If tens of thousands of miners turned up in the middle of a protected rainforest to mine for sapphires, you might expect that to cause lots of deforestation and harm local wildlife.
Mining has a very bad reputation. It is often assumed to be one of the worse land uses - destroying and polluting the environment and creating barren, moon-like landscapes. Where mining occurs in areas of high biodiversity, it is considered a serious threat.
But in the eastern rainforests of Madagascar, over 10,000 people mining for sapphires didn't cause more damage to the forest than farmers clearing land for agriculture, which remains the most important driver of deforestation in this area.
My recent research focuses on quantifying the effects of sapphire mining on the forests of Madagascar. My discoveries challenge some of the preconceptions about the impacts of small-scale mining. I show that, despite being attention-grabbing, some forms of mining can be surprisingly low-impact and less damaging than other land uses.
In October 2016, a valuable deposit of sapphires was discovered by people searching for gold within the protected rainforests of the Ankeniheny-Zahamena corridor in eastern Madagascar. These rainforests are really important for biodiversity as they are home to many unique species at risk of extinction, including lemurs such as the indri and black and white ruffed lemur. Word of the sapphire discovery quickly spread. Within weeks tens of thousands of people from across the island were illegally mining in the Bemainty valley deep within the forest.
Miners used shovels to dig pits between 1m and 3m deep in the valley floor to extract river sediments. They used handmade sieves and water from the stream to sieve the sediment and search for gems. The work was hard, living conditions in the hastily constructed settlements were poor, and the rewards were uncertain.
Unlucky miners left the site poorer than they arrived. Some struck it rich, while others made enough money to survive and perhaps save a little extra to invest in education, land or businesses. This type of mining, termed artisanal and small-scale mining, is not unique to Madagascar. It is widespread, supporting an estimated 40 million people around the world.
The mining rush at Bemainty attracted international media attention due to fears over its environmental impacts, with reports that it was causing substantial deforestation and threatening endangered lemur populations. This caused substantial concern amongst conservationists.
My research aimed to evaluate the deforestation claims. To properly assess the impact of something, an essential step is to estimate what would have happened without it: the counterfactual. To roughly calculate how much deforestation would have happened at Bemainty without mining, my colleagues and I used the average area of deforestation within a set of control forest areas, chosen to be as similar as possible to Bemainty but crucially, without mining. We then compared deforestation at Bemainty to this counterfactual.
We found that mining at Bemainty did not cause more deforestation than we estimate would have happened anyway from other causes. In this area, the biggest driver of deforestation is shifting agriculture, where people cut and burn patches of forest on slopes to grow rice for a few years in a rotational cycle. We showed that more than 10,000 people mining in the area did not cause more deforestation than several hundred people clearing forest for farming. The impacts of the artisanal gem rush need to be considered within this broader context.
Limited negative effects of mining on deforestation at Bemainty could be for several reasons. First, the sapphires were found within river sediments, confining mining to the valley floor.
Second, much of this area had been cleared for farming decades before when the first settlers arrived. Third, the miners did not use heavy machinery, and sapphire mining does not use toxic chemicals (like the mercury that's used in gold mining).
The variability of small-scale mining
More broadly, these results highlight that the environmental impacts of artisanal mining are very variable. They depend on the scale, methods, machinery and chemicals used, and the environmental impact of alternative land uses that people might be doing otherwise, like farming or cutting down trees to make charcoal. Although in some places artisanal and small-scale mining is causing major environmental problems, where mining is small-scale and doesn't use heavy machinery or chemicals, environmental effects may be similarly limited.
However, in many countries this variability is not considered in policies towards artisanal mining. Policies tend to focus on criminalising or otherwise stopping artisanal mining, but often have little effect. I believe that these one-size-fits-all policies are strongly influenced by negative preconceptions about mining and the worst case scenarios, and not necessarily specific evidence, which is lacking for many countries.
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Treating all mining as the same needs to stop. Artisanal mining provides income for millions of poor people around the world who, despite the challenges, decide it is their best - and perhaps only - option. Given its importance, policymakers need to rethink their preconceptions. Where mining has a low environmental impact, more open-minded, flexible policies are needed to regulate it in a way which balances the needs of poor communities with biodiversity conservation.
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Katie Devenish, Postdoctoral Researcher in Sustainable Land Use, University of Manchester
