Telemetry Studies in the Paraopeba River, São Francisco Basin, Brazil

The Paraopeba river is a tributary of the São Francisco river, in southeastern Brazil (drainage area: 12.090 km²; extension 510 km). There are three dams along its course, two of them with fish passages. The river had a free stretch of 386 km until 2010, when the third dam was built in its lower portion. A previous mark-recapture program (1997-2000) showed wide usage of the river by migratory species, including fish passage through a ladder installed in 1994 at the middle dam. We began measuring fish migratory behavior using radiotelemetry in 2005. From 2005 to 2012, 209 fishes of 3 species were tagged: 87 Prochilodus costatus, 97 Salminus franciscanus, and 25 Prochilodus argenteus. Fish were tagged in the upper and lower portions of Paraopeba river, and have been tracked by boat, airplane, and with fixed telemetry stations. Results confirmed that specimens of each species use most of the free stretches of river. Individually, the higher linear home ranges reached 154.29 km for P. costatus, 242.52 km for S. franciscanus, and 198.91 for P. argenteus. Fish moved both upstream (for reproduction) and downstream from where they were tagged. These are important findings for migratory species conservation, threatened by new dam constructions.