Size:
840,000 sq. km (336,000 sq. miles)
Habitat type:
Large Rivers
Geographic Location:
North-central South America: Brazil, Columbia, and Peru
Conservation Status:
Relatively Stable/Intact
About the Area
The Amazon is the second longest river in the world (after the Nile), stretching 6,400 kilometers and containing 20 percent of the Earth's fresh water. This Global ecoregion is made up of these terrestrial ecoregions: Iquitos varzea; Gurupa varzea; Rio Negro campinarana; Marajó varzea; Purus varzea; Monte Alegre varzea.
The varzea and igapó freshwater ecosystems of the Amazon Basin represent some of the world's most extensive seasonally inundated floodplain forests. Every year, fish, reptiles, and other aquatic animals migrate into these newly available habitats to feed and reproduce, then return to the main channels when the floodwaters recede.Essential for the reproduction of many floodplain trees is the dispersal of their seeds by fruit-eating animals, including several fish species. This cycle of flooding, and the annual regeneration that it produces, represent a globally outstanding ecological phenomenon.
Local Species
The entire Amazon basin contains the largest number of freshwater fish species in the world, with an estimated number of over 3000 species. A few of the characteristic fishes of this ecoregion are the fruit-eating Tambaqui (Colossoma macropomum), Arawana (Osteoglossum bicirrhosum), Pirarucu (Arapaima gigas), Arapaima (Arapaima gigas), Dourada catfish (Brachyplatystoma flavicans), and one of the world's few surviving lungfishes - Lepidosiren paradoxa and Tucunaré (Cichla acellaris).
Mammals include Pink river dolphin or boto (Inia geoffrensis), Grey river dolphin or tucuxi (Sotalia fluviatis), Manatee (Trichecus inunguis), and the rare Uakari (Cacajao calvus). The largest river turtle in South America, Podocnemis expansa, is also found here, as is the highly endangered Black caiman (Melanosuchus niger).
Threats
In the flooded forests, selective logging of the kapok tree and virola is accelerating deforestation and wiping out populations of the above species over large regions. Open floodplains are being converted for cattle ranching, which can include introduced water buffalo (Bubalus bubalis).
Other threats include: overfishing - particularly of the largest species; mercury pollution from gold mining in smaller streams; increasing population centers and the resultant untreated sewage; construction of roads and dams that have the potential to block species movements and alter hydrology.