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#5942 Flooded Forest Stream, Rio Uaupés, Amazonas, Brazil

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Brazil, Amazonas, Sao Gabriel

Vaupés River (Uaupés River) is a tributary of the Rio Negro in South America. It rises in the Guaviare Department of Colombia, flowing east through Guaviare and Vaupés Departments. It forms part of the international border between the Vaupés department of Colombia and the Amazonas state of Brazil.

On the border it merges with the Papurí River and becomes known as the Uaupés. In 1847 an explorer saw a rapid, which hurled its waves 12 or 15 metres (40 or 50 ft) in the air, “as if great subaqueous explosions were taking place.”

The river continues on east through the Alto Rio Negro Indigenous Territory until it flows into the Rio Negro at São Joaquim, Amazonas. Vaupés is a blackwater river.

Submitted by
Arif Hikmet Başeğmez
GPS
0.1244796, -69.0706253
Geographical region
South America
Drainage Basin
Lower Rio Negro
River catchment
Rio Uaupés
Water body type
Igarapè
Water body name
Pirá
Water body part
Flood plain
Water body course
Middle course
Water body: tributary of
Rio
Tributary name
Uaupés

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Black water
Water transparency
Medium
Concentration of sediments
Low
Water temperature
28 °C
Water flow/curent
Slow

Chemical parameters

pH
4.5
Conductivity
30
GH
1 mg/l
KH
Dissolved Oxygen

Substrate in nature

Sand
White
Pebble/Gravel
None
Stone
None
Stone form
Silt/Mud
Beige
Leaves
Many
Driftwood
Many
Submerged terrestrial vegetation
Yes

Aquatic Biotope

Date of collecting
Collecting area
Water depth
Air temperature
Sunlight

Environment

Environment
Affected by human activity
Affected by human activity
Agriculture
Agriculture
Advanced
Surrounding area

Vaupés River (Uaupés River) is a tributary of the Rio Negro in South America. It rises in the Guaviare Department of Colombia, flowing east through Guaviare and Vaupés Departments. It forms part of the international border between the Vaupés department of Colombia and the Amazonas state of Brazil.

On the border it merges with the Papurí River and becomes known as the Uaupés. In 1847 an explorer saw a rapid, which hurled its waves 12 or 15 metres (40 or 50 ft) in the air, “as if great subaqueous explosions were taking place.”

The river continues on east through the Alto Rio Negro Indigenous Territory until it flows into the Rio Negro at São Joaquim, Amazonas. Vaupés is a blackwater river.

Underwater landscape

The waters are saturated with abundant tannins. There is a lot of organic matter accumulating on the ground. The sand is white in color and fine in size. Submerged tree trunks, driftwood and terrestrial plants are visible.

Fishes:

  • Paracheirodon axelrodi (Characidae)
  • Apistogramma elizabethae (Cichlidae)
  • Ivanacara adoketa (Cichlidae)
  • Pterophyllum altum (Cichlidae)
  • Nannostomus sp. (Lebiasinidae)
  • Apistogramma uaupesi (Cichlidae)

Aquatic plants:

  • Helanthium tenellum (Alismataceae)
  • Pontederia crassipes (Pontederiaceae)
  • Myriophyllum aquaticum (syn. Myriophyllum brasiliense) (Haloragaceae)
  • Echinodorus grisebachii (syn. Echinodorus amazonicus) (Alismataceae)
  • Eleocharis acicularis (Cyperaceae)
Threats to ecology

The Uaupes, a tributary of the Rio Negro, is a blackwater river. The ecology of blackwater rivers differs from temperate aquatic systems. In temperate climates, the base of the food chain is usually microflora, produced by photosynthetic and chemosynthetic action on nutrients in the water. Early researchers were faced with the apparent paradox that many Amazonian rivers, while containing both low levels of nutrients and low in situ production of primary phytoplankton, nonetheless support flourishing fish populations.

Food supplies in blackwater rivers come from external sources. River margins provide food for fish – vegetable matter such as leaves, fruits, flowers, seeds, and microflora, and numerous animal forms such as insects, insect larvae, arachnids, crustaceans, and worms. This food enters the river as floating and decomposed matter and mud.

Water levels fluctuate with seasonal rain. When flooding peaks , waters overspill their banks merging aquatic and terrestrial zones, and allowing fish into the flooded forests to feed. Some of the fish populations of these rivers have evolved to exploit increased numbers of foods available during floods and to store these energy reserves as fatty deposits.

Uaupes soils, podsols and latosols, are eroded from the ancient Guyana Shield through which the Uaupes River flows. These soil types are typical of blackwater areas.

Podsols result from intense weathering of soils in a strongly acid medium. Leaching removes soluble minerals leaving the soil high in aluminum and iron compounds. The unweathered surface material is a white sand, devoid of important nutrients such as nitrogen and phosphorous.

Latosols are weathered soils rich in iron. When exposed to repeated drying and moistening, the iron segregates, forming nodules and concretions which cement to a rock-like hardness known as laterite.

These soils’ principal source of nutrients is derived from the accumulation of leaf fall and other debris from the forest. Upon clearing, nutrients are quickly eroded. Thus, to remove the forest cover is to remove the nutrients of both the terrestrial and aquatic systems. Without the leaf litter from the forest, the soils become either white sands or brick-like laterites, both inhospitable to agriculture. Finally, were the forest margin to be denuded for agriculture, these soils would quickly erode, altering the river channel and depositing silt in the river.

Agriculture is a short-lived phenomenon in deforested blackwater regions because nutrient supply is quickly exhausted. Greater protein yields per hectare from blackwater areas are obtained by maintaining the forest as a grazing ground for fish.

One can clearly see how the soil layer of fertile soil in the Amazon is unstable and how little it needs to be degraded. Tribes living in this area cultivate to a very limited extent, therefore their impact on the environment is small. Much worse results are caused by a lumbering timber economy, which by cutting trees in huge areas causes soil sterilization by removing a thin layer of humus. In the place of the cut forest, nature is reborn very slowly.

A separate threat to this region is the legal and illegal exploration of raw materials. When extracting, for example, gold, mercury or cyanide is used. The waste after the recovery of gold goes very often directly to smaller and larger rivers, causing mass poisoning of fish and other aquatic animals.

This creates a huge threat to the people living in this area. It is very common to use violence against the Indians, and even murders of some tribesmen to intimidate others.

Riparian zone

Trees near the aquatic habitat
Many -