EFFECT OF HEAVY METAL MODEL MIXTURE ON RAINBOW TROUT BIOLOGICAL PARAMETERS

Abstract

Studies of the acute and long-term toxicity of a heavy metal model mixture (HMMM) (based on real metal concentrations and proportion in soil near the Vilnius–Kaunas–Klaipėda highway on rainbow trout were performed using a set of biological parameters. The concentration of HMMM solution considered to be equal to 100% was for Cu 0.874; Zn 0.93; Pb 4.7; Ni 0.66; Cr 0.33; Mn 18 mg/l. The calculated 48-hour LC50 value for rainbow trout juveniles comprised 129.7%, and the 96-hour LC50 value 108.97% of HMMM solution. No significant changes were found in the weight of HMMM-exposed fish, while the liver weight of fish exposed to 21.79% of HMMM solution and the hepato-somatic index of fish exposed to 21.79 and 10.89% of HMMM solution differed significantly from control. Changes in blood parameters (erythrocyte count, haematocrit level, leukocyte count) revealed a specific HMMM toxicity to fish. Erythrocyte count decreased in the blood of fish exposed to all HMMM concentrations studied. Our data suggest that even low amounts of traffic emission pollutants can negatively affect the fish organism, causing various disturbances in its health and wellbeing.