Survey of spawning areas of the Upper Reach of the Tsimlyansk Reservoir

 

The objective of the cruise was to survey the most important spawning areas of the Upper Reach of the Tsimlyansk Reservoir, collect hydrochemical and hydrobiological samples, and assess the effectiveness of natural reproduction of aquatic biological resources.

 

The scientific group surveyed 4 trawl catches and carried out work on 22 spawning areas using a fry drag. The samples of fry were sorted by species at the fishing site, their number was determined per spot and per unit area.

 

The Upper Reach of the Tsimlyansk Reservoir differs from the lower reaches in that the river regime has been almost completely preserved here: throughout the year, there is a constant current and slope of the water surface, which increases during the flood. It is in this part of the reservoir, along its left bank, that a vast floodplain of 80-100 km in length with many lakes, channels and bays has been preserved in a slightly changed form, where, during spring flooding, fairly large areas are created from 6.6 in low-water years to 17.0 thousand hectares in high-water years, well-warmed shallow water.

 

The floodplain areas of the Upper Reach are the most productive natural spawning grounds, as evidenced by the catches of the fry drag showing that the concentration of young valuable commercial species here is 64% of the total catches in all reaches.

 

Press service of VNIRO