Rio Negro (Amazon)

Geography

Upper course

The source of the Rio Negro lies in Colombia, in the Department of Guainía where the river is known as the Guainía River. The young river generally flows in an east-northeasterly direction through the Puinawai National Reserve, passing several small indigenous settlements on its way, such as Cuarinuma, Brujas, Santa Rosa and Tabaquén. After roughly 400 km the river starts forming the border between Colombia's Department of Guainía and Venezuela's Amazonas State. After passing the Colombian community of Tonina and Macanal the river turns southwest. Maroa is the first Venezuelan town the river passes. 120 km further downstream the river receives the Casiquiare canal from the left (north), forming a unique link between the Orinoco and the Amazon river basin.

Middle course

The river now continues in a southeastern direction passing the Venezuelan town of San Carlos de Río Negro, its largest settlement on the river, and Colombia's San Felipe. In this stretch the river is constantly fed with tributaries from both sides, and it quickly grows in size creating large river islands, a common feature for all rivers in the Amazon basin. After forming the border between Colombia and Venezuela for 260 km the Rio Negro reaches the Piedra del Cocuy, an igneous rock formation from the Precambrian era, belonging to the Guyana Shield. Here the Tripoint of Colombia, Venezuela and Brazil is found in the middle of the river and it now completely enters Amazonas State, Brazil. After passing Cucuí, the river continues south, only temporarily turning west for several kilometers. In Missão Boa Vista the Içana River joins the Rio Negro and in São Joaquim the Uaupes River, the largest tributary of the Rio Negro, also enters from the right hand side. The Rio Negro now turns markedly towards the east, forming several rapids and small islets on its way. It then passes Sao Gabriel da Cachoeira an important commercial city. After several more rapids and imposing views of the Adormecida mountain chain the river leaves the Guyana shield it traversed in its upper and middle course.

Lower course

The Anavilhanas National Park, a 350018 ha conservation unit that was originally an ecological station created in 1981, protects part of the Anavilhanas river archipelago in this part of the river.{{citation|ref=|language=pt Below the archipelago, it meets the Solimões River to form the Amazon River, creating a phenomenon known as the Meeting of Waters.

Major tributaries

List of the major tributaries of the Rio Negro (from the mouth upwards)

Discharge

Average discharge

History

The river was named by the Spanish explorer Francisco de Orellana, who first came upon it in 1541. By the middle of the 17th century, Jesuits had settled along its banks in the midst of numerous tribes: Manau, Aruák, and Trumá Indians. After 1700 slaving along the river was common, and Native American populations were greatly diminished after contact with Eurasian diseases. In 1800 German scientist Alexander von Humboldt and French botanist Aimé Bonpland explored the river. During 1852–1854 Richard Spruce and Alfred Russel Wallace made numerous observations and botanical collections. During a 1924–25 expedition, Alexander H. Rice Jr. of Harvard University traveled up the Orinoco, traversed the Casiquiare canal, and descended the Rio Negro to the Amazon at Manaus. It was the first expedition to use aerial photography and shortwave radio for mapping of the region. In 1968 the Rio Negro was navigated by an SRN6 hovercraft during a National Geographic expedition. This area was the filming location for Survivor:The Amazon in 2003.

Fauna and flora

While the name Rio Negro means Black River, its waters are similar in colour to strong tea, which is typical of blackwater rivers. The dark color comes from humic acid due to an incomplete breakdown of phenol-containing vegetation from sandy clearings. The river was named because it looks black from a distance.

Much has been written on the productivity of the Rio Negro and other blackwater rivers. The older idea that these are "hunger rivers" is giving way, with new research, to the recognition that the Rio Negro, for example, supports a large fishing industry and has numerous turtle beaches. If explorers did not find many Indigenous peoples along the Rio Negro during the 17th century, it is likely that their populations were reduced because of new infectious diseases and warfare rather than low river productivity.

Rio Negro has a very high species richness. About 700 fish species have been documented in the river basin, and it is estimated that the total is 800–900 fish species, including almost 100 endemics and several undescribed species. Among these are many that are important in the aquarium trade, including the cardinal tetra.

In media

The sixth season of Survivor, Survivor: The Amazon was filmed in Rio Negro in 2003. Also Meeting of the Waters by Animal Collective was recorded in Rio Negro in 2016.

Henryk Wars and his Orchestra composed and recorded a pasodoble named "Rio Negro", with Edward Jasinski in 1938, which became an evergreen hit in Poland.

Notes

References

• Goulding, M., Carvalho, M. L., & Ferreira, E. J. G. (1988). Rio Negro, Rich Life in Poor Water : Amazonian Diversity and Foodchain Ecology as seen through Fish Communities. The Hague: SPB Academic Publishing.
• Saint-Paul, U., Berger, U., Zuanon, J., Villacorta Correa, M. A., García, M., Fabré, N. N., et al. (2000). "Fish communities in central Amazonian white- and blackwater floodplains," Environmental Biology of Fishes, 57(3), 235–250.
• Sioli, H. (1955). "Beiträge zur regionalen Limnologie des Amazonasgebietes. III. Über einige Gewässer des oberen Rio Negro-Gebietes." Arch. Hydrobiol., 50(1), 1-32.
• Wallace, A. R. (1853). A narrative of travels on the Amazon and Rio Negro, with an account of the native tribes, and observations on the climate, geology, and natural history of the Amazon Valley. London: Reeve.
• Wright, R. (2005). História indígena e do indigenismo no Alto Rio Negro. São Paulo, Brazil: UNICAMP & Instituto Socioambiental. .

References

1. (1979). "The Inland waters of Latin America". [[Food and Agriculture Organization.
2. (2022). "Suspended sediment transport estimation in Negro River (Amazon Basin) using MSI/Sentinel-2 data". Revista Brasileira de Geomorfologia.
3. "Amazon basin water resources observation service".
4. (2021). "The Negro River in the Anavilhanas Archipelago: Streamflow and geomorphology of a complex anabranching system in the Amazon". Earth Surface Processes and Landforms.
5. Jamie, Towner. (2019). "Assessing the performance of global hydrological models for capturing peak river flows in the Amazon basin".
6. (2010). "Rating curves and estimation of average water depth at the upper Negro River based on satellite altimeter data and modeled discharges". Journal of Hydrology.
7. Tannenbaum, Frank. (29 August 2012). "TEN KEYS LAT AMER". Knopf Doubleday Publishing Group.
8. (28 May 2014). "Waters". Amazon Waters.
9. (2001). "Rivers of the World: A Social, Geographical and Environmental Sourcebook". ABC Clio.
10. (Jan 2019). "PLANO ESTADUAL DE RECURSOS HÍDRICOS DO AMAZONAS, (PERH/AM) - RT 03 - DIAGNÓSTICO, PROGNÓSTICO E CENÁRIOS FUTUROS DO RECURSOS HÍDRICOS DO ESTADO - TOMO III".
11. "Amazon".
12. (2005). "Estimating cell-to-cell land surface drainage paths from digital channel networks, with an application to the Amazon basin". Journal of Hydrology.
13. "SGB-CPRM".
14. (2011). "Assessment of different precipitation datasets and their impacts on the water balance of the Negro River basin". Journal of Hydrology.
15. (1997). "HYDROLOGIE DU BASSIN AMAZONIEN".
16. {{cite EB1911. George Earl. Church. (1911b)
17. Daum, Andreas W.. (2024). "Alexander von Humboldt: A Concise Biography". Princeton University Press.
18. Huber, Otto and Wurdack, J. J. (1984), History of botanical exploration in Territorio Federal Amazonas, Venezuela (Smithsonian contributions to botany; City of Washington: Smithsonian Institution Press) iii, 83 p.
19. (2007-10-07). "Graham Clarke". [[The Daily Telegraph]].
20. Hales, J., and P. Petry (2013). ''[http://www.feow.org/ecoregions/details/rio_negro Rio Negro] {{Webarchive. link. (2017-12-01 ''. Freshwater Ecoregions of the World. Retrieved 12 February 2013)
21. (2015). "Description of a new Heros species (Teleostei, Cichlidae) from the Rio Orinoco drainage and notes on Heros severus Heckel, 1840". Bulletin of Fish Biology.
22. "Rio Negro : pasodoble - Stare Melodie".