Fascinating Facts About the Amazon River

Learn all about the mightiest river in the world and one of the most popular destinations in South America, with these 10 Fascinating Facts About the Amazon River

South America’s Amazon ecosystem is often described as ‘larger than life’ and indeed it comprises the most expansive rainforest in the world, home to the second-longest river on earth. Combined, they spawn an incredible amount of life, with the sheer abundance of flora and fauna making it an essential breeding and feeding ground. A passionately protected yet endangered bionetwork, the Amazon River and Rainforest provide our planet with indispensable oxygen, fresh water, and biodiversity.

sunset over a lake

Sunset over the Amazon River. Photo credit: Pixabay.

An intensely studied natural wonder, the Amazon continues to astonish scientists. Only a few months ago, a colossal coral reef was discovered in the Amazon River, leading the world to wonder just how many secrets this magnificent part of the world has yet to reveal.
Here are 10 Fascinating Facts about the Amazon River you ought to know!

1. The Amazon River used to flow in the opposite direction

Up until 15 million years ago, the Amazon River used to flow into the Pacific Ocean, but the formation of the mighty Andes mountain range caused it to become landlocked. It took almost 5 million years for freshwater lakes to be formed, and for the river to once again find its outlet into an ocean. Only this time, it started pouring into the Atlantic. Nowadays, the Amazon is the largest river in the world by water flow, pouring out an astonishing 12,540,000 cubic meters of water every minute.

aerial view over the Amazon river.

The Amazon River as it snakes its way through the Amazon Rainforest. Photo credit: Rainforest Trust.

2. There are no bridges built across the Amazon River

Unlike the Nile, which is over 480km longer, the Amazon River boasts no bridges at all. Framed by virgin and quite impenetrable rainforest, the shores of the Amazon have never been built up, so the only way to cross it is by boat. In 2010, the first bridge was built in one of the Amazon tributaries (Rio Negro) in the popular tourist host-spot of Manaus. This was the first bridge ever built in the entire Amazon River system, which boasts more than 1,100 tributaries, and is one of the most complex and extensive in the world.

boat over brown river

Boat ride across the Amazon River. Photo credit: Pixabay.

3. The Amazon River is home to a dolphin that blushes itself pink

The Amazon River is a phenomenal breeding ground for countless endemic creatures. Among the many beautiful Animals to Spot in the Amazon is the boto, the largest dolphin in the world. A highly protected species, the Pink River Dolphin – as it is more commonly known – can be found frolicking in the Amazon basins in Bolivia and Peru. On an adventure tour to Rurrenabaque or unforgettable river cruise in Iquitos, you can indulge in a canoe trip to spot the last remaining botos in the Amazon. At first glance, the boto appears light grey in colour, yet when it gets excited it blushes a soft hue of pink. Moreover, as they age, their skin becomes more transparent, allowing blood flow to be more visible. The abundance of wilderness in the world’s largest rainforest is what makes the Amazon such an ideal family vacation destination.

river dolfin with leaf in mouth

The Amazon River Delphin. Photo credit: Michelle Bender.

4. The Amazon River supplies the earth with 20% of its freshwater supply

Not surprisingly given its tremendous flow, the Amazon River pours 1/5th of the world’s freshwater into the Atlantic. At its exit point, the Amazon freshwater greatly dilutes the salinity of the ocean, and the colour difference persists over an area of 2.5 million square kilometres. In total, the Amazon discharges more water into the oceans than the next 7 largest rivers, and it is at this very confluence that the thriving coral reef has been discovered.

Yellow water with blue sky

Where freshwater meets sea water the confluence of the Amazon River and the Atlantic Ocean. Photo credit: Lance Willis.

5. A river which flows beneath the Amazon River has just been discovered

Geologists believe that there is an underground river which follows the path of the Amazon River for its entire length, approximately 6,000 kms. The Rio Hamza was discovered by Brazilian scientists just a few years ago. It appears to flow up to 4km underground and is allegedly “hundreds of times wider than the Amazon River”.

bamboo houses on river

Houses on stilts along the Amazon River. Photo credit: Aliman5040.

6. The Amazon River & Rainforest are home to 30% of our planet’s flora and fauna

Collectively, the Amazon River and invaluable Amazon Rainforest are home to more than 40,000 species of flora, 2,000 species of fish, over 400 species of both mammals and amphibians, almost an equal number of reptiles and 2.5 million insects.

7. The Amazon River and Rainforest flood every year

The main source of water for the Amazon originates from Andean ice melt. Every year between June and October, as the ice melts, the Amazon River overflows and consequential water levels can rise between 9 and 13 metres. As the river floods the rainforest, and combine with extensive rains, they create so-called varzeas, or “flooded forests”. During the rainy season, the river can quadruple in width.

flooded fields in the amazon

Flooded Amazon. Photo credit: Aljazeera.

8. The Amazon Rainforest & River receive much-needed nutrients…from Africa

Like two worlds combining to create an ideal ecosystem, the Amazon ecosystem is annually fed by blowing sands of the Sahara Desert. The rainforest and river rely on this input of valuable minerals to keep them lush and fertile. A NASA satellite was used to track Saharan sand as it made its way across the Atlantic to reach the Amazon Rainforest.

9. The largest and most feared predator in the Amazon River is the Black Caiman

Mention ‘terrorizing creatures of the Amazon River’ and most people will immediately think of only two animals: the piranha and the anaconda. Granted, neither one of those two elicits warm, fuzzy feelings, yet both are actually quite harmless to humans. The Black Caiman? Well…that’s another story. Resembling an alligator (only far bigger and scarier) the Black Caiman is the largest predator living in the river system, one which feeds on just about anything with a heartbeat. Luckily, however, attacks on humans are very rare. If anything, it’s the caiman who should feel threatened. Almost hunted to extinction for its valuable skin, the Black Caiman is now a fiercely protected species, and numbers are on the rise yet again.

Black Caiman in River

Black Caiman. Photo credit: Leonardo C. Fleck,

10. The most unusual animal to live in the Amazon River is the Bull Shark

Believe it or not, the Bull Shark is one of the most adaptable of its kind and has the ability to acclimatize to various degrees of water salinity. So much so, that quite a healthy number of Bull Sharks have been found to meander through the Amazon River, as far away from the sea as 4,000km.

shark under water

Bull Sharks… not only a threat at sea. Photo credit: Pterantula.

Want to experience one of our planet’s most astonishing destinations? Then join us on an Amazon cruise and explore some of the most inaccessible corners of this glorious natural wonder. Swim with dolphins, dodge black caimans, and be awe-struck by the inherent beauty of the magical Amazon River. We offer bespoke tours aboard luxurious river boats, and include overnight stays in charming eco-lodges built along the shores of the Amazon River in Brazil, Peru, Bolivia, and Ecuador. Don’t wait any longer and go on a South America Adventure! Click here for more information about Chimu.

Author: Laura Pattara

“Laura Pattara is a modern nomad who’s been vagabonding around the world, non-stop, for the past 13 years. She’s tour guided overland trips through South America and Africa, travelled independently through the Middle East and is now in the midst of a 5-year motorbike odyssey from Germany to Australia.”