At a depth of 4,000 to 6,000 meters everything that is needed for climate change is lying around: manganese, cobalt, copper, nickel – the stuff that rechargeable batteries and batteries are made of. Among other things. It took millions of years for the metals to settle down there and now, in the form of nodules the size of a fist, are waiting to be “harvested”. Strictly speaking, the manganese nodules themselves are in no hurry, but companies like The Metal Company (TMC) are. The Canadians have already tested machines to collect the coveted raw materials from the deep seabed and have applied to start doing so.
That could have been granted in the Jamaican capital of Kingston. But even after a two-week meeting, the responsible council of the International Seabed Authority (ISA) could not agree on a set of rules for the exploitation of the deep sea. The little that the 36 member states agreed on was to set the long overdue “Mining Code” by 2025. Until then, no decisions should be made about applications like that of TMC.
But the sheer quantity of the suspected raw materials alone arouses desires. In the Clarion-Clipperton zone in the Pacific between Mexico and Hawaii, for example, there are so many maganese nodules lying around that up to 20 kilograms per square meter could be “harvested”. The entire Pacific Manganese Nodule Belt is larger than the European Union and contains billions upon billions of tons.
So far it is certain that the commercial mining of raw materials on the bottom of international seas would entail dangers of an unforeseeable extent for the ecosystem there. Only which one is not yet foreseeable. The deep sea is one of the last great unknown spots on this planet. Of the approximately 300 million square kilometers of seabed, just five percent have been explored.
Which, of course, does not mean that mankind would have passed by without a trace. Researchers recently found vast amounts of plastic waste – at a depth of 9582 meters. Because there are hardly any waves down there and there is also no sunlight, the waste will rot a long time before it does. Changes happen more slowly than in slow motion in the shallows of the oceans.
This was particularly impressive to see in pictures of the seabed south-east of the Galapagos Islands. There, in 1989, a team from the University of Hamburg tested the mining of manganese nodules and plowed eleven square kilometers of seabed with a kind of suction dredger. In 2016, almost 30 years later, researchers looked at what had happened in the area since then. To their astonishment they found: nothing. Nothing good anyway. The robot’s tracks, which had been milled into the sand, appeared unchanged, only the bacterial population had largely disappeared.
This is what it could look like in many places on the seabed in the future, when companies like TMC unleash their tank-sized nodular collectors on the seabed. According to a 1994 agreement, the deep seabed is part of humanity’s common heritage and the use of its resources must be for the benefit of humanity. Does this include the mining of manganese nodules, which private companies use to build environmentally and climate-friendly electric cars? So far, science has not dared to predict what possible damage the “tuber harvest” will cause.
But the function of the “collectors” worries researchers: They not only suck up the nodules, but also all the organisms that live on them and in and on the sediment. In addition, the resulting sediment clouds can cause extensive damage. Studies also warn of dangers for whales from noise and for humans from the radioactivity of the nodules.
In a series of studies, scientists have dealt with the specific effects of deep-sea mining. The “harvest areas” alone will be so huge that, with an estimated 30 years of mining, 500 million tons of muddy waste water will be produced per company. These sediments could form huge clouds of dirt with dissolved, toxic metals and be carried hundreds of kilometers across the oceans. Animals that are used to clear water, for example, would not be able to filter out the pollution. “Deep-sea mining poses a significant risk to the ecosystem at mid-water depths,” says a study from the University of Hawaii.
In view of such results, Germany is also pleading for a precautionary break in deep-sea mining. Until the environmental consequences have been better researched, a good 20 countries have now spoken out in favor of such a moratorium or even a ban. Various corporations have also joined the demands, including BMW, Samsung, Philips and Google. According to the WWF and a report commissioned by Greenpeace, deep-sea mining is not absolutely necessary for the energy and transport transition.
But the impatient Canadians at TMC are already creating facts: through agreements with the states of Nauru, Tonga and Kiribati, the company has potential licenses for three areas in the tropical Pacific. In a pilot test a few months ago, The Metal Company pumped more than 3,000 tons of manganese nodules to the surface of the sea – and it is now ready to use the harvesters on a large scale.
Sources: DPA, Spectrum of Science, “Die Welt”, Tagesschau
