Abstract
It is ascertained by the results of measurements of intensity of electric fields under above-water passages of power lines in the water environment that the values of intensity of electric fields 50 Hz under power lines of 100 and 220 kV belong to the microvoltage range. By comparative analysis of the intensity levels of fields under power lines with thresholds of electric sensitivity of freshwater fish, it is shown that the electric fields of such levels may influence orientation and behavior of fish characterized by a high electrosensitivity.