Seabed mining could
destroy ecosystems
University of Exeter
Mining on the ocean
floor could do irreversible damage to deep-sea ecosystems, says a new study of
seabed mining proposals around the world.
The deep sea (depths
below 200m) covers about half of the Earth's surface and is home to a vast
range of species.
Little is known about
these environments, and researchers from the University of Exeter and
Greenpeace say mining could have "long-lasting and unforeseen
consequences"- not just at mining sites but also across much larger areas.
The study is the first
to give a global overview of all current plans to mine the seabed, in both
national and international waters, and looks at the potential impacts including
physical destruction of seabed habitats, creation of large underwater plumes of
sediment and the effects of chemical, noise and light pollution arising from
mining operations.
"Our knowledge of
these ecosystems is still limited, but we know they're very sensitive,"
said Dr David Santillo, a marine biologist and senior Greenpeace scientist
based at the University of Exeter. "Recovery from man-made disturbance
could take decades, centuries or even millennia, if these ecosystems recover at
all."
Despite the term
"mining," much seabed mining would involve extraction of minerals
over very wide areas of the sea floor rather than digging down to any great
depth, potentially leaving a vast 'footprint' on the deep-sea habitats in which
these mineral deposits occur.
Rising demand for
minerals and metals, including for use in new technology, has sparked renewed
interest in seabed mining.
Some operations are already
taking place, generally at relatively shallow depths near national coastlines.
The first commercial
enterprise in deeper waters, expected to target mineral-rich sulphides at
depths of 1.5-2km off Papua New Guinea, is scheduled to begin early in 2019.
Speaking about these
plans last year, Sir David Attenborough said it was "tragic that humanity
should just plough on with no regard for the consequences."
The Exeter and
Greenpeace research team say there are "many questions and
uncertainties" around seabed mining, including legal issues and the
difficulties of predicting the scale and extent of impacts in advance, and of
monitoring and regulating mining activity once it takes place in the deep sea.
The paper says that
alternatives to seabed mining have already been proposed, including
substituting metals in short supply for more abundant minerals with similar
properties, as well as more effective collection and recycling of components
from disused products and wastes.
However, Dr Santillo
said demand for seabed mining would also diminish if humanity could cut
overproduction and overconsumption of consumer goods.
"Rather than
using human ingenuity to invent more and more consumer products that we don't
actually need, we could deploy it instead to build goods that last longer, are
easier to repair and make better use of the limited natural resources we
have," he said.
"With the right
approaches, we can avoid the need for seabed mining altogether and stop the
'race to the bottom'.
"As governments
prepare to set the rules and the first companies gear up to mine, now is the
time to ask whether we just have to accept seabed mining, or should instead
decide that the potential damage is just so great that we really need to find
less destructive alternatives."