Opinion: Deep sea mining

Dr Sebastian Unger and Dr Sabine Christiansen are senior research associates at the Institute for Advanced Sustainability Studies

You may have heard about minerals on the bottom of the ocean. The UK Government sponsors several exploration contracts for UK Seabed Resources (a subsidiary of the American aerospace and security company Lockheed-Martin) in the Pacific Ocean to look for them. These minerals come from the so-called ‘Area’, the deep seafloor beyond the limits of national jurisdiction.

This ‘Area’ and its mineral resources represent the ‘common heritage of mankind’. The Law of the Sea Convention, UNCLOS (1982) determines that rather than a free-for-all, this last piece of ocean floor outside the jurisdiction of any coastal state belongs to mankind as a whole and shall be administered in such a way that benefits all, considering in particular the needs of developing countries. An organisation made up of all 168 UNCLOS signatories, the International Seabed Authority, is responsible for regulating access to the Area. Its mandate includes the development of mineral resources for the benefit of mankind, and also development measures to protect the marine environment.

So, what does ‘common heritage of mankind’ mean, and why might there be a problem? The original idea was one of solidarity and transparency, designed to ensure that marine mining could enable newly decolonised developing states to catch up with industrialised states. But, it does not appear that the promises encapsulated in the phrase are being honoured.

There is little transparency at the International Seabed Authority, and in the rush to make deep-sea mining viable, neither the provisions relating to the protection of the environment nor the benefit sharing regime have been elaborated on. The financial regime being discussed currently doesn’t take into account the value of lost ecosystems and it will not generate money for benefit sharing. Thirty contracts for mineral exploration covering nearly two million square kilometres of seafloor in the Pacific, Indian and Atlantic Oceans have now entered into force. Of these, 18 are for polymetallic nodules, seven are for polymetallic sulphides and five are for cobaltrich ferromanganese crusts. Each of these mineral types was formed by the accretion of elements from seawater over millions of years and are part of several very special ecosystems: nodules are found on the sedimentary deep-sea floor at 4,0006,000m depth, sulphides accumulated from precipitates of hot venting fluid at hydrothermal vents, and the crusts predominantly coat the rocks of seamounts. All these environments are located in the subtropical oceans; they are rich in biodiversity, functionally important, and crucially, they are poorly known.

The scale of biodiversity loss to be expected from commercial-sized seabed mining is also unknown: the affected environments are vast, difficult to explore and costly to survey; there is only basic understanding of the species present and overall ecosystem functioning; and mining technologies are being developed under the veil of intellectual property protection. However, on top of the degradation of ocean ecosystems due to the effects of fishing, pollution and climate change, deep seabed mining could potentially inflict considerable direct and indirect harm. A single manganese nodule mining operation requires the digging up of 200

800 square kilometres of deep-sea floor per year for 30 years, and the sediment plumes resulting from these mining activities will affect the wider ecosystem in a much larger area. Given this, what could be the benefit of deep seabed mining?

The most popular argument is that future generations could benefit because the minerals recovered from the seafloor will enable the transition to low-carbon energy and transportation systems. Current projections assume that a global transition to low-carbon energy technologies will lead to increased demand for certain minerals, at least until the circular economy has developed. However, new land mines are already under development to meet the demands of renewable energy development (e.g. for cobalt, copper, lithium, rare earths, nickel), and it appears very unlikely that deep seabed mining will replace any of these.

As there will be no significant financial or other benefit for mankind, nor substantial demand for the minerals recovered from the seafloor – how could the idea of a common heritage of mankind truly be realised? The deep ocean is a treasure trove of natural wonders and ecological miracles: species with hitherto unknown abilities of survival and yet extreme sensitivity to disturbance. Why not save this world from mining, preserve it for future generations while further investigating this inaccessible, dark, high pressure world?