AMAZON RIVER: CHARACTERISTICS, SOURCE, ROUTE, FLORA, FAUNA - GEOGRAPHY - 2025

The Amazon River is the largest river on the planet. Located in the south of the American continent, it is born in Peru at about 6,000 meters of altitude and contains branches that connect it with tributaries from Ecuador, Bolivia, Colombia, Venezuela, Guyana and Suriname, to cross Brazil and flow into the Atlantic Ocean.

Its hydrographic basin is little more than 6 million km2, which represents almost 40% of South America. Some researchers propose that millions of years ago it flowed in an easterly direction, towards the Pacific Ocean, but with the geological changes that the Earth has undergone, about 11 million years ago it changed its direction towards the west.

The river basin is characterized by being an extensive region and with virgin lands conserved for millennia. Photo: Peter Angritt

Discovery

- Pre Columbians

Studies by researcher Michael Heckenberger show that sedentary life in the jungle environment, on the banks of the river, was possible before the arrival of the Spanish. The archaeological finds show at least a walled population of approximately 50,000 inhabitants with sufficient technological development to use the river through irrigation for its plantations.

Likewise, the chronicles of Father Gaspar de Carvajal, chronicler of Orellana, bear witness to the tribes settled along the river.

- European

Americo vespucio

The Florentine Américo Vespucio was the first to come across the river mouth on a trip during the year 1499, in which he accompanied Alonso de Ojeda. There he took the opportunity to make observations of the flora and fauna, however, they did not enter the course of the Amazon.

This explorer and merchant stood out as a supplier of the merchandise of the ships that left for the Indies. Maps and descriptions of the new world are also attributed to him, for which a renowned cartographer named the new continent after him in 1507.

Francisco de Orellana

Forty-two years later, the conqueror and explorer Francisco de Orellana, began an expedition together with another Spaniard, Gonzalo Pizarro, in search of the country of cinnamon, El Dorado and perhaps a new viceroyalty. They left from Los Andes and before the failure of the excursion, Orellana decided to go ahead with some seventy men to try a nearby town.

The force of the Napo River complicated the return of the pilgrims, pushing them league by league to navigate downstream. On their way they found some friendly native villages and others not so much. When he gave up the idea of ​​going back to give notice to those who were left behind, the flow carried them through what would be the longest river on the planet.

This step took about nine months, claiming the lives of almost all the men who accompanied him and the loss of all supplies. However, they reached the mouth of the river and managed to skirt the continent in a northward direction and then return to the Kingdom of Spain. There he was imprisoned for some time until the treason complaint filed by Gonzalo Pizarro was dismissed.

On the journey, a confrontation took place in which the expedition's chronicler assured that they were fighting corpulent and very brave women, similar to the Amazons narrated by Greek mythology. And although in principle the river would bear the name of its first European navigator, Orellana, it was later changed to that of the mythological warriors, Amazonas.

Some time later, the conqueror would return together with a fleet of 4 ships, material to build other river boats and approximately 300 soldiers, including infantry and cavalry, in an attempt to go up the river to the Andes and colonize its course. It turned out to be a bumpy ride on the road, eventually passing away trying to find the main waterway.

A century later, the Portuguese Pedro Texeira, along with Jesuit friars, would be the first navigator and cartographer to travel the route taken by Orellana in an inverted manner, following the Napo River to reach Quito.

General characteristics

The Amazon travels a distance of 7,025 km, with depths that vary according to geography and can range from 20 to 50 meters, up to 90 to 100 meters in the deepest areas. The volume of its flow can vary between 80,000 and 12,0000 cubic meters of water per second. Every year, this river deposits 209,000 m ³ / s of fresh water in the Atlantic Ocean.

- Contamination

Contamination with heavy minerals as a result of oil exploitation in the headwaters of the river in Peru, is one of the main problems facing today.

Toxic waste

In a study published in 2017 with 2,951 water samples taken from 1987 to 2013, it is evidenced that for almost thirty years an average of 8 tons of hexavalent chromium, 5 tons of lead and 3.7 tons of hexavalent chromium continue to be deposited in the river. salt per year.

The exploitation of hydrocarbons also generates formation water, that is, a type of toxic water coming from the oil extraction wells containing, in this case, chloride (13,379 times more than the normal level of river waters), chromium, cadmium, lead, barium and sodium which also exceeds the natural levels of the Amazon.

This type of toxic water should return to the drilled wells or be treated in specialized plants, however, it is discharged into the Amazon, which generates high levels of risk to the health of those who still use the benefits of the river. These substances have been traced up to 36 km around the operating companies.

The risks for the indigenous population, which feed on terrestrial and river fauna, are neurotoxic and carcinogenic, although there are still no specific studies in this regard that show the incidence in this population. Likewise, the highly diverse fauna of the areas surrounding the river is also directly affected.

The study, published by the journal Environmental Pollution, points out the existing concern about the chemical change that the waters of the river are undergoing at its head due to human action, a problem that could be reversible if certain strict safety and health measures were taken.

Waste and pesticides

Other causes of pollution have to do with the industrial use of the surrounding areas for coffee or soy plantations, in which pesticides are used that end up being dumped into the river, as well as hundreds of tons of solid waste per year due to the poor management of the same in peripheral communities.

Such is the case of the city of Nauta, close to the headwaters of the Amazon River. There is one of the 23 public waste dumps in the country, financed by the Spanish Agency for International Development Cooperation.

Federico Meléndez Torres, its manager, ensures that the facility receives 12 tons per day of the 16 tons of waste produced by the population. The rest goes to the river.

Others

In other research supported by the Swiss National Foundation for Science and the Center for Cooperation and Development of the Federal Polytechnic School of Lausanne, they found that arsenic levels are up to 70 times higher than those recommended by the WHO, as is aluminum and manganese.

- Relevant historical data

According to the studies of Dr. Carina Hoorn, 11 million years ago this river was transcontinental: it crossed the continent of Gondwana in a westward direction, in the Miocene. Later, with the emergence of the Andean Cordillera, she was forced to change her direction to the east in search of an exit to the sea.

It has been confirmed that its flow represents 20% of the planet's fresh water, with an average of 100,000 m ³ of water per second. And given the current of the Atlantic Ocean, at its mouth no sediments are formed.

- Comercial activity

The river basin is characterized by being an extensive region and with virgin lands conserved for millennia. Its average temperature and humidity allow the subsistence of the forest and its great diversity of species, both in fauna and flora.

The soil and subsoil are then used in different areas such as livestock, agriculture, mining, forestry and the aquifer for their economic exploitation. Some of these practices can be considered as harmful in the river system due to processes without the control of the competent authorities.

Felling

An example of this is the deforestation carried out in the basin. In the last 60 years, it has lost almost a million square kilometers, which has multiple consequences for the biodiversity of the area, for the life of human beings, the planet and the global climate balance.

Soy

Followed by logging, the soils used for agricultural plantations pose another problem facing this ecosystem. For example, in the case of Brazil, its main export item is soybeans with 12% above the timber and oil industries, among others, and represents a contribution of almost 26 billion dollars to the economy of this nation, but at the same time, the dedication of 34.90 million hectares for cultivation.

Mining production

In the case of Peru, fourth in the world in the index of mining potential, the exploitation of minerals represents 60% of the value of the country's exports, 10% of the total production of its GDP and 5% of the labor force.

In the department of Loreto, which belongs to the Amazon basin, it was found that the actions of illegal miners had destroyed 20 hectares of the forest, with the consequent mercury contamination of the Marañón and Santiago rivers, main tributaries of the Amazon River.

Others

Among other commercial activities, its use as a means to transport products extracted from the Amazon basin, the fishing activity that distributes various species of fish to the entire region, the export of livestock and agricultural products (corn, cassava, bananas and endemic fruits) can be mentioned. and loggers.

It also provides employment to a significant percentage of the population settled in both large and small cities along the river, boosting the economy and the exchange of services.

- Importance

As mentioned above, the Amazon river basin represents 20% of the planet's fresh water. It is the largest amount accumulated in a single place and, due to the climate change that is currently taking place, it has aroused a lot of interest from different organisms in favor of its conservation.

It is also estimated that the region's forest is listed as the lung of humanity, since it contains 40% of the planet's tropical forests, which generates millions of tons of carbon dioxide being transformed into oxygen thanks to the photosynthesis process.

It functions as a regulator of its own climate and it is believed that it also regulates the South American climate by cooling the earth, providing moisture and rainfall, preventing erosion and purifying water. It should be noted that, although it only covers 1% of the planetary surface, it conserves 10% of the wild species that are known.

According to figures published by the UN, 33 million people live in the river basin, distributed around 380 indigenous communities who speak 86 different languages ​​and 650 dialects. So, in addition to its natural, economic and environmental importance, it is also necessary to highlight the importance it represents for its inhabitants.

- Tourism

The countries over which the Amazon river basin extends have had tourist infrastructure for those who wish to enter the life of the tropical forest. In Ecuador, Colombia, Brazil and Peru it is possible to discover offers that promise adventures with unrepeatable landscapes.

Jungle tour activities, river navigation, contact with animals rescued from hunting, flights, contact with indigenous communities and their traditional activities, consumption of food typical of the region, sighting of endemic fauna and disconnection from noise and City pollution are part of the promises of different tourist agencies that operate in the area.

Birth

The length of the river is considered from the last measurements made in 2007. The Limeña Geographical Society affirms that the river is born in the Apacheta Creek, about 5,170 meters above sea level in the department of Arequipa, and then travels a part of Peru, another of Colombia and cross Brazil to the Atlantic.

Route and mouth

Initial section

From the slopes of Nevado Quehuisha, in Peru, it crosses the department of Loreto to go through the relevant port of Iquitos, then Caballococha and finally Santa Rosa del Yaraví, while its channel directs it to the north of the continent, making it pass through the border with Colombia. and touch the important port of Leticia.

Middle section

After the triple border between Peru, Colombia and Brazil, further on it joins the Negro River, where the dark coloration of this tributary can be appreciated without mixing with the brown waters characteristic of the Amazon sediments for a good stretch.

Final stretch

The final section could be considered as the route from the port of Manaus to the Atlantic Ocean, passing through Macapá and Santarem. This last route is done through plateaus in the form of terraces for around 240 km in length, which makes navigation difficult.

Main cities that travels

Historically, the river has served as a source of life for many populations since long before Francisco de Orellana's discovery. At present, some eleven cities remain active on the banks of the river, taking advantage of the commercial activities for which they subsist.

In Brazil, the cities with the most population are Manaus, with a total of just over two million people; and Belem, also with a population that exceeds 2 million inhabitants.

One of the attractions for tourists is the free port that operates in the first city, as well as its geographical location. While in Peru the most populated city located on the river bank is Iquitos, with almost half a million inhabitants. Brazilian cities are the oldest founded in the region.

In general, the inhabitants of the riverbanks belong to different and varied aboriginal ethnic groups, who have maintained their natural connection with the Amazon rainforest over the centuries. But the life of cities is increasingly present in the dynamics of daily life.

On the other hand, there is a population of settlers and their descendants, among whites, mestizos and indigenous people also settled on the banks of the river who prefer the city to live.

Tributaries

Being such an extensive hydrographic basin, the Amazon River receives water from multiple convergences, some more mighty than others, but it could be ensured that its waters are made up of rivers from the nine countries that make up the basin and that feed its main tributaries.

Among the most important can be counted, from Peru the Marañón River and the Ucayali, from Ecuador the Napo River, where Francisco de Orellana descended; from Colombia the Putumayo and Caquetá rivers, from Bolivia the Madre de Dios river and from Brazil the Negro river, the Tapajós river, the Xingú river and the Madeira river.

Flora

Because the rainforest floor receives very little sunlight and the space to grow is very limited, each tree in the ecosystem becomes a carrier of plants that grow on it to benefit from the sun's rays. At present, researchers have not stopped discovering new species of plants, although they already exceed 60,000 plant species.

According to studies, the trees can average about 16,000 species, the most common being the Euterpe precatoria, the Cupressus lusitánica, the Protiumaltissimum and the Eschweilera coriacea, very tall, leafy and large trees. On them live other plants that seek the benefit of sunlight.

These plants are called epiphytes and adapt to trunks, leaves, branches and can even grow on other epiphytes. Among them are orchids, bromeliads, ferns, cacti, mosses, araceae, and lichens.

Orchid flowers tend to have a longer life than others, which is why they are highly valued among horticulturists around the world. Another interesting fact is that in the Amazon alone there are more than 20 thousand species of this group of plants with different colors, shapes and sizes.

Bromeliads are also usually very striking due to the colors of their leaves. These grow around the stem and therefore can hold several liters of rainwater. Thus, different specimens of insects and aquatic species such as amphibians find a safe place where they can reproduce and provide themselves with the vital liquid. Then when they die they become a source of energy for the plant itself.

Fauna

On the other hand, the Amazon fauna encompasses 80% of the existing class diversity in the world, according to researchers from this territory, cataloging some 326 species corresponding to 67 mammals, 326 birds, 28 reptiles, 36 amphibians. and 185 fish.

Mammals

Luis Miguel Bugallo Sánchez

Among the best known are monkeys, highlighting the spider monkey, the flying saki monkey, the tamarind monkey, the marmoset, howler monkey and the pink dolphin. Of the felines, the jaguar, puma, panther, anteater and a great variety of bats stand out.

Birds

Among the most common birds to spot are the toucan, the woodpecker, the squirrel cuckoo, the blue and yellow macaw, the alikobalt parakeet, the yellow-faced parrot, the Zimmer nuthatch and hummingbirds.

Fishes

One of the most representative fish in the Amazon is the piranha fish, whose teeth are so sharp that they can separate the meat from the bone in just seconds. They are attracted to the smell of blood and their favorite food is manatees and anacondas. The world's largest freshwater fish called Piracurú and the famous electric eel are also found here.

Reptiles

There are three species of turtles: Podocnemiserythrocephala, Podocnemissextuberculata and Podocnemisunifilis, all endemic to the territory, as well as the crocodile Paleosuchustrigonatus, known as the second smallest species of this reptile in the world.

References

1. Oil pollution in the Amazon is changing the chemical composition of water, University of Barcelona, ​​published in July 2017. Taken from uab.cat.
2. Possible and sustainable Amazon, article published by ECLAC. Taken from cepal.org
3. The bad habit of dirtying the Amazon, published in the newspaper El País in Spain, April 2018. Taken from elpais.com.
4. Contamination of the Amazon: Who is behind the destruction of the world's largest rainforest ?, RT, June 2018. Taken from actuality.rt.com.
5. Amazon Fires: 3 Reasons This Region Is So Important (Even If It Isn't Really 'The Lung Of The World'), BBC News, August 2019. From bbc.com.