The Amazon: Large-scale degradation of freshwater ecosystems | WWF

The Amazon: Large-scale degradation of freshwater ecosystems

Posted on
22 March 2016
The freshwater ecosystems in the Amazon are under threat by deforestation and especially by connectivity interruption. More than 250 new hydropower dams are planned for the region. If all go forward as planned, only three free-flowing tributaries of the Amazon River will remain, compromising the river network and the provision of ecosystem services to the societies and economies in the region, to the countries of South America and to the world.
On this World Water Day, WWF Living Amazon calls attention to impacts on hydrological connectivity. A scientific article written by Leandro Castello and Marcia Macedo and published by Global Change Biology magazine, analyzes drivers of degradation, evaluates their impacts on hydrological connectivity, and identifies policy deficiencies that hinder freshwater ecosystem protection in the Amazon. The article is available at
Usually known for its forests and the immense volume of deforestation each year, the Amazon is also the largest river system in the world with more than 100.000 km of rivers and streams.
The report State of the Amazon: Freshwater Connectivity and Ecosystem Health, launched by  WWF Living Amazon Initiative in 2015 and the basis for the scientific article,  provides a comprehensive assessment of the current state of Amazon freshwater ecosystems and highlights  textboxes presenting worst case scenarios and potential positive paths with integrated approaches for watershed planning and management for maintaining Amazon ecological stability. The full report can be downloaded at:
Amazon Facts and Figures:
Biodiversity:  The Amazon region is number 1 in biodiversity on Earth, with one new species presented to science every 3 days in the last 14 years - not counting insects and microorganisms.  And there is much yet is to be discovered.
Freshwater biodiversity:  Freshwater connectivity is particularly critical for fisheries and regional food security, since many economically and ecologically important fish species depend on lateral or longitudinal migrations for parts of their life cycles. Long-distance migratory catfish, for example, travel thousands of kilometres from the Amazon’s estuary to the headwaters of white-water rivers, where they spawn in the Andean foothills.
Amazon Watershed: The Amazon watershed spans 6.9 million km2, connecting nine countries in South America - Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, Suriname and French Guiana/ France. The hydrological connections help maintain over 1 million km2 of freshwater ecosystems, which sustain a wealth of biological diversity and productive fisheries that are a vital source of protein and income for Amazonians.  The Amazon River network is the lifeblood of the regional economy.
The Amazon River: The Amazon River itself is the largest in the world in water volume and flows through 6,992 Km. At its mouth, the Amazon discharges about 6,700km3 yr-1 of freshwater into the Atlantic Ocean, about 20 per cent of global surface river flows.
Deforestation: almost 20 per cent of the Amazon Biome – 6,5 million km2, has already been deforested.
The Amazon River Dolphin, Inia geoffrensis, Tapajos River, Santarem region, Pará State, Brazilian Amazon.
© Adriano Gambarini / WWF Living Amazon Initiative
El estado de la Amazonia: Conectividad de agua dulce y salud de los ecosistema
© WWF Living Amazon Initiative
Upstream from the Salto Augusto, upper Juruena River, Mato Grosso, Brazil.
© Zig Koch / WWF Living Amazon Initiative