RIVER IN PERIL – AN UPDATE ON RIO XINGÚ

Two years ago, I reported on the incredible diversity of endemic fish that have adapted to the rapids of the Xingú River, located in Brazil’s Para state. The local fish population includes many bizarrely-shaped specimens (i.e. plecos, cichlids, characins, etc.), many of whom exemplify special colors and characteristics after having adapted to life in this fast-moving water.

This adaptation is necessary for the fish to feed and survive in the Xingú rapids. However, if you change the characteristics of the river, it will inevitably have devastating results on the life that inhabits it. Unfortunately, this is exactly what is happening as we publish this update.

Belo Monte Dam Project

The Belo Monte Dam project is the second largest in the world, and it will forever alter the flow of the Xingú’s most diverse sector: The Volta Grande (Big Curve).

Regrettably, this is where the majority of Xingú fish are most abundant. The Dam will block the flow of the Xingú just downstream from Altamira, causing a gigantic reservoir to form that will destroy fish habitats within the rocky rapids and flood islands up to 100 km (62 miles) upstream, to the mouth of the Iriri River.

The flow of the Xingú will be diverted via a gigantic barrier into Belo Monte, where water will pass through a massive turbine house and then directly into the Amazon lowland. Behind the barrier, the Volta Grande will be left with water levels lower than those found during peak dry season.

The Fate Of The Local Species

How will fish survive in the immense standing water reservoir upstream from Altamira? Those that have evolved to pick at sponges, insect larvae and algae on the barren rocks of the rapids will experience an absence of their regular food source. Meanwhile, species located below the intake dam will have to contend with a stable waterway, devoid of the seasonal fluctuations that once gave them access to food sources and rich vegetation.

Seasonal Killi fish (i.e. Petunia xinguensis and Plesiolebias Altamira) that evolved to live only 4 months of the year within puddles that formed from flood waters on larger islands such as Ilha Arapujá, will surely be wiped out as their habitats become submerged deep inside the reservoir.

The list of fish threatened directly by the changes to the Volta Grande and reservoir around Altamira is almost endless; zebra pleco (Hypancistrus zebra) or ‘L46’, Hypancistrus spec. or ‘L174’, Hypancistrus spec. or ‘L66’, the medusa pleco (Ancistrus ranunculus) or ‘L34’, the goldy pleco (Scobinancistrus aureatus) or ‘L14’, and so many others.

Although the overall impact of the dam won’t be felt for a few years, life in and around the Amazon’s most unique river will be irreversibly changed forever. Aquatic species will of course perish, but so will certain terrestrial mammals. We also add to this the 20,000 indigenous people that will be displaced from ancestral grounds due to the flooding from the altered waterways, all in the name of “progress.”

Social Responsibility

As aquarium hobbyists, we have the privilege of nurturing a small slice of nature in our homes, but as conscientious human beings, we have a greater duty to educate ourselves about issues that not only affect these faraway natural resources, but also those in our own backyards. We’re all connected in one way or another on this planet, so let’s ensure we take good care of it.

We’ll soon need to turn our attention to the Rio Tapajos project, with construction scheduled to begin in a few years. For more information or to donate and help protect the Xingú River, visit these Websites:

http://www.internationalrivers.org/campaigns/belo-monte-dam

http://www.survivalinternational.org/about/belo-monte-dam