Ambitious research aims to limit environmental damage on the sea floor – but some scientists fear mining this pitch black world will do more harm than good
Carol J Clouse | The Guardian | 28 June 2017
Each of the three mining machines outweighs the 200-ton blue whale – the largest animal the world has ever known – and they look fearsome, especially the bulk-cutter designed to grind up the ocean floor with its enormous roller, covered in spikes.
If all goes as planned, come 2019 these giant remote-controlled robots will steamroll across the bottom of the Bismarck Sea off the coast of Papua New Guinea, chewing it up in pursuit of rich copper and gold reserves for a Canadian company called Nautilus Minerals. Nautilus chief executive Michael Johnston is anxious to demonstrate something besides making handsome profits. He also wants to show that his company has designed the mining expedition to have a small environmental footprint, especially when compared to the land-based counterpart.
“People have a view of mining, and they think we’re going to transport that view into the ocean, and it’s going to be ugly,” says Johnston, a soft-spoken New Zealand native and a 30-year veteran of mining.
“It’s important to all of us, especially those of us who’ve worked in mining for a number of years, to show people that you can do it better. I think a lot of people will be surprised,” says Johnson, 54, who joined Nautilus in 2006.
Johnston will have a lot to prove. The project, Solwara-1, will be the first ever attempt to extract minerals from the deep sea, and with the world watching closely.
Deep sea mining presents an ethical conundrum and an opportunity to avoid the costly environmental and social mistakes of land-based mining. That has prompted a group of policymakers, businesses and academic researchers to design rules that they hope will minimize environmental harm. They have proposed ideas that range from setting aside no-mining zones within a region rich in minerals to using technology that will reduce the extent of sediment plumes during dredging.
“We have the opportunity from the very beginning to understand the science, to understand the impact and to understand how to ameliorate the impacts,” says Dr James Hein, a senior scientist with the US Geological Survey. “This will really be the first time we can approach it from step one.”
But whether any of those ideas will work as designed to reduce environmental impact won’t be known until the machines are put to work. Some of Nautilus’s proposals, such as relocating some of the wildlife temporary to another location during mineral extraction – and recolonizing the spot afterward – attract strong skepticism.
“Nautilus’s claims that they can simply relocate parts of the site’s ecosystem elsewhere don’t stand up to scientific scrutiny, and the effectiveness of any measures to reduce other impacts will be difficult, if not impossible, to verify independently,” says Dr David Santillo, senior scientist at Greenpeace Research Laboratories at the University of Exeter in the UK.
Earth’s last mining frontier
The deep ocean plays a critical role in the Earth’s biosphere – it regulates global temperatures, stores carbon and provides habitat for a huge array of creatures. Scientists and environmental advocates fear that mining this pitch black, frigid world will not only kill any marine life that gets in the way of the machines but could potentially devastate far wider areas by stirring up plumes of sediment and introducing chemical, noise and light pollution.
Their worries underpin a sentiment that deep-sea mining appears inevitable. Demand for minerals to make virtually everything we use, including the phones and computers that run our lives, will only increase. Even technology that promises to cut our oil addiction and reduce emissions requires a reliable supply of raw materials, from tellurium for solar panels to lithium for electric vehicle batteries.
The vast treasure of untouched resources on the ocean floor – copper, zinc, cobalt, manganese, titanium and other minerals – has tantalized mining companies around the globe.
The Clarion-Clipperton Zone (CCZ) is a particularly a coveted mining area that’s roughly the size of the continental US and lies between Mexico and Hawaii. It contains potato-sized nodules of manganese, cobalt, nickel, copper and molybdenum worth roughly $25.2tn, according to Hein’s calculations. Not all of this amount would be economically recoverable, Hein says, but even 30% would equal $7.56tn.
Moreover, these minerals exist at much higher grades than on land, where supplies that are easily accessible have mostly been depleted and mining companies are blowing the tops off mountains, cutting down wider expanses of forests and digging ever-bigger holes to extract from harder-to-reach deposits.
Mining copper in the Andes, which produces about 40% of the world’s supply, would require the removal of 50 tons of barren rock to get to a 20 million ton ore deposit with 0.5% copper in it, Hein says. In a marine environment, you can find a 7% copper deposit sitting right on the seafloor.
Of the 28 exploratory contracts signed with the International Seabed Authority, which regulates undersea mining in international waters, 16 are for mining in the CCZ. The US hasn’t ratified the treaty and joined the ISA. US aerospace and defense firm Lockheed Martin has obtained two exploratory contracts through its British subsidiary UK Seabed Resources.
Deep-sea mining is an expensive undertaking. Nautilus has encountered delays for its roughly $480m project and still needs to raise $150m to $250m to move ahead.
Around the world, extensive work is now going into mapping ocean floor ecosystems and researching ways to mitigate the environmental impact of deep-sea mining. In the US, the National Oceanic and Atmospheric Administration has done exploratory and mapping work off the coast of Hawaii, along with projects by university researchers.
The European Union has contributed millions of dollars to organizations such as MIDAS (Managing Impacts of Deep-Sea Resource Exploitation), and Blue Mining, an international consortium of 19 industry and research organizations.
A UK-funded expedition conducted the first ever controlled deep-sea sediment plume experiment in the Atlantic last year, about 300 miles from the Canary Islands. Sediment plumes are big dust clouds kicked up by mineral extraction, and scientists worry that the plumes could travel great distances, choking sea life along the way.
“There’s a lot more research to be done on sediment plumes,” says Dr Bramley Murton, who led the expedition and heads the marine mineral research at the UK’s National Oceanography Center. “But we got some data and, at the moment, the initial indication is that we can’t see the plume from a kilometer, or roughly 0.6 miles, away.”
That’s an encouraging result, because scientists previously suspected that sediment plumes would travel much further.
Another way to minimize impact is to aside protected areas within mining zones. Back in 2013, a team of scientists led by Dr Craig Smith, a professor of oceanography in University of Hawaii’s Mānoa’s School of Ocean and Earth Sciences and Technology, recommended the ISA to designate roughly a quarter of the CCZ as a protected area. The ISA accepted the team’s recommendations provisionally but will need to decide whether to include them in the final rules, which could take three to five years to finalize.
Improving the precision of mining robots will also help to reduce environmental disturbances. Companies with the technology that could solve the problem include the Seattle-based BluHaptics, which has developed software that enables a robot to recalibrate its aim and movement to improve precision by learning from each trip it makes to the seabed.
“We use machine learning software to identify and track objects in real time, with high resolution situational awareness, so it can see through sediment or oil spills,” says Don Pickering, BluHaptics’ CEO.
What will Nautilus do?
At the Solwara-1 site, 25km off the Papua New Guinea coast, Nautilus plans to launch its project from a ship 230 meters long and 40 meters wide, with roughly 130 employees on it. The company will go after minerals born 1,000–3,000 meters deep in volcanically active zones, around vents that spurt super hot, acidic water containing metals dissolved from the earth’s crust. The active vents are populated by numerous species, including tubeworms, clams, snails, shrimp, crabs and many species that are not yet known.
The three Nautilus robots, designed by UK-based SMD, will be lowered into the water, break up the rocks and collect them to be piped back to the vessel.
The ore will then be transported by smaller boats to China and sold to the Tongling Nonferrous Metals Group Holding Co. The ship plans to remain at the first project site for roughly three years, bringing up 2.5 million metric tons of ore containing metals worth roughly $1.5bn, give or take shifts in commodity prices.
To address sediment plumes, SMD designed the robots to suck the plume into the slurry with the ore and pump it up into the vessel. “Our ultimate goal is to recover as much of the material as possible, not to blow it away,” Johnston says.
Using a steel riser and pump system designed by GE Oil & Gas, once the ore is dropped into the vessel, the icy water will be pumped back down to the sea floor so it doesn’t mix with the warmer surface water and potentially cause algae blooms and other environmental disturbances. To minimize the use of bright light, which could disrupt marine life in the pitch black world, Nautilus will use sonar and digital cameras to create 3D maps to guide its extraction with the remotely operated robots.
“These populations grow fast and they reproduce a lot, so in some sense one can argue that they might recover quickly. But the environmental issue is that these habitats are relatively rare on the sea floor, and they’re different from one site to the next because the animals have adapted to the fluid chemistries,” says Dr Cindy Lee Van Dover, director of the Duke University Marine Laboratory in North Carolina and a member of the Deep-Ocean Stewardship Initiative, an international group of scientists, lawyers and advocates that makes environmental recommendations to the ISA.
“We aren’t talking about stopping mining, just thinking about how to do it well. We can map these environments to show where the highest density of animals is and avoid those high-density places. That’s a very rational approach,” says Van Dover. “I’m reasonably optimistic that we can come up with progressive environmental regulations.”