The scientists restoring a gold-mining disaster in the Peruvian Amazon – by Jeff Tollefson ( – February 4, 2020)

Months after the military expelled thousands of illegal miners from La Pampa, researchers gained access to a sandy wasteland.

“Holy shit!” Miles Silman gasped as his motorized rickshaw rattled out of the forest and onto a desolate beach. All traces of the trees, vines and swamps that once covered this patch of the Amazon had vanished. In their place were sun-baked dunes and polluted ponds created by illegal gold-mining. Silman, a conservation biologist at Wake Forest University in Winston-Salem, North Carolina, was there to document the carnage.

La Pampa was once the largest and most dangerous gold-mining zone in the Peruvian Amazon, so riddled with gangsters that scientists dared not enter. For nearly a decade, they could only watch by satellite as gold hunters mowed down some of the most biodiverse rainforest on the planet. That ended in February 2019, when the government declared martial law and expelled an estimated 5,000 miners.

Now, La Pampa is deserted and under military guard. When Silman and his colleagues surveyed the area for the first time in late June, they found a barren, eerily quiet landscape polluted with mercury, a toxic by-product of mining. The data that the researchers collect on this inadvertent experiment could help to determine the extent to which restoration is possible — or document the evolution of an entirely new, and human-made, ecosystem.

Silman and his colleagues at the Center for Amazonian Science and Innovation (CINCIA), a non-profit research institute in Puerto Maldonado, Peru, has spent the past several months mapping the area with drones and surveying the remaining plants and animals. The team has been studying dozens of tree species to see which ones can survive among the dunes and along the shores of ponds.

CINCIA scientists have also tested the air, water and soil for mercury contamination. Another team, from Duke University in Durham, North Carolina, has collected data there to help unravel how mercury — which can harm children’s brain development — moves from polluted water or soil and up the food chain.

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