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July 2019, ScientificAmerican.com 45

the company’s concession. There were few

details yet and no hard benchmarks, but if

Rio Tinto followed through, the stance had

the potential to reverberate throughout

the industry, forcing mining companies to

compete for permits on the basis of their

environmental programs.

As part of this conservation initiative, Rio Tinto had created

what the company called a biodiversity committee made up of

researchers and nonprofit managers who could help its local sub-

sidiary, QIT Madagascar Minerals (QMM), plan and carry out envi-

ronmental work on the margins of what promised to be an enor-

mous mine. Madagascar’s government would receive a 20  per cent

stake in QMM—an investment that could generate hundreds of

millions of dollars in new revenue for the country over time. For

the scientists in the group, joining the committee represented a

leap of faith. Their input could prevent the worst and harness Rio

Tinto’s investment for environmental good. But it also meant

they would share the blame for anything that went wrong.

It didn’t take long. Within a few years of the committee’s in -

ception, its members repeatedly raised concerns that QMM was

not on track to meet its biodiversity goals. When ilmenite prices

slumped during the Great Recession, Rio Tinto’s priorities shift-

ed, and by 2016, the company reneged on its grand conservation

promise. Instead it adopted the vague goal of avoiding making

things too much worse. Today mining near Mandena is poised

to extinguish this biodiversity hotspot. For the people who live

there and dozens of endemic species such as the ring-wearing

tree frog, destiny now turns on the outcome of this long-run-

ning experiment, a test case for industry’s role in conservation

and the role conservationists can play in the mining industry.

In its natural state, ilmenite accumulates in the

deep sediments deposited by rivers and streams that changed

course long ago, forming a black sand so heavy it separates from

lighter minerals at the surface. To extract the mineral, miners

begin by using backhoes and chain saws to remove every scrap

of vegetation from each mining tract and
pile it into gargantuan mounds of com-
post. Earth-moving machines dig a trench
several stories deep and longer than a
football field, which is then filled with wa-
ter diverted from a nearby river. A dredge
stirs up sand from a depth of up to 18 me-
ters and pumps it onto a barge through an oversized straw,
where gravity separates some of the ilmenite ore from sand,
topsoil and lighter materials. Great “black snakes”—temporary
pipelines—crisscross the expanse, conveying the mineral-rich
slurry to a gleaming green processing plant near the water.
Electrostatic separation is used to extract still more ilmenite be-
fore the demineralized sand and soil are spread back out over
the landscape.
Rio Tinto discovered ilmenite near Tolagnaro in 1986. At the
time, the forests in the region were already heavily fragmented
and degraded by human activity. But the company’s prospecting
soon brought new roads to the area and an influx of people look-
ing for work, hastening the deforestation underway for charcoal
production and new farmland to supply the growing city.
Rio Tinto determined that the region around Tolagnaro con-
tained some 70  million metric tons of ilmenite—enough to sup-
ply about 10 percent of the global market for a decade or more—
and began to make a plan for extracting it. The company set its
sights on three mineral-rich areas along the coast encompass-
ing a total of approximately 6,000 hectares. Mining would start
at the 2,000-hectare site in Mandena and eventually expand
north to Sainte Luce and to Petriky farther south. The extrac-
tion would continue for the life of the mine—about 60 years
from the date of first production, according to the company’s
projections. Rio Tinto estimated that in the end the project
would result in the loss of 1,665 hectares, or 3.5 percent, of Mad-
agascar’s remaining littoral forest.
While Rio Tinto explored the area to gauge the full extent of
the ilmenite deposits, it initiated environmental studies. As
part of this effort, the company funded one of the first botanical
MARTELET CHRISTIAN inventories of forests along Madagascar’s eastern coast—Rio

Getty Images

SUN RISES over Tolagnaro

(Fort Dauphin), Madagascar.

Some 70 million metric tons of

ilmenite lie under the littoral

forest in this region.