The International Seabed Authority (ISA) is currently meeting in Jamaica to establish rules for the mining of manganese nodules and other metals in the deep sea. Time is of the essence: a deadline expired last weekend. Companies can now apply to the ISA for dismantling. In theory, these motions can be approved even if the ISA fails again during its session to establish rules for deep-sea mining. Pedro Martinez Arbizu, director of the Senckenberg am Meer Institute, does not believe that mining in the deep sea can be ecologically compatible.
SZ: Mr. Martinez work, You and your team are involved in the “Mining Impact” project, which aims to research whether and what damage deep-sea mining causes. Are there any results yet?
Pedro Martinez Arbizu: Yes, mining the manganese nodules with large machines would be harmful for a number of reasons. On the one hand, the manganese nodules in the mining areas of the deep sea are the only firm substrate to which animals such as corals, sponges, moss animals or anemones that need firm ground can cling. So these animals would disappear with the tubers. They wouldn’t come back either, because the tubers grow back very slowly. They were created in a process that took millions of years. The species would therefore become extinct in the mining areas.
How many different species would be affected?
This is not known, but probably very many. The deep sea is very rich in species, but there are only a few individuals of each species. When collecting animals from scuba diving, almost everyone is a different species and 90 percent of the time they are unknown. My guess is that thousands of as-yet-unknown species could go extinct locally as mining begins. We do not know if they will become extinct because very little is known about the distribution of species in the deep sea. But the area to be mined is huge.
Manganese nodules would probably first be mined in the Clarion-Clipperton Zone in the Pacific Ocean between Hawaii and Mexico.
The area is roughly the size of Europe. Various states have licenses there for areas each covering an area of 75,000 square kilometers, which is slightly more than the size of Bavaria. Mining all the manganese nodules there would take several decades. But once everything is degraded, the fauna will probably not recover from it.
Pedro Martinez Arbizu is director of the Senckenberg am Meer Institute. The deep-sea researcher is studying the effects of the manganese nodule harvest on the creatures in the ocean.
(Photo: Gritta Veit-Koehler)
Why not?
The ability of animals to regenerate in the deep sea is very low. All processes are slowed down because it is very cold, around two degrees Celsius, and because there is little food. Therefore, the animals grow very slowly and also multiply slowly. Protection concepts must therefore be considered before dismantling begins. We also assume that not only the fauna in the direct mining area is affected, but also animals in other areas.
As the?
When the nodules are broken down, the first ten centimeters of sediment are stirred up. The fine particles are carried away by the water like a cloud. The cloud of sediment then settles again in a radius of about five to ten kilometers around the mining area and bury the animals that live there. Many species will not be able to cope with this. Animals that are not completely buried will need a lot of energy to clean themselves up. Because there is little food in the deep sea, it is difficult to find the extra energy needed to do so. This could weaken the animals, which can result in their death or at least no longer reproducing. On the other hand, there are very many species that live in the sediment and are adapted to burrowing in the sediment. These animals are unlikely to be affected much. Finding that out is currently the focus of our work.
What happens if companies are about to apply for downsizing and they are approved by the ISA? Will it then be excavated immediately?
The Canadian company The Metals Company already has the technology to harvest the nodules and then transport them to the sea surface onto a ship. The Belgian GSR can harvest the tubers on the seabed, but has not yet tested technology to transport them to the top. There is also still a lack of methods for optimally processing the manganese nodules in order to extract as many metals as possible from them. The manganese nodules not only contain manganese, but also copper, nickel and cobalt, among other things.
How long will it take before everything is ready and large-scale deep-sea mining can take place?
That’s hard to say, but I’m happy to give you my personal take on it: I believe there will be more testing over the next few years. But to mine the manganese nodules on a large scale requires huge investments and the technology has to be mature enough to work 24 hours a day, 365 days a year. The machines that exist now are all prototypes. They occasionally fail and need to be repaired. With each test, experience is gained and technology improved. But in order to mine the nodules on an industrial scale, larger companies than those currently involved will probably have to get involved.
How likely is it that such investors will be found?
That depends on many factors, all of which are difficult to predict. For example, which metals will be needed in the future, whether deposits are discovered elsewhere that can be mined with less effort, and how secure the markets are. But if you decide to do it, it could start in a few years.
The ISA has been working on rules for dismantling for years. In your opinion, is it at all possible to make deep-sea mining at least halfway environmentally friendly?
It is clear that deep-sea mining is not sustainable. It will probably never be ecologically justifiable either. That’s why I don’t think we should do it for the time being. In my opinion, the precautionary break proposed by the federal government is the right way to go. We need to better understand the ecological consequences of deep-sea mining. More research is needed for this. In practice, however, another question will probably be decisive in addition to profitability: where will the metals come from in the future if they are not fetched from the deep sea? And are the other extraction methods, for example in opencast mining on land, which also destroys large areas and contaminates rivers, then morally justifiable?
The choice between two evils.
In principle yes. Unfortunately, humanity leaves a huge footprint on earth.