By Rhett Butler of mongabay.com
French Guiana's Amazon is some of the least spoiled
The biological riches of the small Amazon country of French Guiana are coming under threat from high gold prices.
The French government, which has jurisdiction for the country, recently moved to block a controversial project from the Toronto-based Iamgold company to mine deposits near the highly sensitive Kaw area.
But local scientists say the rainforests of France's biologically-rich overseas department are still at risk from illegal gold miners, known as garimpeiros.
"The open pit mine would have threatened key forest habitat of Kaw," said Dr. Pierre-Michel Forget, a biologist from the Museum National d'Histoire Naturelle in Brunoy, France, who has worked in the region for more than 20 years.
"But we still have to think about the garimpeiros from Brazil."
France's President Sarkozy has visited the country to discuss the Amazon
Since the 1980s, French Guiana's remote and poorly-monitored borders have made it an attractive mining site for more than 10,000 informal miners from Brazil.
Lured by high gold prices and wages paid in euros, the garimpeiros use both rudimentary and mechanised methods to expose and extract gold from gravel deposits. In the process, toxic compounds including mercury and heavy metals are released, contaminating local waterways.
Mercury is particularly problematic. Deposited in rivers, mercury can be methylated into organic forms where it then enters the food chain, accumulating in top level predators like otters, birds of prey, and humans, where it can cause neurological disorders and birth defects.
Samples taken in villages near mining areas in French Guiana have found mercury levels six times higher than concentrations allowed by the European Authority.
The illicit mining has other effects as well. While official figures show only minimal deforestation in French Guiana, some miners' impacts - including hunting of wildlife and clearing of understory vegetation, which leaves leaves tropical forests more vulnerable to fire - can be virtually undetectable.
The French government has responded by sending more police to patrol mining areas.
After some early difficulties working in an environment so different from the urban and suburban areas of France, the gendarmerie today use remote sensing and other tools to find camps and send garimpeiros back to Brazil.
But Dr Forget stressed that mining will continue to be an issue for French Guiana's forests.
"While there are some areas of extremely high biodiversity or sensitivity that should definitely be off-limits to any form of mining or development... there are other areas in French Guiana where the forest can be mined in a responsible manner," he explained.
"There will always be ecological concerns, but the question is rather what we can accept today in light of French Guiana's need for development and the high demand from China and India for gold, bauxite, and other resources."