Poster Presentation International Conference on River Connectivity (Fish Passage 2018)

Fish migrations in the Volga River, Russia: Considerations for management of longitudinal connectivity (#219)

Konrad Górski 1 , Igor Askeyev 2 , Martin Schletterer 3
  1. Facultad de Ciencias y CIBAS, UCSC, Concepción, Chile
  2. The Institute of Problems in Ecology and Mineral Wealth, Tatarstan Academy of Sciences, Ka-zan , Russian Federation
  3. Department of Ecology, University of Innsbruck, Innsbruck, Austria

The Volga is the longest river in Europe and 16th longest in the world and it is of exceptional cultural and economic importance. A cascade of large, shallow reservoirs affects most of the hydrological regime of the Volga, from Tver (near Moscow) to Volgograd. The dams and their backwaters changed the appearance of the river and caused significant obstruction for migratory fish. Once iconic long distance anadromous migrants spawning in Upper Volga up to 3500 km from the delta e.g., Beluga, Starry Sturgeon or Caspian Trout practically disappeared from the river system and are on the verge of extinction. Nowadays, the three fish-passing structures that exist along the main river (two fish-sluice locks at the water divider in the delta, a hydraulic fish lift in the dam of the Volgograd Hydroelectric Power Station and a mechanical fish lift at the Saratov hydroelectric complex) are shut down and passage is only possible through ship locks. Overall multiple anthropogenic stressors impact migratory fish populations in the Volga basin e.g., hydromorphological alterations, pollution, invasive species as well as fisheries and poaching. Currently there is an extremely low level of control and management in the field of conservation of natural reproduction of fish and provision of migration. To restore longitudinal connectivity, it would be necessary to build and operate new fish-passing structures as well as ensure suitable habitats for spawning. A fish lift might be feasible to support migration if spawning habitats or lateral connectivity upstream are available. Natural bypass channels solutions may support migration as well as spawning grounds at the same time. Furthermore, it is also important to consider the descent of anadromous fish towards their feeding grounds in the Caspian Sea. Thus strategies also need to consider turbine passage as well as suitable downstream bypass structures.