The next potential horrorshow for our oceans

I started monitoring the internet for articles about deep-sea mining in about 2012, when an article in The Guardian reported that a commercial firm was going to begin mining the seafloor near Papua New Guinea for precious metals.

A "new frontier" in mining is set to be opened up by the underwater extraction of resources from the seabed off the coast of Papua New Guinea, despite vehement objections from environmentalists and local activists.

Canadian firm Nautilus Minerals has been granted a 20-year licence by the PNG government to commence the Solwara 1 project, the world's first commercial deep sea mining operation.

Nautilus will mine an area 1.6km beneath the Bismarck Sea, 50km off the coast of the PNG island of New Britain. The ore extracted contains high-grade copper and gold.

The mining company dismissed fears of environmental damage:

"The material is very high grade so you have to mine less in order to get the same amount of metal," said Chris Yeats, a geologist at CSIRO, the Australian government's scientific arm. "At those depths there are bacteria, but there's a cut off at around 1,000m where most fish are, so it should have little impact."

"Unlike a terrestrial mine, you don't have to build infrastructure such as roads and you don't displace people. You chop off one of these venting chimneys and another one will grow back, so it's a little like the mining equivalent of cutting grass."

In 2016 a UK company joined the Canadian one, although that one was going to focus on extinct vents:

Prime minister David Cameron has said such exploits could be worth £40bn to the UK alone and in March, a UK company won a second licence from the International Seabed Authority to prospect in 75,000 sq km of the Pacific...

They will use robot submarines to be the first to drill into extinct vent deposits, using a specially hardened drill to probe 55 metres below the sea bed... A key question is how much the seawater has rusted away the metals deposited by the hot springs that stopped flowing up to 50,000 years ago.

The deposits can be extremely rich in valuable metals, including gold, cobalt, zinc, tellurium and so-called “rare earths”, which are used in many electrical technologies, including smartphones, wind turbines, solar panels and electric cars and in high-strength, lightweight alloys used in aircraft, for example...

“There is absolutely no suggestion or enthusiasm from either scientists, or mining companies as far as I know, to go anywhere near the active hydrothermal systems,” said Murton. “They are extraordinarily rich areas of unique species and ecosystems and we wouldn’t do anything to disturb those.” 

The situation was informally summed up by a geology student: 

This is going to happen, people. The natural resources industry is becoming desperate to find new mineral deposits, as the replacement rate of new discoveries is lagging consumption by a significant margin. Never before has the industry been so desperate to find new projects, which is why multinational miners are more willing than ever to work in the worst of the third-world nations or in formerly frozen terrains that are only now being exposed by global warming...

Seafloor mining is NOT going to be particularly environmentally destructive. Nearly all of the black smokers in question that are going to be mined are geologically dead, having moved too far away from undersea volcanic activity. These deposits are MASSIVE. The potential profitability is astounding. Some of these deposits have been noted to contain nearly 20% copper in megaton quantities, versus the .4% that is typical of modern open-pit porphyry deposits, the immense pits in the earth that you've all seen pictures of.

Where you get to mining active black smokers, though, the situation gets interesting. In these cases, the smokers can physically grow by 3 feet or more per day, with god only knows what kinds of growth on the sulfide fields surrounding the smokers. Experts have been speculating that you could attach a pipe to the end of a black smoker and from there dry out and process the supercritical, black smoker water, which can be 50 weight percent or higher enriched in potentially economic metals. Here, we are for all intents and purposes talking about a renewable source of metals - an astounding proposition.

Success in black smoker mining will mean that land-based mining operations, which have immensely more potential for environmental harm, will begin to be phased out. The environmentalist movement will have thus scored a great victory. For this reason alone black smoker mining should be encouraged, though I'll be the first to march with the Sierra Club in insisting that 'oasis' black smokers that host unusual life-forms should not be mined. We geologists love the outdoors too!

And in addition to the hydrothermal vents, there are the manganese nodules that rest on the ocean floor.

Nodules lie on the seabed sediment, often partly or completely buried. They vary greatly in abundance, in some cases touching one another and covering more than 70% of the sea floor. The total amount of polymetallic nodules on the sea floor was estimated at 500 billion tons by Alan A. Archer of the London Geological Museum in 1981.

Polymetallic nodules are found in both shallow (e.g. the Baltic Sea) and deeper waters (e.g. the central Pacific), even in lakes, and are thought to have been a feature of the seas and oceans at least since the deep oceans oxidised in the Ediacaran period over 540 million years ago.

They represent totally different microecosystems from the vents.

Nodules lie loosely in the sand, but because they exist in places devoid of any other hard substrates—just muddy sediment—they end up acting like pseudo-reefs. Sponges and other sessile creatures can anchor themselves to the metallic rocks. They in turn provide habitat for a wide variety of other deep sea organisms...

And harvesting them requires a different process:

The machines mining companies are likely to use resemble giant potato harvesters. These giant 300-ton robot tractors trundle along the seafloor, ploughing through the sediment, scooping up manganese rocks. The resulting clouds of mud agitated by such a disturbance could be devastating to the fauna that live within it and in the water column.

In 2017, Hakai magazine showed a photo of a harvester (embedded at top of the post), and discussed regulatory challenges:

Officially, the nascent deep-sea-mining industry is governed by the International Seabed Authority (ISA), an intergovernmental organization established in 1996 by the United Nations Convention on the Law of the Sea (UNCLOS). The authority’s critical task is to coordinate its 168 member nations in establishing and enforcing regulations for the developing deep-sea-mining industry.

But the ISA’s teeth are just coming in, says Duncan Currie, a legal advisor to the Deep Sea Conservation Coalition, an advocacy organization. At the moment, the authority still hasn’t created an enforcement agency. In addition, “they won’t and they can’t force countries to comply with ISA regulations when drafting their own laws,” says Currie...

That the ISA has not yet landed on a set of rules puts countries such as Papua New Guinea—where Nautilus plans to open the first commercial deep-sea-mining operation—in an uncertain state. There’s no international template for Papua New Guinea to follow, says Conn Nugent, director of the Pew Charitable Trusts’ efforts to study and guide the development of seabed mining. Papua New Guinea’s Mining Act governs both onshore and offshore activities.

The ISA has also yet to determine how it will enforce regulations and respond to allegations of noncompliance. There are provisions within its mandate to create an inspection arm, says Lodge, but it has not been established because mining has yet to begin...

Besides, says Lodge, deep-sea mining is not a fly-by-night enterprise—a deep-sea-mining operation requires an investment of hundreds of millions of dollars. This means that companies will have to get money from banks, and banks want certainty. “The consequences of license denial are extremely high,” says Lodge. A company that opts to go rogue after failing to get ISA approval will quickly find itself without the financial backing it needs to operate.

The reason I'm writing this up now is because The Atlantic has just published a longread on the subject - History's Largest Mining Operation Is About to Begin.  The author is not sanguine about the future:

Today, many of the largest mineral corporations in the world have launched underwater mining programs. On the west coast of Africa, the De Beers Group is using a fleet of specialized ships to drag machinery across the seabed in search of diamonds. In 2018, those ships extracted 1.4 million carats from the coastal waters of Namibia; in 2019, De Beers commissioned a new ship that will scrape the bottom twice as quickly as any other vessel. Another company, Nautilus Minerals, is working in the territorial waters of Papua New Guinea to shatter a field of underwater hot springs lined with precious metals, while Japan and South Korea have embarked on national projects to exploit their own offshore deposits. But the biggest prize for mining companies will be access to international waters, which cover more than half of the global seafloor and contain more valuable minerals than all the continents combined...

Regulations for ocean mining have never been formally established. The United Nations has given that task to an obscure organization known as the International Seabed Authority, which is housed in a pair of drab gray office buildings at the edge of Kingston Harbour, in Jamaica. Unlike most UN bodies, the ISA receives little oversight. It is classified as “autonomous” and falls under the direction of its own secretary general, who convenes his own general assembly once a year, at the ISA headquarters. For about a week, delegates from 168 member states pour into Kingston from around the world, gathering at a broad semicircle of desks in the auditorium of the Jamaica Conference Centre. Their assignment is not to prevent mining on the seafloor but to mitigate its damage—selecting locations where extraction will be permitted, issuing licenses to mining companies, and drafting the technical and environmental standards of an underwater Mining Code...

The companies with permits to explore these regions have raised breathtaking sums of venture capital. They have designed and built experimental vehicles, lowered them to the bottom, and begun testing methods of dredging and extraction while they wait for the ISA to complete the Mining Code and open the floodgates to commercial extraction...

At full capacity, these companies expect to dredge thousands of square miles a year. Their collection vehicles will creep across the bottom in systematic rows, scraping through the top five inches of the ocean floor. Ships above will draw thousands of pounds of sediment through a hose to the surface, remove the metallic objects, known as polymetallic nodules, and then flush the rest back into the water. Some of that slurry will contain toxins such as mercury and lead, which could poison the surrounding ocean for hundreds of miles. The rest will drift in the current until it settles in nearby ecosystems...

The ISA has issued more mining licenses for nodules than for any other seabed deposit. Most of these licenses authorize contractors to exploit a single deepwater plain. Known as the Clarion-Clipperton Zone, or CCZ, it extends across 1.7 million square miles between Hawaii and Mexico—wider than the continental United States. When the Mining Code is approved, more than a dozen companies will accelerate their explorations in the CCZ to industrial-scale extraction. Their ships and robots will use vacuum hoses to suck nodules and sediment from the seafloor, extracting the metal and dumping the rest into the water.

Map of the CCZ below.  Black squares are no-mining zones; white ones are being explored for mining.
 

"We’re about to make one of the biggest transformations that humans have ever made to the surface of the planet. We’re going to strip-mine a massive habitat, and once it’s gone, it isn’t coming back.”

More at The Atlantic.  For reference: Economic minerals associated with black smokers (2006)

Addendum: Race to exploit the world’s seabed set to wreak havoc on marine life explains that seabed mining is not the only new technology threatening the oceans. 

This threat comes not just from seabed mining – which is set to expand dramatically in coming years – but from fish farming, desalination plant construction, shipping, submarine cable laying, cruise tourism and the building of offshore wind farms.

This is “blue acceleration”, the term that is used by Jouffray and his co-authors to describe the recent rapid rise in marine industrialisation, a trend that has brought increasing ocean acidification, marine heating, coral reef destruction, and plastic pollution in its wake.