Scientists are concerned over the impact on the fragile ecosystem
A new study published in the academic journal Science Advances raised concerns regarding the ecological impact dam building is having in the Amazon River Basin, South America. Already, the hydropower dams are spurring changes in the fragile Amazon ecosystem, displacing indigenous peoples and disrupting sediment flows. 142 hydropower dams are in operation or under construction and 160 are under consideration, according to a satellite study conducted by the research team.
A once populous fish in the region called a dorado is dwindling rapidly. Prior to dam construction for flood control and electricity, the fish breed would swim from the mouth of the Amazon River to the Mamore River to spawn, but it can no longer make it up river with the dams blocking the way. Instead, a different kind of fish called a manitoa is strong enough to swim upstream and disrupt the ecosystem.
Sandra Bibiana Correa, a freshwater ecologist at Mississippi State University, is concerned that the effects could trickled down to plant life as many fish will eat fruits in the Amazon Basin and spread the seeds elsewhere. Additionally, the dams trap sediment flows and nutrients that farmers and plants in the basin need for growth.