As our plane topped the Peruvian Andes, I looked out the window and caught my first view of the headwaters of the Amazon. The green canopy of the rain forest spread out in all directions. Yet on closer examination, I noticed the wilderness was marred by a checkerboard of cleared fields, scarred stream banks and rivers stained brown by polluted runoff.
Naive tourists that we were, my wife, Micaela, and I were starting a visit last month to the Madre de Dios region of southeastern Peru, near the border of Bolivia. Our destination was Tambopata National Reserve, a lush sanctuary that is considered one of the most biodiverse places on the planet. After landing, we traveled by boat up the Tambopata River, where we would spend the next three nights in rustic cabanas outfitted with mosquito nets and candles.
Our visit to Tambopata exceeded our wildest expectations. In just a few days, we saw rare monkeys, scores of parrots, macaws and other birds and had encounters with snakes, tarantulas, baby caimans, capybaras (the world's largest rodent) and many other creatures.
But we became quickly aware that this island of protected rain forest is under siege. Record-high gold prices have drawn thousands of destitute, would-be miners to Madre de Dios. In scenes reminiscent of California's Gold Rush, they are clearing forests, using hydraulic hoses to unearth ore from the exposed soil, and attempting to separate gold with globs of toxic mercury.
"These are basically poor farmers from the Andes who have come to the Madre de Dios," said Luis E. Fernandez, a visiting researcher at Stanford University who is part of a scientific team studying the impacts of Amazonian gold mining. "They are unaware of the risks of mercury, to themselves or the environment."
According to Fernandez, there are as many as 40,000 illegal miners in the area, operating with no permits and little government oversight. A black market has sprouted for both gold and mercury, he said, part of a wider illegal economy that has made Puerto Maldonado – the major town in the region – a volatile and often dangerous place.
When the miners bring their gold to town, they attempt to sell it at numerous small shops that have sprouted across Puerto Maldonado. To make sure they are paying for the exact weight, the shop owners heat up the gold to burn off the residual mercury (which is heavier than gold), wafting mercury vapors into surrounding neighborhoods.
Many locals say that the ultimate purchasers of gold are cocaine traffickers looking for ways to launder their drug money. Both the drug runners and miners have a mutual interest in keeping out government authorities, who have made sporadic attempts to crack down on illegal mining.
In March, an estimated 12,000 miners rioted, battling police and attempting to seize public buildings in Puerto Maldonado, a city and region of roughly 90,000 people. According to the Associated Press, three people were killed by gunfire and 38 were injured in the riots, sparked by government efforts to regulate the miners.
Two weeks ago, eight men with machine guns entered the airport in Puerto Maldonado and forced travelers and airport employees to lie on the ground.
They then stole 10 kilograms of gold from a passenger before firing into the air and making their escape. Two people were wounded in the assault, which occurred two days before my wife and I landed in Puerto Maldonado.
Widespread illegal mining
Micaela and I wear gold wedding bands on our fingers. But like a lot of people, we've never given much thought to where that gold originated, or where it is being currently mined.
With prices now topping $1,700 an ounce – more than six times the price on Sept. 10, 2001 – would-be miners are scouring every possible source. That includes seemingly tapped-out historic sites, such as the Sierra foothills in California. But more often it means remote mother lodes, such as those in Indonesia, Ghana, Borneo and the Amazon.
According to National Geographic, a quarter of the world's gold is illegally mined.
While visiting the Tambopata National Reserve, we had the good fortune of being led through the forest by a local guide, Jorge, a 26-year-old native of Puerto Maldonado. A sharp-eyed spotter of wildlife and native medicinal plants, Jorge said his home region has changed dramatically in his lifetime, in ways good and bad.
A new transcontinental highway slices through the town, and a new suspension bridge has replaced ferries across the vast Madre de Dios River. That new infrastructure has helped bring tourists to Puerto Maldonado, says Jorge, but it has brought outsiders, especially the miners, who are dramatically altering the ecosystem.
Rivers that once ran clear and tea-colored most of the year are now pervasively muddy, carrying a heavy load of sediment. "Basically, the miners blast out the riverbank and drop all the dirt into the river," said Fernandez. The result, he said, is a river that looks like flowing cappuccino, with the sediment blocking out light that many aquatic species need to survive.
But it's what you can't see in the river that most concerns the locals.
When I told Jorge I had experience writing about mercury contamination from California's old mine, he started plying me with questions.
"Stuart, do you think the mercury is getting into our fish, our animals?" he asked.
As it turns out, it is much worse than that.
Mercury's toxic effects
Since 2008, Fernandez and his colleagues at the Carnegie Institution's Department of Global Ecology have immersed themselves in a study of gold mining in the Madre de Dios. Much of the focus is on mercury – how it is used in mining (half of it lost to the environment) and what happens to it after being dumped into rivers and lakes by miners and burned off by gold merchants.
A highly toxic metal, mercury can be poisonous upon contact, and poses special problems when it breaks down in the environment, becoming methyl mercury and spreading up the food chain. Mercury exposure poses a special threat to young children and child-bearing women who eat contaminated fish. At high enough levels, it can be deadly or cause a child to have lifetime neurological problems.
So far, Fernandez and his team have examined mercury buildup in fish, tested air samples in Puerto Maldonado and obtained hair samples from 1,000 people to test for mercury. Results to date show that people in parts of Puerto Maldonado are exposed to mercury levels up to 20 times higher than the U.S. Environmental Protection Agency's standard for industrial exposure, he said.
Although final results may not be ready for a few more months, hair sample tests show an elevated level of mercury in local children and adults. If these results hold, "A lot of these children could have lifetime problems because of the mercury levels they are being exposed to," said Fernandez, speaking to me via Skype from Peru's capital, Lima.
Gold mining also threatens the once-abundant wildlife of Madre de Dios. Using aerial mapping, the Carnegie Institution has identified mining as the region's single largest cause of deforestation – uprooting more than 127 square miles of the region since 1999. And even in intact forests, numerous sensitive species – ranging from eagles to caimans to jaguars – are being exposed to mercury from fish and other creatures they eat from the rivers.
During our stay in the Tambopata reserve, we hiked for two hours through the jungle to reach Cocococha, a pristine oxbow lake formed by an old meander in the nearby river. After paddling around the lake in a canoe for more than an hour, we finally were rewarded with the prize of our expedition – a sighting of giant river otters.
A top predator in the Amazon, giant otters grow to more than 5 feet long and have teeth and jaws strong enough to fend off caimans and other carnivores. Hunted for decades for their pelts, they are listed as globally endangered, with most remaining populations residing in protected reserves of the Amazon, such as Tambopata.
Eight otters popped from the water as we paddled near, with some baring their teeth to ward us off. No one knows yet if these creatures are threatened by mercury contamination. But because they are heavy fish eaters – and because some fish migrate between oxbow lakes and rivers – researchers are concerned that otters could become poisoned by mercury, harming their reproduction.
Given the country's history, this modern-day gold rush is especially tragic for Peru. Before the Spanish conquistadors invaded in the early 1500s, the Incas and other native Peruvians valued gold for its ceremonial beauty, but they did not trade it as a commodity, as Wall Street and gold merchants do today. The conquistadors changed all that, plundering Inca temples, melting down exquisite artworks and shipping much of the booty back to Spain.
According to Fernandez, the Peruvian government is attempting to regulate and formalize the illegal mining in Madre de Dios, partly to recover tax revenue that is lost to the black market. Yet it is unlikely, with gold prices as high as they are, that South American governments can fully prevent the plunder of the Amazon. The run on gold is a direct result of paranoia – distorted fear that the world's finances could collapse, leaving gold as the only secure investment. That paranoia will only ease if Congress, Wall Street, the European Union and other financial powerhouses get their acts together.
Until then, the Wild West for gold will flourish, with places like the Amazon becoming collateral damage.