Protecting the downstream migration of salmon smolts from hydroelectric power plants with inclined racks and optimized bypass water discharge.

The sustained development of hydropower energy in the last century has caused important ecological impacts, promoting recent advances in efficient mitigation measures to be implemented in existing and future hydropower plants. Although upstream fish migration has been largely addressed with the development of fish-pass infrastructures, downstream passage solutions are often missing or inefficient, strengthening the need for their improvement and efficiency assessment. The efficiency of horizontally inclined (26°) low bar spacing racks associated to a bypass was assessed using salmon smolts radiotelemetry along three successive hydropower plants (HPP) in the Ariège River (southern France).

[Body size, ecological tolerance and potential for water quality bioindication in the genus Anacroneuria (Plecoptera: Perlidae) from South America].

Knowledge about the biology and ecology of neotropical aquatic taxa is crucial to establish general ecological rules and water protection systems. Based mainly on published data, the present work shows the following biological and ecological characteristics of Anacroneuria species (Klapálek 1909): (a) the wide range of environmental conditions of rivers where Anacroneuria species occur, (b) species number decreases along an increasing elevation gradient, (c) body size increases in relation to the maximum altitude of occurrence, (d) altitudinal range increases with body size, (e) there is a constant relationship between male and female body size, and finally, (f) larger females lay larger eggs. In temperate countries, the family Perlidae in general, and the genus Anacroneuria in particular, are viewed as excellent water quality indicators.

Local-scale species-energy relationships in fish assemblages of some forested streams of the Bolivian Amazon.

Productivity (trophic energy) is one of the most important factors promoting variation in species richness. A variety of species-energy relationships have been reported, including monotonically positive, monotonically negative, or unimodal (i.e.