The longest winding waterway in South America: the Amazon

In 1541, the Spanish soldier Francisco de Orellana was the first European to explore the Amazon. After witnessing pitched battles with tribes of female warriors whom he likened to the Amazons of Greek mythology, the river was given its name, ‘ the Amazon’ or ‘Amazonas’ in Spanish and Portuguese. Although the name is typically employed for the entire river, in Peruvian and Brazilian nomenclature it properly is applied only to sections of it.

Its length

The Amazon is the longest river in South America and it runs through Guyana, Ecuador, Venezuela, Bolivia, Colombia and Peru. The total length of the river is at least 6,400 km, which makes it slightly shorter than the Nile River. Within 160 km of the Pacific Ocean is its westernmost source, high in the Andes Mountains. Its mouth is in the Atlantic Ocean, on the north-eastern coast of Brazil. The length of the Amazon has been a subject of debate since the mid- 20th century and some experts believe that the Amazon River is actually the longest in length, longer than the Nile.

In 2007 an expedition travelled to the region of Carruhasanta and Apacheta creeks in an attempt to determine what was the “true” source of the Amazon and they concluded that it was the Apacheta Creek. The team then proceeded to meas- ure the river’s length and according to their calculations, the final measurement for the length of the Amazon— from Apacheta Creek to the mouth of Marajó Bay—was about 6,992 km.

Its water body

Considered to be the largest river by discharge of water in the world, it expels about 209,000 litres of water per second. The average discharge of the river is greater than the next seven largest independent rivers combined. The Amazon River pours 1/ 5th of the worlds freshwater into the Atlantic, unsurprisingly due to its tremendous flow. 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.

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.

The Amazon basin

The Amazon basin is a great structural depression, a trough that has been filling with immense quantities of sediment, and it is the largest drainage basin in the world. Stretching some 2,780 km from north to south at its widest point, the basin includes the greater part of Brazil and Peru, significant parts of Colombia, Ecuador, and Bolivia, and a small area of Venezuela; roughly two- thirds of the Amazon’s main stream and by far the largest portion of its basin are within Brazil. The river is not building a delta because most of the estimated 1.3 million tons of sediment that the Amazon pours daily into the sea is transported northward by coastal currents to be deposited along the coasts of northern Brazil and French Guiana.

Amazon floods

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. The floods of the Amazon are not disasters but rather distinctive, anticipated events. Their marked regularity and the gradualness of the change in water level are due to the enormous size of the basin, the gentle gradient, and the great temporary storage capacity of both the floodplain and the estuaries of the river’s tributaries.

Its 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.

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. 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 piranha and the anaconda are the first to come to mind when thinking about terrorizing creatures of the Amazon River, yet both are actually quite harmless to humans. However, resembling an alligator, 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. 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. You will also find the highly adaptable Bull Shark in the Amazon River, since it has the ability to acclimatize to various degrees of water salinity. 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.

When to visit

If seeing the lush Amazon rainforest and getting up close to lots of birds and mammals sounds most attractive, then December to May might be your best choice.

If jungle hikes and spotting exotic migratory birds perched on trees between flights across Amazonia appeals most to you, while still having the chance to see capuchin monkeys, kinkajou, and other mammals, and going on great fishing expeditions, you might be happier choosing the warmer, low water season of June through November. Ayeshni Wickramasinghe