will be used as part of a project to stop salmon in California, US, taking a risky detour into "predatory-infested" waters.
The California Department of Water Resources (DWR) is concerned that Chinook salmon in the Sacramento River are leaving the main channel and taking a route into waters populated by striped bass and other predators, Central Valley Business Times reports.
Some 65 per cent of the salmon that enter Georgina Slough don't survive the trip.
To deter the fish, DWR will utilise acoustic fencing
and a bubble curtain that will operate at a frequency that will repel them.
The system has been used before, in the south Delta in 2009, and was judged effective. To test the efficacy of the Sacramento project, around 1,500 salmon will be tagged and monitored using sound receivers.
Also known as king salmon, Chinook are up to 28in in length and weigh up to 129lbs.