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Sidearm to Lower Rio Usumacinta, Mexico

Sponsored by
Educated by Nature

Mexico, Tabasco, Biosphere Reserve Pantanos de Centla

The Rio Usumacinta drainage system is the largest in Mexico. The Rio Usumacinta has a rich history, and served as an important trading link between the Aztec in the west and the Maya in the Yucatan. The nearby area of the river actually underwent a very early human land-use change due to agriculture. As the spanish colonized the area, nature re-established in much of the area. Later, modern industry and agriculture since removed much of the jungle again.

The area around the river is estimated to have 59% forest, 30% cropland, 7% grassland, and 3% developed. The forest covering the Rio Usumacinta is mostly jungle and mangroves. The Rio Usumacinta is both rich in flora and fauna. According to studies in the area, the river contains at least 74 different species of freshwater fish.

Submitted by
David Nørholm
Approved by
Juan M. Artigas Azas & Jairo Arroyave
GPS
18.3007946, -92.4403610
Geographical region
Central America
Drainage Basin
Usumacinta-Grijalva
River catchment
Rio Usumacinta
Water body type
Rio
Water body name
Usumacinta
Water body part
Channel
Water body course
Lower course
Water body: tributary of
River
Tributary name
Grijalva

Videos above and below water

Water Chemistry

Water information

Water type
Fresh water
Water color
Clear water
Water transparency
High
Concentration of sediments
Medium
Water temperature
27 °C
Water flow/curent
Strong

Chemical parameters

pH
7.5
Conductivity
GH
KH
Dissolved Oxygen
9 %

Substrate in nature

Sand
Beige
Pebble/Gravel
Mixed
Stone
Beige
Stone form
Roundish
Silt/Mud
Leaves
Many
Driftwood
Many
Submerged terrestrial vegetation
Yes

Aquatic Biotope

Date of collecting
04/07/2021
Collecting area
River bank
Water depth
1,0m
Air temperature
Sunlight
Full sun

Environment

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

In the jungle, along ancient Mayan ruins and tropical birds and monkeys, you find a little sidearm to the massive Rio Usumacinta. Dense jungle surrounds the riverbank of this small arm of the lower Rio Usumacinta.

The forest is massive and threes and other vegetation stretches all the way down to the water surface.

The Rio Usumacinta is located in a very biodiverse area, reported to have more than 3500 different species of plants and more than 74 different species of freshwater fish. Along this small arm of the river there is a vast amount of different species as well. The area is also inhabited by a lot of different animals such as parrots, monkeys, turtles and a few different Caiman species.

Underwater landscape

The water here is very clear, and the visibility is good. At least at this time of year. The landscape is dominated by a vast amount of driftwood, logs, branches and leafes caused by the dense surrounding jungle. All this submerged jungle material creates a new underwater jungle, with a beautiful maze of different types of trees. Along all the logs, driftwood, branches and river stones, there is also sporatic and persistent aquatic vegetation. In some areas there is also floating plants, creating cover for different types of fish.

Fishes:

  • Poecilia velifera (Poeciliidae)
  • Thorichthys meeki (Cichlidae)

Aquatic plants:

  • Vallisneria americana (Hydrocharitaceae)
  • Myriophyllum heterophyllum (Haloragaceae)
  • Ludwigia repens (Onagraceae)
  • Salvinia auriculata (Salviniaceae)
  • Egeria densa (Hydrocharitaceae)
  • Ceratophyllum demersum (Ceratophyllaceae)
  • Ludwigia repens (Onagraceae)
Threats to ecology

Although the Rio Usumacinta include some of the most remote areas of Mexico, the river is still impacted by anthropogenic activities. Deforestation is occurring in upper part of the river. Future plans to build large hydroelectric dams are also threats to the ecology.

However, modern industry, exemplified by the petroleum industry, has probably created the most substantial damage. Oil pipelines and canals have drained many wetlands, and dredge waste has created topographic barriers that alter wetland hydrology.

Riparian zone

Trees near the aquatic habitat
Many - Bucida buceras (Combretaceae) Inga vera (Fabaceae) Haematoxylum campechianum (Fabaceae)

Bibliography

Sitography

→ https://d197for5662m48.cloudfront.net/documents/publicationstatus/30162/preprint_pdf/de5c97ec61ee9687783808121115850c.pdf
→ ile:///Users/davidnorholm/Downloads/Dialnet-WaterQualityOfTheGrijalvaRiverOnTheChiapasTabascoB-6400800.pdf

Comment by the expert

Juan M. Artigas Azas: There are some minor errors in the description, but most importantly Poecilia velifera does not inhabit the Usumacinta River basin. There is a highly incomplete list of species found in the habitat.

Jairo Arroyave: Photo- and videographic documentation relied on apparently a third-party source (video “pesca con arpón”) which in my opinion did not really capture the essence of the underwater and above water habitat. Also, one of the links did not even open. Overall there was a very limited number of sources used. The list of fish species is insufficient; only 2 species are listed, while in the video you can see fishermen catching at least 3 different species, not to mention that this river has a much higher diversity of fish species, many which could have been mentioned as part of the BIN description.