Author(s): B. A. F. Duarte; H. A. Santos; M. A. Castro
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Keywords: No Keywords
Abstract: Nowadays some negative externalities due to antropics impacts are common in Brazilian rivers. Interruptions in river such as the barrier caused by dams promote negative impact on aquatic community. The migratory species are directly affected because in some phase of their life they need to move along the river. In order to solve this environmental problem, structures were developed to allow the passage of fishes through the dams. The fishways have been widely built in the entire world. In Brazil, after the environment laws implementation, these structures are been constructed based on European and American fishpasses. The aim of this study is to obtain the velocity and turbulence in fishladder and to compare theses results with the preference velocity of neotropical fishes. The design of this fishladder, which was built in laboratory, was the vertical slot, the most common type used in Minas Gerais state (Brazil). The slot arrangement was based on Katopodis and the velocity measured were made by turbine flowmeter. Significant variations in average speeds occurred along the different depths in the first pools. Recent studies have showed the selectivity for different neotropical fishes in some fishladder built in Brazil. Concerning on the big Brazilian biodiversity, it has been considered the main challenge of fishpassages design. The result of this study can explain the selectivity, which depends on fishladder enter and attraction system.
Year: 2009