by Mrinalini Erkenswick Watsa
August 04, 2015
from Mongabay Website


In the Peruvian Amazon,
a global craving for gold has changed life for local communities.

Gold mining is intensifying in southern Peru.

Researchers mapped mining-related deforestation
along a major river and in a protected reserve.

Gold mining often releases mercury into the environment,
which can be very harmful
for human and ecosystem health.


In the heart of the Peruvian Amazon, a global craving for precious metals has changed life for local communities.

As prices remain relatively high and it retains its reputation as a safe investment, the true costs of gold extraction ripple through the rainforests of Peru, affecting everything from fish to birds of prey, and even local human residents.

Along the way, trees continue to be felled to make way for mining rigs and makeshift homes that ultimately feed the world's appetite for the elemental metal.

More than 30,000 artisanal gold miners are estimated to be active in just the Madre de Dios Department of Peru - which is Spanish for "Mother of God."

In March of this year, the Monitoring of the Andean Amazon Project (MAAP) revealed that 1,700 hectares of gold mining-related deforestation occurred in the La Pampa region of the Madre de Dios Department of Peru.

Two months later in May, further evidence shows another 850 hectares of deforestation caused by gold mining in the Upper Malinowski River, a little west of La Pampa.

These figures were calculated by MAAP's unique approach to monitoring deforestation - an analysis of satellite imagery with a specialized software program called CLASLite developed by the Carnegie Institute for Science.

By comparing satellite imagery of the same location taken at different periods in time, the MAAP team, consisting of members of the Amazon Conservation Association, is able to carefully calculate actual deforestation levels, without ever needing to set foot in the area itself.


Expanding deforestation
from illegal gold mining along the Upper Malinowski River.
Key data sources: MINAM, SERNANP, ACCA, USGS, IBC, Hansen/UMD/Google/USGS/NASA.

Satellite image time-series (2013 - 2015)
of deforestation along the Upper Malinowski.
Note that all four panels in Image 5d show the same location.
Key data sources: USGS, SPOT 7.

Global Forest Watch data confirms the region

has lost primary tree cover since 2000.

The inset box shows the area of deforestation along the Upper Malinowski River,

likely caused by gold mining.

Terra-i data collected by satellites indicate

11 deforestation alerts have occurred there since 2009.

The most recent analyses reveal that deforestation is occurring in an area that is both outside the legally recognized mining corridor and inside the buffer zone of the Tambopata National Reserve.

"The Permissible Mining Zone was established in 2010 and indicates the zone that the Peruvian Government has delimited as potentially legal for small-scale and artisanal mining activities, but only if miners successfully complete a multi-step formalization process for each project," report Matt Finer and Sydney Novoa, lead MAAP researchers.

In another part of the Madre de Dios Department, MAAP revealed that deforestation in the mining zone known as Huepetuhe/Delta-1 is now entering the Amarakaeri Communal Reserve, which is co-managed by indigenous communities and Peru's National Protected Areas Service.

"Our analysis shows that gold mining deforestation, expanding from Huepetuhe/Delta-1, entered the southeast corner of the reserve in 2013 and expanded in 2014 and 2015," report Finer and Novoa.

Even more deforestation can be observed spreading within the reserve's southeastern buffer zone.

The patterns of deforestation they highlight in satellite images have been definitively identified as caused by gold mining, with other potential causes such as agriculture ruled out.

Gold Mining in Peru

Mining in the Madre de Dios has transformed the area, with riverbanks displaying evidence of mining in the hundreds of mounds of gravel that are the primary remnants of river silt washed clean for gold.

Aerial views leave a stronger impression - 2013 evaluations show that the mining extent in the region increased 400 percent from 2000 to 2012.

"According to a pair of technical reports by the Amazon Conservation Association (ACA) and Conservaciόn Amazόnica (ACCA), 2,500 hectares has been deforested in the Tambopata National Reserve buffer zone due to illegal mining in the past two years," states the ACA's Mining News Watch in June 2015, a regular compendium of gold mining related news and data.

Deforestation is not the only negative side effect of mining in the area.

Gold is often extracted using mercury, with which it forms an amalgam, making it easier to separate from sediment or ore. But mercury is highly dangerous when released into the environment, both via aerial and water-borne dispersal.


In sufficiently high doses it can cause birth defects and neurological disorders such as Minamata Disease.

However, that is exactly what must happen to retrieve pure gold - the mercury is burned off to leave only the gold, causing unbounded mercury to be released into the water and air.

Recent calculations by the Ministry of the environment revealed that 40.5 metric tons of mercury enters the Madre de Dios River annually, which amounts to 5.6 percent of the world's mercury pollution produced by artisanal mining.

This mercury then enters a range of organisms that live in the river, eventually accumulating in high levels in animals that occupy the top rungs of the food chain.

A study in 2013 in the Journal of Environmental Protection found that several fish species surveyed in the Tambopata region had methylmercury levels higher than the U.S. Environmental Protection Agency fish tissue criterion for human consumption above which consumption poses a danger to human health, with some samples showing more than twice the criterion.


An enhanced view of the deforestation within the southeast section
of Amarakaeri Communal Reserve and its surrounding buffer zone.
Key data sources: MINAM, SERNANP, ACCA, Hansen/UMD/Google/USGS/NASA, USGS.

Satellite (Landsat 8) image time-series (2013 - 2015)
of deforestation within the southeast section of the Amarakaeri Communal Reserve.
Note that all four panels show the same location over time.
Key data sources: USGS, SERNANP.

Terra-i data from Global Forest Watch show many alerts

have occurred in the Amarakaeri buffer zone since 2004,

correlating to a large swath of primary forest

that has been degraded since 2000.

According to the UN Environment Program's Global Mercury Assessment of 2013, the world's second largest contributor to mercury pollution is artisanal and small-scale gold mining (ASGM), conducted by small groups or families without official government permits, who work a portion of the year and generally do not officially declare such earnings for tax purposes.

Attempts by the Peruvian government to regulate such mining activities have ranged from highly bureaucratic only-on-paper resolutions to active military efforts to bomb barges on the Madre de Dios.


Recently, however, a formalization process was finally created to allow people to acquire mining permits legally. According to Mining News Watch, only 16 permits have been issued to date, which affect only 1 percent of the 58,835 miners that began the application process in Puno.


No such permits had been legalized as of June 10, 2015 in Madre de Dios.

Madre de Dios Regional President Luis Otsuka, in a meeting, stated categorically that he would continue to sell gold on the black market. He drew attention to the glacial pace of the legalization process, demanding a speedier way to transform undocumented mines into legal, tax-paying entities.


Río Huaypetue gold mine in Peru.
Photo by Rhett A. Butler

"According to the Peruvian Financial Intelligence Unit (UIF), between January and December 2014, illegal mining generated $2,765 million, surpassing illegal drug trafficking, which generated $78 million.


The Office for National Electoral Processes reports that money from both mining and drug trafficking is making its way into the electoral campaigns of political organizations," states Mining News Watch.

Meanwhile, the health of local miners continues to suffer.


Assessments conducted in 2010 of mercury levels of blood and urine from residents of Huaypetue, an artisanal gold mining town, revealed that people who heated gold-mercury amalgams had total urine mercury concentrations nearly twice as high as those who did not.


In addition, community members who consumed fish had methylmercury concentrations that were 60 percent higher than nonfish consumers.

Matt Finer told in an interview that MAAP monitors 30 different areas in Peru, releasing a new set of images on unmonitored deforestation once a week.


Their goal is to get the facts verified and published quickly, so that the relevant authorities may act upon them, thus drawing attention to deforestation, in real-time, in areas that cannot be easily monitored from the ground.


  • Finer M, Novoa S (2015) - Gold Mining Deforestation Intensifies along Upper Malinowski (Madre de Dios, Peru) - MAAP: Image #5.

  • Finer M, Novoa S (2015) - Gold Mining Deforestation Enters Amarakaeri Communal Reserve (Madre de Dios, Peru) - MAAP: Image #6.

  • Fraser, B. (2009) - Peruvian gold rush threatens health and the environment - Environmental science & technology, 43(19), 7162-7164.

  • DeRycke E, Finer M (2015). Peru Mining News Watch Report #16 - Amazon Conservation Association.

  • Roach, K. A., Jacobsen, N. F., Fiorello, C. V., Stronza, A., & Winemiller, K. O. (2013) - Gold mining and mercury bioaccumulation in a floodplain lake and main channel of the Tambopata River, Peru.

  • Yard, E. E., Horton, J., Schier, J. G., Caldwell, K., Sanchez, C., Lewis, L., & Gastaňaga, C. (2012) - Mercury exposure among artisanal gold miners in Madre de Dios, Peru: a cross-sectional study - Journal of Medical Toxicology, 8(4), 441-448.