990s: the species whose development is connected with mollusks of the rheophilic complex became dominant.