Comparative assessment of the content of transition metals (Cu, Zn, Mn, Pb, Cd) and radiocesium (137Cs) in pike (Esox lucius) and burbot (Lota lota) of the Yenisei River
T. A. Zotina1,2, O. V. Anishchenko1, E. A. Trofimova1, D. V. Dementyev1
1Institute of Biophysics, Federal Research Center “Krasnoyarsk Science Center” of SB RAS, Krasnoyarsk, Russia
2Institute of Fundamental Biology and Biotechnology, Siberian Federal University, Krasnoyarsk, Russia
Keywords: piscivorous fish, toxic metals, body length, body weight, size-effect
Abstract
Trophic position of fish is one of the most important factors controlling the accumulation of potentially toxic elements and compounds in fish tissues, primarily via the spectrum of fish nutrition. In this study, the content of potentially toxic transition metals (Cu, Zn, Mn, Pb, Cd) and radiocesium (137Cs) in the edible tissues (muscles and liver) of two representatives of the fish-eating ichthyofauna of the Yenisei River, northern pike ( Esox lucius ) and burbot ( Lota lota ), have been comparatively studied relatively to the size of the fish. A significant decrease in the content of radiocesium and zinc in the muscles of pike, and zinc in the liver of pike with an increase in body size was recorded in juvenile pikes with a body weight ( W ) of less than 0.35 kg. For larger sexually mature pikes, no significant size dependences of the accumulation of metals in tissues were found. A positive correlation was found between the content of 137Cs, Cu, Zn and Mn in muscles and the size of burbot in the W range from 0.42 to 1.62 kg. The tissues of one-sized burbots and pikes significantly ( p < 0.05) differed in the concentration of metals in their tissues: concentrations of Zn and Mn were 1.6-2.2 times higher in muscle of burbot; concentration of Pb was 1.8 times higher in muscle of pike; Cu was twice higher in liver of burbot; Zn and Mn were 4.7 and 1.6 times higher in liver of pike, respectively. The revealed differences may be due to the differing food spectra of pike and burbot. Concentrations of Cu, Zn, and Mn in liver of pike were 3-7 times higher than in muscle; concentration of Cu in liver of burbot was 5 times higher than in muscle. Pb and Cd tended to be higher in liver than muscle for both fish species. Despite the revealed size-dependences, the concentrations of potentially toxic metals and radiocesium in the muscles and liver of fish were below the permissible concentrations for food. The results obtained can be used to assess environmental risks for the population consuming fish, as well as to plan long-term environmental monitoring of rivers using representatives of fish-eating fish fauna.
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