Impactos ecológicos y socioeconómicos de la construcción de represas sobre la ictiofauna y las pesquerías de los grandes ríos de América del Sur

BAIGUN CLAUDIO

Agua+Humedales

UNSAM

Lugar: San Martin; Año: 2020; p. 256 - 277

South America, has a huge potential for the development of hydroelectricprojects, which are responsible for the fragmentation ofover 3,000 km of rivers. In the area of the upper Paraná Basin alone,there are more than 130 dams with a height of 10 m or more, while theamount of projects in the Amazon Basin is expected to increase overthe 21st century. Dams can bidirectionally affect hydrology, geomorphologyand biotic resources. Downstream, they can promote changesin the flow regime, which sometimes alters water quality; upstream,the formation of large reservoirs modifies the environmentalconditions of rivers and water quality, and in tropical areas it leads toincreasing methane emissions, thus contributing to global warming.Additionally, reservoirs contribute to the alteration of fish communities?composition and, as a result of a reduction in the presence ofmigratory species, have an impact on the quality of fisheries after thetrophic stabilization stage is completed. In spite of the constructionof fish passages, mitigations efforts have not been successful so far,in the light of the results obtained in the Yaciretá and Salto Grandedams as well as others located in Brazil. The development of damprojects in South America over the 21st century should be assessedthrough a case-specific cost-benefit analysis based on their energetic,environmental, social and economic impact. It is necessary toadopt bioengineering criteria and an ecosystemic approach in orderto mitigate the effects on the resources provided by large rivers andtheir main associated factors.