To determine how well fish pass through hydroelectric power plants, an international research team is developing electronic fish to test in place of live fish, according to a new study.

Called RETERO (Reducing animal testing to establish risk of injury to fish caused by passage through turbines by the use of robotic surrogates, computational fluid mechanics and predictive modeling), the project will attempt to develop partially autonomous robot systems and simulation models aimed at reducing and eventually eliminating live fish animal experiments.

The team of researchers from the University of Magdeburg, the Institute of Hydraulic Engineering and Technical Hydromechanics at the Technische Universität Dresden, the Institute for Aquatic Ecology and Fish Biology Jena, the company SJE Ecohydraulic Engineering GmbH in Stuttgart and the Centre for Biorobotics at the Tallinn University of Technology in Estonia intend to outfit live fish with sensors to gather data to eventually replicate their behavior in the electronic fish. By 2022, the researchers intend to outfit the electronic replacement fish with pressure and acceleration sensors to capture data about how the fish pass through the turbines as an alternative to using live fish.

According to the Federal Institute of Risk Assessment, roughly 450,000 fish are used each year in live animal experiments at German hydroelectric water plants. Conducted on fish caught in the wild, the process is an extremely stressful one for fish and results in a mortality rate around 10%. Such tests, mandated by a European directive, are a measure of a plant’s “fish friendliness.”

“Following the European Water Framework Directive, German authorities require all run-of-the-river hydroelectric power plant operators to demonstrate with expert reports that the plants are passable for fish and other river wildlife," explained Stefan Hoerner from the Institute of Fluid Dynamics and Thermodynamics at the University of Magdeburg.

"It is true that the legislator prescribes the installation of fish protection systems in hydroelectric power plants, but not all of them are fully effective," Hoerner continued. "As a result, many animals end up swimming downstream through the turbines. Furthermore, predatory fish and birds like to stand by the installations and wait for prey that is easy to hunt."

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