BOGOTA (Thomson Reuters Foundation) - A rise in small-scale illegal gold mining is destroying swathes of the Amazon rainforest, according to research released on Monday that maps the scale of the damage for the first time.

Researchers used satellite imagery and government data to identify at least 2,312 illegal mining sites across six countries in South America - Brazil, Bolivia, Colombia, Peru, Ecuador and Venezuela.

The maps show the spread and scale of illegal mining and were produced by the Amazon Socio-environmental, Geo-referenced Information Project (RAISG), which brings together a network of nonprofit environmental groups in the Amazon.

“The scope of illegal mining in the Amazon, especially in indigenous territories and protected natural areas, has grown exponentially in recent years, with the rise in the price of gold,” said Beto Ricardo, head of the RAISG.

Soaring prices in the decade to 2010 sparked a gold rush and hundreds of thousands of illegal miners poured into the Amazon rainforest hoping to strike it rich.

The mercury they use to separate gold from grit is poisoning the rivers, the report said. Mercury seeps into soil, rivers and the food chain and can cause serious health problems.

“Illegal mining can kill us,” Agustin Ojeda, an indigenous leader of Venezuela’s Shirian indigenous people, is quoted as saying in the report.

“The mining wells allow for the reproduction of mosquitoes that bring diseases, such as malaria. The effect of mercury on water isn’t taken seriously either. It not only contaminates water but also the fish we eat.”

Environmentalists fear Brazil’s President-elect Jair Bolsonaro will open up more protected land for mining and other projects when he takes office on January 1, placing further pressure on the Amazon.

Right-wing Bolsonaro has said he plans to stop recognizing new native reservation lands, and he also favors a relaxation of environmental licensing processes for infrastructure projects and other businesses.

“The concern is enormous,” said Ricardo, who is also an anthropologist at Brazil’s Socioenvironmental Institute (ISA), one of the six groups that produced the report.

“The public narrative is to clear the area (of forests), weaken those institutions that monitor and control in favor of agribusiness and mining for the production and export of commodities, which will hasten the deterioration of the forest,” he told the Thomson Reuters Foundation.

Brazil is home to the world’s largest rainforest in the Amazon, whose preservation is seen by climate experts as critical to avoiding higher concentrations of carbon dioxide in the atmosphere that have been blamed for global warming.

In one of the worst hit areas, stretching between Brazil and Venezuela and home to the Yanomami indigenous people, the study showed there were 55 illegal mining sites in protected areas.

“Illegal mining is a serious threat to the Amazon rainforest and the indigenous peoples who call it home,” said Moira Birss, spokeswoman for Amazon Watch, a U.S.-based non-profit group.

“This report provides important new data and clearly demonstrates the scope of the problem, and as such is a call to action to regional governments and the companies that purchase the illegally-mined minerals to take bold, concrete action to stop the destruction.”