Results of a comprehensive study of water bioresources of lake Senezh

Abstract

In the paper, preliminary results of hydrochemical, hydrobiological, parasitological and ichthyological investigations have been given, carried out on waters of the Lake Senezh in 2020 and compared with analogous works for 2004–2006. The ecosystem of the given water object is extremely understudied. In the size structure of fish species, caught in 2020, dynamics of a good reproduction potential could be noted. The condition factor of all fish species is very high. One can see a significant prevalence of females over males, excepting bream, in all fish groups studied. The water object investigated showed the 2,8 times MPC increase for iron in fish farming water bodies. Concentration of toxic elements in water samples and bottom sediments did not increase MPC for all other indices. The bacteriological water analysis showed insignificant increase of bacterial contamination at the area of the investigation station 6 only, what is most likely of the anthropogenic nature and is being a result of the littoral lake zone pollution. Parasitological analysis of the Senezh lake fishes indicates of o high level of their invasion. 11 parasites species were found in 3 fish species investigated, which were represented by 73% of trematodes at the metacercaria and maritas stage. The fish ergasiles problem, existed in this water body since 2005 and up to-date, continues. In zanders gills, parasitic Ergasilus sieboldin were found. The given work would be interesting for investigators who will study the Senezh lake as well as other water bodies of the Moscow area.