Why is manganese nodule mining so controversial?

For some, they are a beacon of hope: manganese nodules that lie close together on the seafloor, especially in the Pacific Ocean. Mining it could provide important raw materials for electric cars, for example, but it also poses risks.

They lie like cobblestones at a depth of several thousand meters. Polymetallic nodules containing manganese, copper, nickel and cobalt. Raw materials that are becoming increasingly important for electric mobility and wind energy expansion. Christian Müller, head of the Department of Marine Resources Exploration at the Federal Institute for Geosciences and Natural Resources, or BGR for short, is certainly one of the best experts on the subject in Germany.

BGR has already made an exploratory tour several times in the Clarion-Clipperton area between Hawaii and Mexico, where the tubers are stored, among other things, and where Germany has a licensing area. Its area is 4.5 million square kilometers, approximately the size of the European Union.

Germany as a warning

Because the International Seabed Authority, as administrator of this area, has not yet established any regulations for deep-sea mining, countries and companies have so far only been able to conduct research and not harvest anything: “So we can reduce the copper requirements,” says Müller, whose facility is part of Federal Ministry of Economy, “In Germany 6%, nickel requirements 51% and cobalt requirements 80%.”

Germany will become more independent from Congo and China. But despite these advantages, the Federal Republic spoke in favor of a moratorium or precautionary halt to deep-sea mining because the consequences on the environment have not yet been adequately examined. More than 20 ISA member states and some major companies such as BMW, Google, Samsung and Volvo have joined this position.

Japan as a silent driver and beneficiary

Japan, like Germany, is poor in raw materials, but scientists from JAMSTEC, the Japanese Agency for Marine and Geological Science and Technology, have discovered a rare earth sludge in its economic zone. Yoshihisa Kawamura is the project team leader and says with a sly smile: “If we recover these elements from the deposit, they will be very good mineral resources for Japan.”

Although technically difficult to penetrate to depths of up to 5,000 metres, there have already been attempts using a similar tube to lift an estimated 12 tonnes from the sea floor. According to Kawamura, Japan could use this to cover its needs for raw materials for electric cars and wind power plants for decades and even supply other countries.

To get things started soon, the Japanese government has provided additional funding for research in the supplementary budget. Japan also wants to become more independent from China, from which it previously imported rare earths.

Like Germany, Japan has licenses in the Clarion-Clipperton area but does not support the moratorium. A local company has already obtained the exclusive rights to process the first 1.3 million tons of manganese nodules. To this end, the company has signed a binding letter of intent with Canadian mining company Metals Company, the commercial engine of deep-sea mining.

The Kingdom of Tonga between rejection and hope

The Kingdom of Tonga in the South Pacific also cooperated with the Minerals Corporation or one of its subsidiaries. The island nation wants to rehabilitate its faltering budget and is acting as a sponsor of manganese nodule drilling in the Clarion-Clipperton area.

If this helps fishermen earn more income, fisherman Roy Pani thinks it is a good idea. “Otherwise we should leave it alone.” Sam Phiao is the head of the Fishing Association and fears for his country's fish wealth, which is considered one of the most important sources of income.

In addition to fishing, this also includes whale watching tours. But whales could also suffer if large harvesters trundled loudly across the seafloor — even if far away — to harvest manganese nodules. “Whales are very sensitive to noise and noise,” says Tokiya Tatafu, who has been offering whale-watching tours for 20 years.

Exhibitions: Tonga does not benefit

Early in 2020, the Tonga Civil Society Forum, an association of 144 non-governmental organizations, called for a ban on deep-sea mining. Drew Havea is the president. Above all, he fears asylum claims from other Pacific countries if the withdrawal of sediment that could arise during mining has an impact on fish stocks.

This could happen if the International Seabed Authority sets strict rules for deep-sea mining. In addition, deep-sea mining is not sustainable: “Once the manganese nodules are extracted, there will be none left in Tonga, the processing will be done elsewhere, and no jobs will be created.”

Proponents: Tonga has no alternative

The head of the Tonga Geological Survey and Minister of State in the Ministry of Lands and Natural Resources, Taniela Kula, does not dispute this. He sees deep-sea mining as just an opportunity for his country's population of 100,000 people: “We have no other sector that can boost our economy. Tourism is out of the question, we only have a few hundred hotel beds, and we cannot keep a crew of gold.” International Conference Therefore, we must “transform into a sector that will grow our economy, and the minerals found at the bottom of the sea have the potential to achieve this.”

Kula says Tonga will receive US$2.50 for every tonne of manganese nodules lifted, and up to three million tonnes could be lifted annually.

The impact on the environment is controversial

He believes that the impact on the environment is minimal. Lina Tolani sees the same thing. The environmental engineer made two exploratory trips to the Clarion-Clipperton area and, among other things, took sediment samples there, with funding from the Canadian Minerals Corporation. Contrary to what is often claimed, the sediment clouds that can form during mining will not move kilometers, but will rise only 20 meters from the sea floor, but will then be pushed down again by gravity, she says. They determined this using remotely controlled vehicles and sensors in the test field.

Proponents and critics have now presented countless studies, but it has not yet been decided who will emerge victorious in the end. The ISA spring meeting is followed by another meeting in the summer. Then the first regulations can be determined.