The Piracema Canal is a 10.3 km long fishway with a total elevation gain of 120m. It is located at the Itaipu Dam, on the Parana River between Brazil and Paraguay. The Canal comprises a natural stream, the Bela Vista River (6.8 km long) and an artificial subsystem (technical reaches and lakes; last 3.5 km). Most of the migratory species caught below the Itaipu Dam were captured in the Bela Vista River, some in high abundance. Studies conducted with different fishing gears indicate that few individuals reach the upper end of the system, with rates estimated at 0.5% (using gillnets), 1.6% (radiotelemetry) and 18.4% (PIT -tag telemetry). This range of results may be attributed to methodological variations, or to different periods in which these studies were conducted. The segment called Drainage Channel (200m long, 6% slope and turbulent) represents the transition from the natural to the artificial subsystem; this section appears to act as a barrier to fish passage, conferring selectivity to the system. Tagged fish below the Drainage Channel took on average 10 days longer to reach the end of the system than the tagged fish just above this segment. The long time span taken by migratory fish to ascend suggests that they may be using the system mainly for dispersal, but all individuals have potential to spawn in the next reproductive season, because earlier studies clearly demonstrate that they can find the spawning places located upstream Itaipu Reservoir. Therefore, the Piracema Canal contributes to the biodiversity conservation of potamodromous fish in the last lotic stretch of the Parana River inside the Brazilian territory
