Odonata and Anthropogenic Salinization of Inland Waters

Abstract

The anthropogenic salinization of inland waters and its effect on freshwater biota are current environmental problems. This salinization leads to changes in the natural environment that are ecologically undesirable and not indifferent to humans. The widespread use of agents for road deicing has become one of the three most important factors of anthropogenic salinization of fresh water (along with agricultural activities and mining) in countries with temperate and cold climate. Today, the main components of these agents are Na and Ca chlorides—cheap and easily available natural materials. Their mixture with sand, used in deicing practice, is usually stored in bulk in special open-air areas all year round. The impact of atmospheric precipitation makes this mixture a source of salinization of the surrounding soils and waters. In 2015, 2016, and 2018, the salinity of inland waters was recorded near the long-term open storage of antiicing agents in Kaluga oblast. The anthropogenic nature of salinization of the investigated water bodies is established. The main components of salinization of water bodies in the study area are Na and Ca chlorides. The maximum degree of salinization in the studied conditions is 4‰ (ppm); the degree of salinity depends on the distance of the water body from the road-salt storage. The influence of anthropogenic salinity on dragonflies, mainly of the species Coenagrion puella L., is studied. It is found that the negative effect of high water salinity is expressed only in the slowdown of the development of individuals with a high level of fluctuating asymmetry, the number of which in the population is not determined by water salinity. High water salinity leads to changes only in the timing of emergence of imagoes with high FA. It is assumed that dragonflies as a mass object of freshwater biota are obviously not significantly exposed to anthropogenic salinization.