Major Brazilian river basin under threat from farming, mining, and climate change

The Tocantins-Araguaia basin is the largest river basin located entirely within Brazil. Comprising the Tocantins and Araguaia rivers and cutting through six states in the country’s North and Center-West regions, it is among the most predominant hydroelectric energy sources in Brazil. What’s more, the majority of its rivers are navigable, making it of extreme importance to the local economy, transporting products and people around the region.

However, the extraction of minerals — including iron ore, manganese, copper, gold, nickel, among others — and the expansion of agriculture have degraded the river basin, not to mention the constant factors of deforestation, logging, hunting, and fishing.

The basin’s rivers have become progressively more polluted and full of sediment, largely due to the chemical products used in the mining industry. As a result, fish are dying at an alarming rate, and riverside communities who rely on the natural wealth of rivers and forests have seen their health and quality of life deteriorate.

In a recently published study in scientific journal Environmental Management, a group of 58 Brazilian researchers surveyed all of the threats faced by the Tocantins-Araguaia river basin. Many...