Mining on the ocean floor could do irreversible damage to deep-sea ecosystems, not just at mining sites, but also across much larger areas, according to a new study of researchers from the University of Exeter and Greenpeace.
The study, published in the journal Frontiers in Marine Science, 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.”
As explained, rising demand for minerals and metals, including for use in new technology, has sparked renewed interest in seabed mining. 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 in early 2019.
The 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.
In addition, the paper notes 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.”
