For decades, wounds have surfaced in the Peruvian Amazon where the Rio Inambari merges with the Rio Madre de Dios, carving thick gashes into ancient tree stands. These almost lunar scars of barren rubble were formed at the hands of a growing enterprise capitalizing on gold that the rivers deposit throughout their floodplains.
A new study published in Environmental Research Letters shows that the spread of this devastation has quickened and increasingly affected a unique Amazonian ecosystem. Peatland swamps safeguard meters-deep deposits of carbon accumulated over millennia and contain unique assemblages of life distinct from the surrounding rain forest.
Around 15 years ago, “there was mining in peatlands, but it was the exception.”
Around 15 years ago, Ethan Householder first visited the Madre de Dios region, where 70% of artisanal gold mining takes place in Peru. Peatlands are dispersed in small pockets throughout the enormous Madre de Dios floodplain, which stretches into Bolivia, where the river’s confluence with the Mamore forms the Madeira and eventually empties into the Amazon itself.
Householder, a community ecologist at Germany’s Karlsruher Institut für Technologie and a study coauthor, recalled that at that time, “there was mining in peatlands, but it was the exception.”
Now, he and his colleagues have found that peat mining is surging in the region.
To determine how artisanal gold mining (defined as subsistence or small scale and often illegal) has affected peatlands along the Rio Madre de Dios, the team searched through decades of satellite imagery for sudden drops in the greenness of the forest canopy that might signal deforestation. Then, they looked for spectral information indicative of mining activity: the buildup of gravel and sand, for example, and the presence of water-filled pits at the site of formerly forested land.
Using a machine learning algorithm trained to pick out pixels that met those criteria, the team combed through imagery from 1985 to 2023. They found that more than 11,000 hectares of forest along the river had been converted to mines, with most of the growth taking place since the mid-2010s.
Studies like this “are all puzzle pieces of evidence saying this is a huge issue and still not resolved.”
The analysis found more than 550 hectares associated with mining activity in peatlands. Though that’s just a fraction of the total area that’s been mined, research showed that peatland mines have expanded faster than mining in the forest at large in recent years. (Fifty-five percent of peatland loss occurred within the past 2 years.)
Already, digging up these peatlands has released anywhere from 200,000 to 700,000 metric tons of carbon stored belowground—in addition to the carbon released from the loss of trees and plant life above it. If all the peat in the Madre de Dios region is lost, some 17 million metric tons of long-sequestered carbon could be released.
Mining in the Amazonian peatlands “is basically the entire force of global capitalism on top of one of the most carbon-rich habitats on Earth,” Householder said.
The new work continues and expands the story of how gold mining is degrading the Amazon, said Greg Asner, a conservation ecologist at Arizona State University who has been studying the effects of gold mining on the Peruvian Amazon since the early 2010s. To him, studies like this “are all puzzle pieces of evidence saying this is a huge issue and still not resolved.”
—Syris Valentine (@shapersyris.bsky.social), Science Writer
Citation: Valentine, S. (2025), Artisanal gold mining is destroying Amazonian peatlands,
Eos, 106, https://doi.org/10.1029/2025EO250195. Published on 20 May 2025.
Text © 2025. The authors.
CC BY-NC-ND 3.0Except where otherwise noted, images are subject to copyright. Any reuse without express permission from the copyright owner is prohibited.
