Researchers at the University of East Anglia (UEA) in the UK have indicated that construction of hydroelectric dams have been affecting tropical forest biodiversity, contrary to belief that they are environmentally friendly.
The study titled as ‘Widespread forest vertebrate extinctions induced by a mega hydroelectric dam in lowland Amazonia’ has been published in the July edition of the journal PLOS ONE.
According to the findings, development of the Amazonian Balbina Dam had resulted in massive loss of mammals, birds and tortoises in the region.
UEA former PhD student and lead author for the study Dr Maíra Benchimol said: "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.
"According to the findings, development of the Amazonian Balbina Dam had resulted in massive loss of mammals, birds and tortoises in the region."
"Previous studies have shown that large dams result in severe losses in fishery revenues, increases in greenhouse gas emissions, and socioeconomic costs to local communities.
"Our research adds evidence that forest biodiversity also pays a heavy price when large dams are built."
The UEA research team had carried out surveys for around two years on 40 forest sites, which included 37 islands isolated by the hydroelectric reservoir built on the Balbina Lake and three neighbouring continuous forest areas.
Surveys were also carried out on land and tree dwelling vertebrates at these sites.
UEA School of Environmental Sciences professor Carlos Peres said: "… We’re only beginning to realise the staggering extent of extinctions in forest areas that remain above water as habitat islands.
"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."
Image: Balbina Dam in Amazon, Brazil. Photo: courtesy of Seabirds / Wikipedia.