Damage from Gold Mining in the Amazon – Madre de Dios, Peru

We used to think only big commercial mining operations could have a significant environmental impact.  These images gave us a schooling.  The cumulative impact from many small, artisanal mining operations can result in just as big a mess as a conventional open-pit mine.  As reported in The Guardian and captured on video by the Carnegie Institution for Science, mercury contamination from illegal and unregulated gold-mining sites in the Madre de Dios region of Peru is flowing downstream and polluting the water sources that indigenous people depend on:

Aerial view of many small-scale artisanal gold-mining operations in the Madre de Dios region of the Peruvian Amazon. Source: The Guardian.

A Landsat-8 satellite image taken in April 2013 clearly shows the landscape disruption associated with mining activity, spanning an area over 11 miles long and up to 4 miles wide. Sediment-laden runoff in this area of high rainfall (it is a rainforest, after all) is rushing uncontrolled into adjacent rivers, coloring them pale muddy brown:


Landsat-8 satellite image taken in April 2013, showing landscape impact of illegal gold mining operations and sediment-laden runoff in adjacent rivers – a harbinger of the mercury contamination affecting indigenous people downstream. Intact forest is dark green. Land cleared for agriculture or by logging is pale green.


Measurement of the area impacted by mining; this does not include adjacent areas of deforestation (pale green) that probably indicate rapid settlement and farming accompanying the influx of miners.

Stepping back a bit, a higher-elevation view clearly shows the downstream transport of sediment — possibly contaminated with mercury — from the mining area:

Vertical overview of mining area and downstream transport of pale brown sediment (north is to the right in this view).


Panoramic view toward the north, overlooking the active gold-mining area (foreground) and showing sediment runoff downstream. Landsat-8 satellite image taken in April, 2013.