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Brazil's Balbina Dam created an "artificial archipelago of 3,546 islands." (Photo: Eduardo M. Venticinque)

Brazil's Balbina Dam created an "artificial archipelago of 3,546 islands." (Photo: Eduardo M. Venticinque)

Research Confirms Hydroelectric Dams Not Environmentally Friendly After All

Study exposes dramatic biodiversity loss as a result of Brazil's Balbina Dam

Sarah Lazare

A new study by University of East Anglia researchers confirms what numerous Indigenous communities have long charged: gigantic hydroelectric dam construction projects are not environmentally friendly, as proponents claim, but in fact pose a profound threat to biodiversity and life in the Amazon.

Widespread Forest Vertebrate Extinctions Induced by a Mega Hydroelectric Dam in Lowland Amazonia was published Wednesday in the journal PLOS ONE. The paper examines the environmental impact of Brazil's Balbina Dam—which is located near the city of Manaus in the Amazonas state and is one of the largest hydroelectric dams in the world.

The construction of the dam in the 1980s transformed what used to be a lush rainforest forest landscape into an "artificial archipelago of 3,546 islands," explains a summary of the research.

Not surprisingly, when hundreds of square miles of jungle were flooded with water, the wildlife who called that forest home—including mammals, birds, and tortoises—suffered dramatic population loss, with large vertebrates completely disappearing from almost all of the artificial islands, the report concludes.

Furthermore, the summary explains, "Of the 3,546 islands created, only 25 are now likely to harbour at least four fifths of all 35 target species surveyed in the study."

"Hydroelectric dams have been thought to be an environmentally friendly source of renewable power—and in recent years they have been built to supply the burgeoning energy demands of emergent tropical countries," lead author Dr. Maíra Benchimol said in a press statement. "Our research adds evidence that forest biodiversity also pays a heavy price when large dams are built."

UAE Professor Carlos Peres added: "The Brazilian government is currently planning to build hundreds of new dams in some of the world’s most biodiverse tropical forest regions. But the high biodiversity costs of mega dams should be carefully weighed against any benefits of hydropower production."

Nearly 70 percent of power in Brazil is generated by hydroelectric dams.


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