Event Title
Concurrent Sessions B: Fish Passage in South America - Fish Concentration Downstream from the Dam in Brazil: Problems and Measures Taken to Solve Them
Location
Agriculture Production Theater, Oregon State University
Start Date
26-6-2013 3:50 PM
End Date
26-6-2013 4:10 PM
Description
Although they are important to economic growth, the river impoundments to electric energy production represent one of the main impacts for fishes. For the migratory species, the dams represent an obstacle, both to upstream and to downstream movement. The physical barrier constitutes the most obvious impact by the impoundment, causing frequently fish aggregation immediately below the dam, fact that increases the worry by electric energy segment. When turbines have to be stopped to maintenance, the fish in the tailrace can enter into the draft tubes, and mainly during turbine startup or dewatering, they can be injured or even be killed. Once turbine maneuvers to do maintenance are often required, preventive measures must be taken to avoid fish kills, for example, fish rescue and monitoring of water dissolved oxygen inside the draft tube during dewatering. The more fish inside the draft tube the greater the risk. Therefore, before risky maneuvers some technique shave been taken to minimized the impact on fishes, such as constant monitoring immediately below the dam, studies to increase knowledge about the fishes community in the tailrace, and the use of fish screens during startups to reduce turbine injuries. Results from a study about temporal variation in fish community in the tailrace at Três Marias Hydroelectric Dam, São Francisco River, suggest that risky maneuvers done during months of low precipitation could be a measure to minimize the impact of the operation on the downstream fish community. Moreover, it should be noted another developing study in the same area about fish behavior, using acoustic telemetry. The understanding of fish movement under different operational conditions can be helpful and provide subsidies to design strategies to minimize fish kills.
Concurrent Sessions B: Fish Passage in South America - Fish Concentration Downstream from the Dam in Brazil: Problems and Measures Taken to Solve Them
Agriculture Production Theater, Oregon State University
Although they are important to economic growth, the river impoundments to electric energy production represent one of the main impacts for fishes. For the migratory species, the dams represent an obstacle, both to upstream and to downstream movement. The physical barrier constitutes the most obvious impact by the impoundment, causing frequently fish aggregation immediately below the dam, fact that increases the worry by electric energy segment. When turbines have to be stopped to maintenance, the fish in the tailrace can enter into the draft tubes, and mainly during turbine startup or dewatering, they can be injured or even be killed. Once turbine maneuvers to do maintenance are often required, preventive measures must be taken to avoid fish kills, for example, fish rescue and monitoring of water dissolved oxygen inside the draft tube during dewatering. The more fish inside the draft tube the greater the risk. Therefore, before risky maneuvers some technique shave been taken to minimized the impact on fishes, such as constant monitoring immediately below the dam, studies to increase knowledge about the fishes community in the tailrace, and the use of fish screens during startups to reduce turbine injuries. Results from a study about temporal variation in fish community in the tailrace at Três Marias Hydroelectric Dam, São Francisco River, suggest that risky maneuvers done during months of low precipitation could be a measure to minimize the impact of the operation on the downstream fish community. Moreover, it should be noted another developing study in the same area about fish behavior, using acoustic telemetry. The understanding of fish movement under different operational conditions can be helpful and provide subsidies to design strategies to minimize fish kills.
Comments
Fabio Suzuki Biologist. Reseach with focus mainly in migratory fish, fish behavior and ichthyoplankton Ecology Currently PhD Student in Applied Ecology at Federal University of Lavras (Brazil) and doing my research with Fish Behavior using acoustic telemetry, and exchange visitor at Department of fisheries and wildlife, Oregon State University.