Fish screen

A fish repelling system serves to keep the living within a body of water fish from a particular area where they are not wanted or there is a risk for them.

Electric fish shyness Chung

An electric fish repelling system produced by submerged into the water electrodes creating an electrical field pulse - the streamer field - that is to scare away fish. These pulses in the millisecond range with randomly alternating sequence and frequency are generated ( against the effects of habituation ) and a current density of at least 2.56 uA per square millimeter of water cross section. The body of a fish which is located in the streamer array is traversed by the current which thus acts on the fish. The current is applied so that it preferably flows along the flow direction of the water. As put fish in general along the flow, the flow a longer distance through the body of the fish and the effect thus flows is stronger. At high flow rates, the plants are no longer effective, which is why she / s are allowed in Germany only at flow rates of less than 0.3 m. The investments will be warned ( in Germany ) with warning signs of the danger of electric shock.

Such systems are, for example, used at the inflow to water turbines or the cooling water intake of power plants.

In addition, acoustic tickler systems were in the hydraulic laboratory Schleusingen the Bauhaus- University Weimar, funded by the German Federal Environmental Foundation, tested.