· Between Big Rivers
· Special Features
· Did You Know?
· Wild Side
· Cause for Concern
· Looking Ahead

Global 200 Snapshot

Though poorly investigated, the rivers and streams of the Guianan Freshwater ecoregion are known to support a highly diverse and intact group of endemic animals.  

Between Big Rivers

Put the words "South America" and "river" together, and most people think of the mighty Amazon, or perhaps the long Orinoco. But along the northeast coast of South America, the rivers of this ecoregion drain an area called the Guyana Shield and contain a wide range of flowing water habitats, including cataracts, rapids, and flooded forests.

Special Features

At the center of the Guianan Freshwater ecoregion is a series of mountain ranges, including the Acaraí, Pacaraima, and Tumucumaque. From these peaks flow many rivers. Some rush over rocky rapids and steep falls, while others wander gently through plains or flood dense forests. The tallest waterfall in the world is in this ecoregion, the 3,200 feet (980 m) Angel Falls, as well as some of the Earth's oldest land formations. In many rivers, waterfalls have created isolated bodies of water, where many endemic species have evolved.

	So much water from the Guianan Freshwater ecoregion flows into the Atlantic that it changes the temperature of the ocean. The presence of all this freshwater creates the Guiana Current, a flow of surface water that’s much warmer than the surrounding ocean water usually is.

Wild Side

Among the many species found in this important freshwater system are two fish, the imperiled arapaima and arowana, as well as the giant South American river turtle, and black caiman.

Cause for Concern

Compared to many other ecoregions, the Guianan Freshwater is in good condition and many species have stable populations. However, valuable game species, such as the enormous arapaima and some reptiles, are imperiled as a result of overexploitation and an illegal border trade. Also, trees are often cut down for timber and to clear land for agriculture. This causes soil to erode and flow into the rivers, causing a decline in water quality. Agricultural activities contribute pesticides to the ecoregion’s waters, and industrial and domestic wastes have polluted much of the water on the coastal plain. Gold and bauxite mining are important activities in this ecoregion, and a series of cyanide spills linked to gold mining activities warns of a continuing threat in this ecoregion. Finally, water extraction may become a problem, even in this well-watered area.

Looking Ahead

Check back soon for more about the conservation of this ecoregion.