Rio Poranga, São Gabriel da Cachoeira

Sponsored by

Brazil, Amazonas, São Gabriel da Cachoeira

The Rio Poranga, also known as Igarape Poranga, is a tributary of the upper Rio Negro in the Amazonas state in the Sao Gabriel da Cochaeira region of Brazil, near the city of Cucui. Rio Poranga is the source of the Corydoras duplicareus. The outline of the river is clearly visible, although it is not described on the maps. Thanks to the help of local anglers and famous aquarists, bark beetle lovers, the place of Rio Poranga was also precisely located.

São Gabriel da Cachoeira is the third largest municipality in Brazil by territorial area and the second largest in the Amazon. It is also the northernmost city of the Amazon and part of its territory is located in the Pico da Neblina National Park, which covers an area of ​​more than 22,300 km2. The park is the highest point in the entire territory of Brazil and attracts tourists from all over the world who are enchanted by the tropical landscape and beauty of this place.

Submitted by
Magdalena Szubska
Approved by
Heiko Blessin & Nathan K. Lujan
1.1261111, -66.8505020
Geographical region
South America
Drainage Basin
Rio Negro
River catchment
Rio Poranga
Water body type
Water body name
Rio Poranga
Water body part
Water body course
Middle course
Water body: tributary of
Tributary name
Rio Negro

Videos above and below water

Water Chemistry

Water information

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

Chemical parameters

Dissolved Oxygen
40 %

Substrate in nature

Stone form
Submerged terrestrial vegetation

Aquatic Biotope

Date of collecting
October 2018
Collecting area
Water depth
Air temperature
34 °C
Full sun


Surrounding area

Pico da Neblina National Park, where which Rio Poranga is located, is characterized by a large variety of habitats due to vegetation (from 100 to 3014 m above sea level) and a mosaic of soils with a predominance of lowland, primeval tropical forests making up the ecosystem.

As part of ecological studies of primates, an inventory of trees in the lowlands of the Park was carried out. 2 hectares of forest were inventoried in a 500 hectare research area. The sample included 1,569 trees with dbh ≥10 cm (minimum 229 species in 45 families). The tree species Eperua leucantha and Hevea cf. brasiliensis, forest was dominant, which constituted 29% of the examined trees.

Underwater landscape

The biotope shows the typical habitat of Corydoras duplicareus. Their underwater world in this river is the color of lightly brewed tea. It is not typical black water like in Rio Nego, but the water has a warm shade.

There is not much vegetation in this area due to the shade. There are many fallen leaves, such as palm leaves, and the remains of organic plants, including fruits and roots. There are many submerged roots of trees and shrubs growing in the Theopic forest, which gives this place a very specific and exotic character.

At the bottom you can see river sand and sunken pieces of wood of various sizes. Dark but quite transparent water, slightly shaded water reveal the full range of colors of fish living in these areas.


  • Corydoras duplicareus
  • Hyphessobrycon epicharis
  • Paracheirodon axelrodi
  • Brachyrhamdia rambarrani


  • Eleocharis acicularis
  • Echinodorus grisebachii
  • Mirophyllum brasiliensis
  • Cabomba caroliniana
Threats to ecology

Water resources in the Amazonia area affect all natural and human-altered ecosystems in the region, including their human populations. Evapotranspiration by the Amazon forest provides water vapor that is transported by wind to other regions of Brazil and to neighboring countries. The enormous quantities of water involved in hydrological processes in Amazonia give great importance to the region’s water resources and to potential impacts if these cycles are altered.

The diversity of fish and other aquatic organisms is enormous, as is the importance of this fauna as economic and food resources for the human population. There are impacts from pollution, including mercury methylation in hydroelectric reservoirs. Dams also block migration of fish and alter the flooding cycles of rivers. Hydroelectric dams release methane, thereby contributing to global warming.

The chemical characteristics of different types of water affect processes such as the transport of organic carbon, the supply of nutrients to the plankton that are the base of the food chain in aquatic ecosystems, and the quantity of bio-available ions that affect sensitivity of organisms to copper and other toxic elements. Several of the major rivers in the region drain more than one country.

The Amazonian forest is gradually declining in virtually every area, many square kilometers of forest have been cleared over the last century, most of them in recent decades. This was due to many factors.

First of all, burning forest areas and their legal and illegal cutting. The land obtained in this way is intended for new pastures for cattle, soybean, maize, sugar cane and oil palm (for biofuels).

Destruction is also caused by expanding cities and large investments, such as the construction of power plants or mines that exploit local natural resources, including oil.

Global warming is also destroying the fauna and flora of the Amazon. Scientists believe that a rise in global temperature of more than 2°C above pre-industrial levels will result in catastrophic flooding and drought, rising sea levels, and heat waves and epidemics.

The importance of the Amazon for the Earth’s climate cannot be underestimated. Keeping temperatures on our planet at the right levels is not only important, it is also a sufficient source of freshwater to influence ocean currents, and its lush vegetation absorbs the most carbon dioxide in the world. In turn, the destruction of such a large area of wet equatorial forests will make it impossible to maintain the global temperature at a level that would prevent natural disasters.

The result of these phenomena is the destruction of biodiversity and the extinction of many species of plants and animals. Indirectly, it affects the quality of life of all of us, because it stabilizes the Earth’s climate and affects the weather by regulating rainfall and evaporation of water from the soil.

Millions of animals, especially from the Amazon, are illegally sold in Brazil and abroad, illustrates the Wildlife Trafficking in Brazil report, supported by USAID, through the Wildlife Trafficking Response, Assessment, and Priority Setting (Wildlife TRAPS) project.

River turtles, fish, jaguars, and birds are the most frequently poached in the Amazon region. According to the seizure data between 2012 and 2019, the largest illegal wildlife trade in the Brazilian Amazon, by volume, is the smuggling of river turtle eggs. They are used as decorative items (shells), and for culinary purposes.

Over 30 ornamental fish species were trafficked to meet regional and international demand. In these seven years, Tetra-cardenal, Silver Arowana, and critically-endangered Zebra Pleco were among the most seized.

For consumption, the pirarucu, one of the world’s largest freshwater fish species, is the principal target for poaching and trafficking.  The report points out that lack of quality data and difficulty coordinating monitoring of illegal commerce conceal the extent of illicit trade.

To reduce illegal wildlife trade, the study offers several recommendations, including developing a national strategy to combat trafficking, enhanced data collection and shared information across agencies, to strengthen environmental crime legislation.

Riparian zone

Trees near the aquatic habitat
Many - Hevea Species brasiliensis
Trees near the aquatic habitat
Many - Oenocarpus bataua