the purpose of the research was to develop a mobile fish protection device that increases the efficiency of protection of ameliorative water intake devices from the ingress and death of juveniles and larvae of fish by providing uniform pressure on hydrobionts created by a volumetric countercurrent along the living section of the prismatic channel of the water intake by a mobile fish protection device. device. Field studies were carried out at the water intake facilities of Rassvet LLC, Kurganinsky District, and Soyuz Agro LLC, Gulkevichsky District, Krasnodar Territory, as part of the irrigation system during the growing season of agricultural crops. Production experiments were carried out in areas of small watercourses - the Sinyukha River and the Novokuban Canal, flowing through the territory of the Krasnodar Territory. It has been established that an increase in the efficiency of fish protection is achieved by the fact that a mobile fish protection device installed in front of the intake window and consisting of a collector with water jet nozzles to create a volumetric hydraulic screen and flow-forming elements that create a counterflow directed towards the intake flow with speeds , exceeding the speed of the approach flow, ensure the diversion of fish from the water intake area to the safe area of the water source. The fish protection structure has an autonomous water purification and supply system containing a water chamber for water, a filter for its mechanical cleaning and a pump with a drive connected in series with each other, connected with a collector with water intake windows installed on it, depending on the size and shape of the water intake window in a checkerboard pattern water jets. The research results show the increase in the efficiency of the mobile fish protection device is in the range of 84-90 % depending on the pressure, the number of nozzles and the angle of inclination of the flow generator.