seabed mining

Our need for metals and minerals for construction, batteries and electronics is growing exponentially (the International Energy Agency predicts that between 2020 and 2040, demand for copper will triple, for manganese will increase 8 times, for nickel 19 times and for cobalt 21 times) and as land-based resources are either running out or found in areas of conflict or with poor human rights protection, a new push to mine the resources of the deep seabed has emerged. Polymetallic nodules, ferromanganese crusts and polymetallic sulphides, rich in minerals, metals and rare earth elements like manganese, cobalt, nickel, copper, gold or zinc, have formed there over millions of years in depths of up to 4-6,000 metres. It is thought that around 500 billion metric tonnes of polymetallic nodules can be found on the seabed of the Pacific, Atlantic and Indian oceans; off the coast of Hawai’i, the Clarion Clipperton Zone between Mexico and Hawaií alone is thought to contain several billion metric tonnes of nodules, with nearly twice as much nickel (along with three times as much cobalt and significantly more manganese) than all the world’s land-based reserves combined. For more information on where they can be found see the Royal Society’s map of ocean resources.

• Polymetallic nodules are usually between 2 and 15 cm large, they contain manganese (29%), iron (6%), nickel (1.3%), copper (1.15%), cobalt (0.25%), trace metals and rare earths, and occur over extensive areas of abyssal plains at depths of 4 to 6,500 metres. They develop extremely slowly often around a shark tooth or a whale ear bone: it takes a million years to grow 20-25 mm.

• Ferromanganese crusts, which are rich in cobalt, precipitate onto nearly all rock surfaces in the deep ocean that are free of sediment (mainly seamounts), gradually building layers 1-260 mm thick at a rate of 1-5 mm per million years. Crusts occur at depths of about 800—2,500 metres, mainly in the Pacific Ocean. 

• Polymetallic sulphides are an accumulation of minerals such as sulphur and metals (iron, zinc and copper). The heaps sometimes exceed 100 metres in diameter and tens of metres in height. Between 10 and 40,000 years are needed to form a deposit of 100 metres in diameter and 50 metres in height.

Regulation

States are of course at liberty to mine any seabed resources found on the ocean floor under their jurisdiction. Most areas where seabed minerals have been found lie however in the deep ocean beyond national jurisdiction. Under the UN Convention on the Law of the Sea, the non-living resources of the Area (the seabed and ocean floor beyond national jurisdiction) are deemed the heritage of humankind. The Convention created the International Seabed Authority (ISA) to administer these resources.

Since it took up its work in 1994, the ISA has been working with States Parties to UNCLOS to draft a mining code, aiming to establish a regulatory framework for the mining regime. In the meantime, the ISA has entered into a number of contracts with States for exploration of the Area, looking into the feasability of mining seabed minerals and the effect this will have on the marine environment. Once the code is in place, the exploration contracts will be transferred into exploitation contracts.

The ISA provides 5-7 year licences to States Parties to UNCLOS to exploit resources in the Area, charging licence fees (US$500,000 per licence) which are meant to cover the costs of running the ISA, and will administer the future distribution of any revenue from exploitation. The ISA has so far approved exploration contracts covering more than 1.3 million square kilometres of the seabed in the Pacific, Indian, and Atlantic oceans. These include 19 for polymetallic nodules, 7 for polymetallic sulphides and 5 for cobalt-rich crusts, as set out on the ISA website.

Impact

Environmental organizations are increasingly concerned about the negative impact of mining on marine ecosystems, which include:

• destruction of seabed life and habitats;

• creation of large underwater plumes of sediment; and

• creation of chemical, noise and light pollution arising from mining operations.

The effects of mining on the deep-sea ecosystems may last many decades. The 1989 DISCOL deep-sea disturbance experiment in the Peru Basin in which 78 plough tracks were made by an 8-metre wide metal frame fitted with ploughs and harrows in the nodule field south of the Galápagos Islands provides evidence of this impact. In 2015, 26 years later, a research vessel returned to the site to find the plough tracks clearly visible and devoid of life, showing clearly that the marine ecosystem had still not recovered from the decades-old intrusion.

Research

The European JPI-Oceans joint project ‘Ecological Aspects of Deep-Sea Mining’, also known as MiningImpact, is run by the GEOMAR Helmholtz Centre for Ocean Research Kiel with 29 other marine science, research and educational institutions from 9 European nations and the ISA. The project is split into three phases:

• Phase 1 ran from 2015 to 2017 and investigated small-scale disturbances of the seafloor, aiming to assess the recovery of the DISCOL experimental area in the Peru Basin in terms of the ecosystem status, and the biogeochemical situation of the area by comparing disturbed with adjacent undisturbed sites.

• Phase 2 ran from 2018 to 2022, and was devoted to the industrial test of the prototype nodule collector system of the Belgian contractor DEME-GSR. The test harvested nodules from the seabed in the Belgian and German contract areas of the Clarion Clipperton Zone and collected independent scientific information on the environmental impacts of the operation. The focus was on quantifying the temporal dynamics and characteristics of the suspended sediment plume, the spatial footprint of the deposited sediment blanket, and the induced effects on the abyssal ecosystem. 

• Information on phase 3 is not yet available.

According to the GEOMAR website, MiningImpact scientists are making recommendations to inform the negotiators of the Mining Code in order to develop environmental standards and options for minimizing large-scale and long-lasting environmental damage.

Calls for a moratorium

As the ISA pushes forward with the mining code, calls for a moratorium on seabed mining are getting louder. The deep sea is still very much an area of the unknown but we do at least now know that it is teeming with life. It is becoming clear that each area, whether a submarine mountain or abyssal plain, maintains an ecosystem with species endemic to that particular area and that it is not safe to work on the premise that if an area of the seabed is allocated to a mining project, any species destroyed there will still thrive elsewhere. Life forms destroyed may well be endemic and mining may destroy species before they are even identified. In order to evaluate the impact of seabed mining, supporters of a moratorium call for further research into deep seabed ecosystems. Indeed, experts are arguing that the obligations to protect the marine environment laid down in Part XII of UNCLOS should override any destructive extractive activities and that it is therefore our duty to pause seabed mining until the correct environmental protective strategies can be put in place.