According to the Royal Netherlands Institute for Sea Research (NIOZ), deepsea mining is still ‘fraught with many uncertainties’. As such, the organsiation feels it is far too early to proceed with commercial deepsea mining at this time.

Marine biologist Sabine Gollner of NIOZ: ‘New life forms are being discovered almost on a daily basis in the deep sea. We still hardly know what the impact of mining would be for these life forms.’

Gollner, in the role of scientific advisor, attended the International Seabed Authority (ISA) conference, last weeks in Jamaica. Agreements on exploration and possibly exploitation of the various valuable minerals on the ocean floor didn’t materialise.

Also read: In pictures: Allseas concludes deepsea mining trial with 4500 tonnes of nodules

Ecological impact

At present, the International Seabed Authority has reached agreements only on exploring of deepsea mining opportunities. Like on land, where there are flat regions but also mountains, each offering living space for distinct life, also in the deep sea different ecosystems are found, of which three are known for their metal resources: abyssal plains with polymetallic nodules, hydrothermal vents with polymetallic sulfides, and seamounts with cobalt-rich crusts.

On the abyssal plains in a region called the Clarion-Clipperton Zone in the Pacific Ocean, seventeen countries have exploration areas of 75,000 square kilometres each, which is almost twice the size of the Netherlands. For now, only data are collected there on how many manganese nodules are on the bottom and what kind of life lives at the bottom.

In 2021 and 2022, the first tests with mining equipment were conducted at a depth of four kilometers. NIOZ is participating in the European “JPI Oceans Mining Impact project” (Joint Programming Initiative Healthy and Productive Seas and Oceans), which is looking independently at the ecological impact of the practical tests by the Belgian mining company DEME-GSR.

Also read: How TMC monitors the environmental impact of nodule collection trials

Slow recovery

Among other things, the researchers are looking at the environmental impacts of removing the manganese nodules, removing the top layer of the ocean floor and of the huge sediment plumes that are created during the work on the bottom.

Gollner: ‘Systems that have been created over millions of years are being turned upside down. Manganese nodules, for example, grow at a rate, or better, an inertia of a few millimetres in a million years. So, when those nodules are removed, it will also take literally millions of years for that ecosystem to return to the state before the mining activities.’

She adds: ‘The sediment plumes may cover an area of up to ten times the size of the mined area. Due to the sediment plumes, the environment and therefore the animals become covered with sediment. Life in the sediment is estimated to take several decades to hundreds or even thousands of years to recover. Mining-impacts for the life in the water are almost unknown.’

Also read: VIDEO: New NIOZ research vessel Wim Wolff moves out of production hall

Thousands of life forms

Gollner is researching the literally thousands of different life forms that live around the beds of valuable metals.

‘Of all the life we encounter there, around ninety per cent is still unknown to science. Apart from their intrinsic value, deepsea life is also important. Organisms in the deepsea are part of the carbon-cycle and they form marine genetic resources. Many deepsea organisms are already indirectly part of our life, for example as medicine or for bio-inspired materials. Moreover, there is extreme diversity. Organisms that you encounter in one place may be totally unknown in the next area. That also makes investigating the possible impact of mining very difficult,’ Gollner states.

Also read: Nodules collected 4.5 kilometres below the surface in deepsea mining trial

Scientific advice

In Jamaica, the various countries within the International Seabed Authority were discussing legislation to regulate future mining of metals on the seabed. In this process, Gollner and colleagues provided scientific advice to lawyers negotiating a treaty about licensing and controlling mining activities.

‘International scientists do agree that it is really too early now, to start with exploitation of the valuable metals on the ocean floor,’ Gollner states. ‘How long it will take until one knows enough about whether metals can be harvested in an ecologically responsible way in the deep sea, or not, is still a matter of debate. Some talk about a precautionary pause of six years, others of thirty years.’

From July 10th, the ISA council will meet again in Jamaica to find an agreement on the future of deep-sea mining.

Picture: Nodules on the seafloor with sea anemone and ophiuroid, photographed during a joined expedition of GEOMAR and NIOZ (photo: GEOMAR, ROVKiel6000).

Also read: Dutch maritime industry outraged that Spanish yard will build new NIOZ ship