Remote-controlled machines weighing more than 200 tons working on the ocean floor, at a depth of 1,500 m, to recover zinc sulphide, copper or gold released in the black smoke from hydrothermal vents. With Solwara 1, an underwater mine scheduled to start in early 2019 off the coast of Papua New Guinea, Nautilus Minerals aimed to be the first deep-sea miner.
The Solwara 1 project has still not started and the Canadian mining company in charge of its operation has since gone bankrupt. But will we soon begin to exploit the bottom of the oceans with a view to raising its mineral resources?
A mining code under discussion for the high seas
The vision thrills the NGOs who will seek to push the subject to the table of the One Ocean Summit which opens this Wednesday in Brest. “A few weeks before a new meeting of the International Seabed Authority (AIFM) where several countries are pushing for the adoption from 2023 of a mining code which would open the door to the exploitation of the seabed in the high seas. [cette partie des mers et océans n’appartenant à aucun pays] “, explains François Chartier, campaign manager “Oceans” at Greenpeace France. For its part, the NGO calls for a moratorium on the exploitation of deep-sea funds, as already requested by the International Union for the Conservation of Nature (IUCN) this summer, in Marseille, during its world congress. ““The time at least to determine more precisely the impacts that such an activity would have on underwater ecosystems”, slips François Chartier.
The discovery of these underwater deposits does not date from today. “That of a first hydrothermal spring dates back to 1977, near the Galapagos, before they were found everywhere along the ocean ridges [ces chaînes de montagnes sous-marines] “, recounts Jérôme Dyment, director of research at the CNRS at the Institute of Physics of the Globe in Paris, specialist in marine geosciences. It is one of these deposits that Nautilus Minerals planned to exploit. Jérôme Dyment describes them as gushes of hot water coming from the depths and charged with metals after circulating in the rock. “Suddenly, this water goes from several hundred degrees to 2°C, the temperature at the bottom of the oceans, he explains. A temperature shock that transforms the metals it carries in the liquid state into particles that end up accumulating and forming sulphide clusters. »
Potentially immense resources?
So much for hydrothermal sulphides, rich in base metals (copper, zinc, lead), precious metals (silver and gold) or even rare metals. Another deposit arouses keen interest: the polymetallic nodules found this time in the oceanic plain and at greater depths, up to 6,000 m. “These nodules are formed over a very long time from impurities that have settled at the bottom of the oceans, says Jérôme Dyment. Typically a tooth that a shark would have knocked out thousands of years ago. This tooth will become a core around which minerals of all kinds will gradually crystallize until they form a ball the size of a potato. This is essentially made up of manganese but also contains copper, nickel, cobalt and even rare metals (lithium, thallium, molybdenum, tellurium, etc.).
These underwater mineral resources are potentially immense. A 2014 report by the CNRS and the French Research Institute for the Exploitation of the Sea (Ifremer) estimates “the total weight of nodules in the Clarion-Clipperton zone alone, the richest in the Pacific (15% of the surface of the Pacific Ocean), to 34 billion tonnes**”.
Renewed interest after decades of neglect
Billions of tons all the same far from being easy to get and therefore, not necessarily interesting, economically, to exploit. For this reason, moreover, these underwater deposits remained in relative oblivion for decades. Mickaël Lodge, secretary general of the AIFM, notes a renewed interest in recent years as pressure increases on terrestrial deposits. Both to meet the needs of a growing and urbanizing world population and to ensure the development of new technologies (electric vehicles, wind turbines, solar panels, etc.) at the heart of the energy transition.
A pretext, denounces François Chartier. Above all, he mentions “technological progress which makes the exploitation of the seabed increasingly feasible and thus whets the appetite of a growing number of players. Mining companies, but also para-oil companies seeking to diversify their activities. »
Countries are also pushing behind. This is the case of small island states (Papua New Guinea, Nauru, Kiribati, etc.) which see a significant financial windfall in the exploitation of the mineral resources of their territorial waters or of concessions on the high seas obtained from the AIFM. and whose management they entrust to private companies. This is also the case of major economic powers for which the mining of the seabed is a means of escaping the dependence of China in the supply of strategic metals. “Japan in particular”, quotes Jérôme Dyment.
France in the game?
Of the thirty offshore exploration permits granted by the AIFM since the early 2000s, France has obtained two. “One in a zone with nodules in the Pacific, another in a zone with sulphide heaps south of the Azores (Atlantic), explains Pierre-Marie Sarradin, researcher in biogeochemistry at Ifremer, mandated by the French State to carry out exploration missions in these two areas. “It is good at this stage of exploration, insists the scientist. And to assess the mineral resources of these two areas, the state of the ecosystems today and the impact that deep-sea mining would have on them. Then, finally, to determine the economic feasibility and the extraction methodologies. But, to date, Ifremer is still on the first two questions. »
Clearly, France would not consider moving on to the exploration phase for several years and on the condition that it be without serious impact on the environment. It is this reassuring position that the government is displaying, particularly within the framework of the One Ocean Summit. For its part, Greenpeace recalls that France could have sent a strong signal by voting for a moratorium on the exploitation of the seabed adopted at the last IUCN World Congress. What she didn’t do.
Mining exploration in deep waters = plowed seabed, fantastic biodiversity threatened, disruption of the #weather further aggravated…
🤑 With the support of@EmmanuelMacron
🔴 There is still time to prevent this drama, but it is urgent
⤵️ Thread #deepseamining #OneOceanSummit pic.twitter.com/83y6qH0Pr8— Greenpeace France (@greenpeacefr) January 31, 2022
“Like plowing a meadow with a plow”
“However, we currently know very little about the impacts that extraction techniques would have on the ecosystems present in the abyss,” insists François Chartier. For the nodules, for example, “the envisaged solution would consist in sucking up the ocean floor over ten centimeters via a system of pipes and hydraulic pumps, explains Jérôme Dyment. Then, on board a boat on the surface, to sort this mud, recover the nodules and send the rest back to the depths”. “It’s as if you were plowing a meadow with a plow with a very high risk of killing all the life that lives on this ocean floor”, he compares then. Admittedly, this exploitation would take place on small surfaces on the scale of the oceans. “But it is not clear to what extent the sediments released in the abyss could be carried away by the currents and cover much larger areas than those exploited and suffocate the organisms which live there”, adds the campaign manager “Oceans” of Greenpeace.
One more reason for the NGO to call for this moratorium. But even if this reprieve were obtained, nothing would prevent countries from exploiting the deposits in their own waters. Norway, for example, is considering granting the first licenses to exploit its seabed from 2023.