Fish Development in Lake Ecosystems, Effect of Heavy Metals

Abstract

Heavy metals enter the water bodies and combine with the water buffer system, then turn into poorly soluble hydroxides, carbonates, sulfides and phosphates, and also form metal-organic complexes, accumulate in the bottom sediments and in general in the bodies of the fish fauna of the reservoirs of the area, seriously affecting their development. It was determined that the amount of Ca2+ ions varied from 17 mg/l to 112 mg/l, and the amount of Mg2+ ions from 5.5 mg/l to 83.5 mg/l, in other words, towards autumn. water hardness has increased. The amount of alkali metal (Na+ + K+) ions is much lower in spring than in summer and autumn. According to the cations, the amount of chloride and sulfate ions increases in autumn. Thus, the impact of anthropogenic factors on fish is diverse and manifests itself primarily in morphological anomalies and changes in the basic biological parameters of fish populations. The main of them is the reduction of productivity and the complete loss of their natural forms, the increase of individuals and the increase of mortality.