The source of the Rio Negro lies inColombia, in theDepartment of Guainía where the river is known as theGuainía River.[9] The young river generally flows in an east-northeasterly direction through thePuinawai National Reserve, passing several small indigenous settlements on its way, such as Cuarinuma, Brujas, Santa Rosa and Tabaquén. After roughly 400 km (250 mi) the river starts forming the border between Colombia'sDepartment of Guainía and Venezuela'sAmazonas 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 (75 mi) further downstream the river receives theCasiquiare canal from the left (north), forming a unique link between theOrinoco and the Amazon river basin.
The river now continues in a southeastern direction passing the Venezuelan town ofSan Carlos de Río Negro, its largest settlement on the river, and Colombia'sSan 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 (160 mi) the Rio Negro reaches thePiedra del Cocuy, an igneous rock formation from the Precambrian era, belonging to theGuyana Shield. Here theTripoint of Colombia, Venezuela and Brazil is found in the middle of the river and it now completely entersAmazonas State, Brazil. After passingCucuí, the river continues south, only temporarily turning west for several kilometers. InMissão Boa Vista theIçana River joins the Rio Negro and in São Joaquim theUaupes 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 passesSao 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.
After theMarié River enters the Rio Negro the river continues its eastward course forming many large islands and becoming very wide at several locations. It passes local communities such asSanta Isabel do Rio Negro. During thewet season, the river floods the country far and wide here, sometimes to a width of 30 km (19 mi), for long distances. During this season, from April until October, it is a succession of lagoons, full of long islands and intricate channels with a lot of water wildlife. Near Carvoeiro the last major tributary of the Rio Negro, theBranco River joins the Rio Negro and the river temporarily forms the border between the state ofRoraima andAmazonas State, Brazil. The river now takes a more southeastern course, becoming again very wide in many stretches before reaching the biggest city on its courseManaus.
TheAnavilhanas National Park, a 350,018 ha (864,910 acres) conservation unit that was originally an ecological station created in 1981, protects part of the Anavilhanas river archipelago in this part of the river.[10]Below the archipelago, it meets theSolimões River to form theAmazon River, creating a phenomenon known as theMeeting of Waters.
The river was named by the Spanish explorerFrancisco 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, andNative American populations were greatly diminished after contact with Eurasian diseases.[9] In 1800 German scientistAlexander von Humboldt[17] and French botanistAimé Bonpland explored the river.[18] During 1852–1854Richard Spruce andAlfred Russel Wallace made numerous observations and botanical collections.[19] During a 1924–25 expedition,Alexander H. Rice Jr. ofHarvard 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 andshortwave radio for mapping of the region. In 1968 the Rio Negro was navigated by anSRN6 hovercraft during aNational Geographic expedition.[20] This area was the filming location for Survivor:The Amazon in 2003.[citation needed]
While the nameRio Negro meansBlack River, its waters are similar in colour to strongtea, which is typical ofblackwater rivers. The dark color comes fromhumic acid due to an incomplete breakdown of phenol-containing vegetation from sandy clearings.[citation needed] 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 manyIndigenous 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 highspecies 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 100endemics and severalundescribed species.[21] Among these are many that are important in theaquarium trade, including thecardinal tetra.[21] As a result of theCasiquiare canal, many aquatic species are found both in the Rio Negro and Orinoco. Because the Casiquiare includes both blackwater andclear- towhitewater sections, only relatively adaptable species are able to pass through it between the two river systems.[22]
Henryk Wars and his Orchestra composed and recorded apasodoble named "Rio Negro", with Edward Jasinski in 1938, which became an evergreen hit in Poland.[23]
^Daum, Andreas W. (2024).Alexander von Humboldt: A Concise Biography. Trans. Robert Savage. Princeton, N.J.: Princeton University Press. p. 69.ISBN978-0-691-24736-6.
^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.
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.ISBN90-5103-016-9
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.ISBN85-7591-042-6.
