Raw materials from the seabed: the controversy surrounding deep-sea mining

Munich, 28 June 2024

Whether energy generation, communication or mobility: technology needs metal resources. The concept of the circular economy also addresses an increased demand. To this day, ores for the extraction of metals come from continental deposits. However, they can also be found in the deep sea, at the bottom of the oceans. Which raw materials can be tapped there? Who is currently interested in deep-sea mining? What risks to ecosystems are associated with large-scale interventions at depths of thousands of metres? These and other questions were the focus of acatech am Dienstag on 25 June in Munich.

After the space race, are we now experiencing the race to the deep sea? With this question, acatech President Jan Wörner opened the panel discussion on 25 June at the acatech Forum on Karolinenplatz. According to the former ESA Director General, tapping into the deep sea is an interesting endeavour for many economies due to the raw material deposits found there – also in view of the strategic sovereignty that countries can gain as a result.

Mining at a depth of several thousand metres

In his introductory lecture, Matthias Haeckel from the GEOMAR Helmholtz Centre for Ocean Research Kiel emphasised that all metal ores are currently still being mined on the continents. However, in order to secure supplies, the oceans have repeatedly become the focus of governments and raw materials companies in recent decades. However, many questions about potential ore mining in the deep sea remain unanswered to this day.

The public debate centres primarily on manganese nodules. These are spherical or cauliflower-shaped ore nodules that are usually found at depths below 4,000 metres on the large deep-sea plains. In addition to manganese, they also contain iron, copper, cobalt and nickel. The largest deposits are currently found in the central Pacific, covering an area as large as half the size of Europe.

Matthias Haeckel reported that considerations and explorations are already at an advanced stage. In order to mine economically, an area of several hundred square kilometres would have to be worked every year – comparable to the area of the state capital of Munich. This also highlights the challenges of deep-sea mining: the ecosystem on the deep-sea floor in areas with a significant abundance of manganese nodules harbours a diverse fauna that is yet unknown to us.

The International Seabed Authority (ISA) manages the entire seabed outside the Exclusive Economic Zones (200-mile zone) of individual countries. To date, the ISA has issued 18 research licences for the exploration of manganese nodule fields in the Pacific. However, there are no mining licences yet, that would only be the next step, explained Matthias Haeckel. The environmental impact of mining is now being analysed using the prototype of a manganese nodule collector (expeditions in 2019, 2021 and 2022). This machine acts like an ‘underwater vacuum cleaner’, stirring up sediments in a layer of a few centimetres – and thus fundamentally changing the entire area infused with fauna. The effects of these interventions and the sediment clouds generated – also in the longer term – on the ecosystem are still being investigated. Matthias Haeckel concluded his presentation with the key question: How much and what kind of deep-sea mining is acceptable to ensure the protection of the deep sea?

Opportunities…

Leonhard Weixler, Head of Maritime Technologies at BAUER Maschinen GmbH, began his presentation with two rock samples he had brought along: a manganese nodule and a piece of massive sulphide, which also comes from several thousand metres under the sea and contains valuable metals such as copper, zinc, gold and silver.

Leonhard Weixler and his company for specialist foundation engineering equipment are interested in mining the latter. The company has been looking for potential for innovations on the seabed for around 15 years. In contrast to the mining of manganese nodules, much smaller areas need to be worked on for the mining of massive sulphide, which is more environmentally friendly as deeper drilling takes place on a smaller surface area, thereby minimising the effects on the ecosystem.

Leonhard Weixler sees great potential here, also for Germany as an industrial location. As Chairman of the Board of the DeepSea Mining Alliance, he wants to support innovations in deep-sea mining through research. He considers it inappropriate to criticise deep-sea mining per se because manganese nodule mining is seen as causing major ecological problems. Accordingly, he argued in favour of environmentally friendly, ‘minimally invasive’ mining. Germany must also play a greater role in the development of standards and regulations. The opportunities that the deep sea offers should be seized, he stated.

…and the risks of deep-sea mining

Jan Pingel from the Oceania-Dialog, an association of NGOs and church organisations, is generally critical of deep-sea mining. He argues that we know very little, e.g. about the ecosystems there, and would only exacerbate the ‘multiple crises of the oceans’ (global warming and acidification of the oceans, plastic waste, coral extinction, …). Although Germany is not directly affected by these crises, it is the people who live off the sea – in Pacific regions, for example – who are affected. Deep-sea mining would not solve any problems. Accordingly, there are many ecological and socio-political arguments in favour of a moratorium on deep-sea mining and conducting more marine research instead.

The controversy remains

The basis for the controversy surrounding deep sea mining is, on the one hand, the different assessments of the current raw material requirements of our technology-dependent society (increase in times of energy transition and growing communication infrastructures vs. hopes for a circular economy and less raw material-intensive technical solutions). On the other hand, there are the different scientific positions regarding the ecological and social risks of deep-sea mining. This complicated situation could also be observed at acatech am Dienstag on 25 June: Should there be a pause in deep-sea mining in line with the precautionary principle, or would further research into deep-sea mining in particular pave the way for environmentally friendly innovations in this area?

Neither the panellists nor the audience were in agreement. But that was not the aim of the event, as moderator Barbara Hepp, Director of the Evangelische Stadtakademie München, the event’s cooperation partner, made clear at the end. Rather, as her colleague Thomas Zeilinger, the representative of the Evangelical Lutheran Church in Bavaria for ethics in dialogue with technology and science, added, the aim was to shed light on a current, controversial topic from the field of ‘technology and society’ from various perspectives and to raise public awareness.

Further information

Deep Sea Sampling

Thematic network energy and resources