Comparative analysis of the species composition of ichthyofauna of fish watering holes and adjacent channel areas of the Krasnoyarsk fl oodplain of the Volgograd reservoir

Abstract

The Volgograd reservoir is a highly complex hydrological system. The locations of fi sh watering holes, which are situated in an abyssal area of the Volgograd reservoir, have been well established for a long time. Meanwhile, fi sh watering holes exist in areas of the bed of the Volgograd reservoir as well. However, their determination is not always possible and is complicated due to the small size and shallow depth of the watering holes. The aim of this work was to carry out a comparative analysis of the species composition of fi sh caught in watering holes and adjacent channel areas. The results might fi nd an application in fi sh farming. The studies were conducted in the 2019–2020 winter season within Krasnoyarsk fl oodplain of the Volgograd reservoir. Floodplain length stretches some 26 km. The width of the Krasnoyarsk fl oodplain is 4–10 km. The depth of the Krasnoyarsk fl oodplain ranges from 0.1 to 10 meters. A bathymetric survey was conducted in order to validate data concerning the depths of fi sh watering holes. The current changes its direction periodically within the fl oodplain as a result of water passing by Saratov and Volgograd hydraulic structures, thus infl uencing the relief of the reservoir bed due to various locations of fi sh watering holes. The evaluation of the species composition of ichtyocoenosis was conducted using test fi sheries and assessment of fi sh caught by recreational fi shers. We assessed 19 fi sh species in the Krasnoyarsk fl oodplain of the Volgograd reservoir during the winter season using all fi shing techniques. The conducted analysis of the Shannon diversity index within the watering holes and adjacent areas allows confi rmation that all of the studied holes are active and serve as fi sh gathering places during the winter period. This study will allow the development of recommendations for the confi rmation or revision of the status of fi sh watering holes in any subsequent study of bodies of water. That will facilitate the preservation of fi sh resources. 

Keywords

• fi sh watering holes
• ichtyocoenosis
• species composition
• the volgograd reservoir