Maquari Creek, Rio Branco basin, Brazil

Environment

Environment

Untouched

Surrounding area

The area surrounding Maquari Creek is situated within the Rio Branco drainage of Roraima, northern Brazil, forming part of the greater Amazon Basin. The creek originates above a shallow floodplain lake and flows through a landscape dominated by tropical lowland rainforest. Dense riparian vegetation lines the banks, providing shade and contributing large amounts of organic material to the aquatic environment. Philodendrons, bromeliads, and orchids are common components of the surrounding flora, while fallen trees, submerged branches, and root tangles create complex habitat structure both above and below the waterline.

Seasonal fluctuations in rainfall and water levels strongly influence the landscape. During periods of higher water, parts of the forest margin become inundated, creating temporary connections between terrestrial and aquatic habitats. Sandy substrates dominate the creek bed, with fine silt accumulating in slower-flowing areas along the banks. The clear water and structural complexity support a diverse assemblage of aquatic life typical of the Rio Branco region.

The surrounding ecosystem is rich in wildlife. Numerous bird species, including kingfishers, toucans, macaws, festive parrots, and black vultures, are regularly observed in the area. The adjacent floodplain lake supports populations of caimans, while the Rio Branco and its tributaries provide habitat for a wide variety of fishes. Despite limited human activity, such as occasional fishing and boat traffic in nearby waters, the creek itself remains largely natural and retains the ecological characteristics of a relatively undisturbed Amazonian clearwater habitat.

Fish:

• Pterophyllum leopoldi (Cichlidae)
• Pterophyllum scalare (Cichlidae)
• Apistogramma agassizii (Cichlidae)
• Apistogramma sp. (Cichlidae)
• Dicrossus filamentosus (Cichlidae)
• Mesonauta insignis (Cichlidae)
• Satanoperca lilith (Cichlidae)
• Heros notatus (Cichlidae)
• Crenicichla sp. (Cichlidae)
• Crenicichla johanna (Cichlidae)
• Rineloricaria fallax (Loricariidae)
• Copella sp. (Lebiasinidae)
• Hemigrammus sp. (Characidae)
• Hyphessobrycon copelandi (Characidae)
• Hyphessobrycon bentosi (Characidae)
• Acestrorhynchus falcatus (Acestrorhynchidae)
• Brycon sp. (Bryconidae)
• Potamotrygon sp. (Potamotrygonidae)
• Chilodus punctatus (Chilodidae)
• Nannostomus sp. (Lebiasinidae)
• Moenkhausia sp. (Acestrorhamphidae)
• Biotodoma cupido (Cichlidae)
• Hemiodus gracilis (Hemiodontidae)
• Lugubria lenticulata (Cichlidae)

Terrestrial vegetation:

• Philodendron sp. (Araceae)
• Bromeliaceae (Bromeliaceae)
• Orchidaceae

Underwater landscape

The underwater landscape of Maquari Creek is characterized by a predominantly sandy substrate interspersed with areas of fine silt deposition in slower-flowing sections along the banks. The creek bottom is uneven, with shallow depressions, submerged root systems, and accumulations of leaf litter creating a mosaic of microhabitats. Fallen trees and dense tangles of submerged branches are abundant throughout the creek, providing shelter, spawning sites, and feeding areas for a variety of fish species.

Water clarity is generally high, allowing sunlight to penetrate the shallow channel and illuminate the pale sand below. In contrast to the open substrate of the central channel, the margins are structurally complex, containing submerged bushes, woody debris, and deposits of organic matter. The combination of sand, silt, roots, and branch tangles creates a highly diverse habitat that supports both open-water and structure-oriented fishes. At ideal water levels, the creek reaches depths of approximately 1.5 metres, offering excellent underwater visibility and revealing the intricate interaction between the creek’s physical structure and its aquatic fauna.

Threats to ecology

Although Maquari Creek remains largely natural and relatively undisturbed, several potential threats exist within the wider Rio Branco drainage. Localized human activity has been observed in adjacent waters, including the use of gill nets for food fishing in the floodplain lake connected to the creek. Food scraps discarded from boats on the Rio Branco have also been observed attracting scavenging birds such as black vultures and caracaras, indicating a degree of human presence within the ecosystem. In recent years, recreational sportfishing operations targeting peacock bass have also appeared in the region, although these activities have not been reported from the creek itself.

Changes in land use elsewhere within the basin, including deforestation, agriculture, mining, and infrastructure development, may alter water quality, sediment loads, and natural hydrological cycles over time. Climate variability represents another significant concern. Extreme droughts and unusually low water levels have already affected access to the creek in some years, reducing available aquatic habitat and altering environmental conditions. As part of the Amazon Basin, the creek is also vulnerable to broader environmental pressures such as climate change, habitat fragmentation, and biodiversity loss. Continued conservation of the surrounding rainforest and maintenance of natural river dynamics are essential for preserving the ecological integrity and biodiversity of this unique clearwater habitat.

Riparian zone

Trees near the aquatic habitat

Many -

Bibliography

• → Universidade Federal do Ceará (UFC) – Centro de Ciências, Departamento de Geografia, Fortaleza. - Caracterização Hidrogeomorfológica da Bacia Hidrográfica do Rio Branco, Estado de Roraima, Brasil by Thiago Morato de Carvalho
  
• → Geografias - Aspectos hidrogeomorfológicos do sistema fluvial do baixo rio Uraricoera e alto rio Branco como subsídio à gestão de terras by Thiago Morato de Carvalho & Roseane Pereira Morais
  
• Exchange with Jackie Anderson
  

Sitography

Comment by the expert