An underwater acoustic system has been designed to protect fish from the turbines of a new hydro scheme at Beeston Weir, Nottingham, UK. The system generates a wall of sound at a frequency that repels fish and guides them past the turbines to the river below.

The acoustic fish screen consists of a series of underwater loud speakers. The sound is contained within a curtain of air bubbles creating a guiding wall along which the fish can swim through a specially designed fish pass, safely avoiding the turbines.

The fish deterrent, called a bio-acoustic fish fence, was developed by UK-based Fish Guidance Systems. Dave Lambert, the general manager, said: ‘This is the first time this type of technology has been used in the UK, and there has been a lot of interest in it across Europe and North America.’

The 80m long screen is part of a £3M hydro power project developed by Wales-based utility and renewable energy company, Hyder. Hyder’s hydro power business manager, Annie Thompsett, said: ‘It’s the equivalent of a classical music lover having pop music blaring out at them.’

The hydro power plant is expected to operate for at least 20 years and will generate 1.3MW of electricity, enough to power 2000 Nottingham homes. The project is backed by a Government Non-Fossil Fuel Obligation contract, which guarantees that the electricity produced will be bought at economic rates for 15 years.

Hyder, who will be opening the hydro power scheme in the spring, has worked closely with local organisations, including Nottingham City Council, English Heritage, the British Waterways Board, the Environment Agency, Nottingham Wildlife Trust, the Royal Society for the Protection of Birds and the Highways Agency, in order to protect the environment and ecology at Beeston Weir.