The Amazon River: Lifeblood of the Rainforest
Rivers have long epitomized the spirit of adventure, providing a means of travel deep into the heart of the diverse environments that flourish around them; and few more so than the Amazon. Its waters are the lifeblood for a rainforest that covers 40% of Brazil; and the river itself flows through six countries during its 6,400 kilometre journey across the continent of South America.
The Amazon is so wide that no bridge can cross it; and it grows even wider during the floods caused by the melting snows at its source in the Andes Mountains. The distance between the two riverbanks can reach as high as 40 kilometers in some cases.
Before roads, rivers were the most efficient means of transporting people and goods. The Amazon is still used for this purpose, and not just by indigenous cultures. The city of Iquitos in Peru can only be accessed by river or air, making it the largest inland city in the world that is still inaccessible by road.
How the River was Formed
The area around the Amazon forms a natural drainage basin - a massive geographical bowl that draws all water to a single point; and it's almost twice the size of any other such drainage basin in the world.
Combine this with a tropical climate that sees an average 250 of days of rainfall a year, and it's clear why such a diverse ecosystem has been able to thrive in the region, despite the ground not being particularly fertile (the top two inches of the soil contains 99% its nutrients).
Millions of years ago, the Amazon actually flowed west into the Pacific Ocean, rather than east into the Atlantic. This was back when South America - together with Antarctica, Africa, Australia and India - formed part of a super-continent called 'Gondwanaland'.
When this landmass began to split, South America drifted into the Pacific tectonic plate. The collision brought about the formation of the Andes Mountains, which blocked the river's passage and created a large lake in the process.
So for a long time, the Amazon was a lake rather than a river. But the earth continued to reform itself, and eventually the water broke through the barriers and surged forth into the Atlantic ocean, flooding all in its path and becoming the river we know today.
Now it runs from its source high in the Andes mountains towards the Atlantic, where it spills into the ocean with such force that it's about 230 kilometres before the water of the river begins to mix with that of the ocean. Hence why ships approaching the river mouth (which is large enough for ocean-going vessels to pass through) can tell they are nearing their destination long before the coast of South America is in sight, as the sea water begins to take on the same brownish colour as that of the Amazon.
Whether or not the Amazon is longer than the Nile may be a point of contention, but there's no debate about which has the greater volume of water. 20 per cent of all freshwater that is discharged into the ocean comes from the Amazon, as does 20 to 25 per cent of all water that runs off the earth's surface.
The People of the Amazon
The livelihoods of over a hundred indigenous tribes – many of which have had no contact whatsoever with the outside world – are dependent on the Amazon. They include the Waodani tribe, who speak a language that has no linguistic links to any other known dialect; and the Tagaeri tribe, who are so determined to preserve their isolation that they went so far as to attack and kill two missionaries who attempted to make contact with them in 1987.
Other groups have been more open to outside influence. The ribereños are descended from a mix of European colonists and indigenous tribespeople, and though they still rely on the river for sustenance and transport, they have incorporated some aspects of modern technology into their lifestyles.
The river is the foundation of one of the world's most diverse land-based ecosystems. Often referred to as the “lungs of the earth”, the Amazon rainforest produces 40 per cent of the world's oxygen, and is home to wide range of flora and fauna including 500 mammals, 30 million insect varieties, 175 lizards, 300 other species of reptile, and a third of the world's bird species. Harpy eagles swoop down from the skies and snatch unsuspecting monkeys from the branches of the trees; while electric eels, giant catfish, turtles, crocodiles and even bull sharks lurk in the waters of the river.
Among the most famous creatures to be seen here are the pink dolphins - that is, if anyone is lucky enough to see them. Though they occasionally pop their heads up above the surface in order to satisfy their curiosity, they disappear back down below just as quickly; and any attempt by tourists to snap pictures of them usually produces numerous photos of ripples on the water's surface, where a pink dolphin had shown its face only moments before.
Though local legends may tell of the dolphins transforming into humans and walking the shores of the river at night; in general they stick to shallow waters, and thus have little trouble from predators. However, deforestation and pollution remains a massive threat to all species that inhabit the Amazon.
The Nile gave rise to a great man-made civilization, while the Amazon is the heart of a natural wonder. It may not be made by man but it can certainly be destroyed by man, if adequate measures are not taken to protect it.