Underwater mines: biologists concerned

Underwater deposits, which have been known since the 1970s, have not yet been significantly exploited due to the collapse of the metal market in the 1980s and 90s, technical challenges and the lack of clear environmental regulations for their exploitation in the deep seas.

In recent years, demand for metals, particularly for high-tech applications (e.g. the manufacture of mobile phones and solar panels), and the fear of an imminent shortage of these metals has sparked the interest of mining companies for extracting deposits from the seabed.

What are ocean mineral reserves? Will mining them be profitable? There are still many unknowns.

The International Seabed Authority (ISA) the UN agency that regulates the exploitation of the seabed in international waters, is currently preparing a regulatory framework for mining, including environmental protection measures, which should be approved by 2020.

The ISA is also responsible for issuing mining claims. Since 2001, 28 mining exploration permits have been allocated to countries and commercial contractors covering a total area of ​​more than one million square kilometres – almost the size of the province of Quebec – in the Atlantic, Pacific and Indian Oceans.

The ISA’s Legal and Technical Commission, composed of 30 mining, scientific and legal experts, examines permit applications and ensures compliance with environmental standards. The deliberations of the Commission are for the most part confidential. Apart from these thirty experts, nobody knows what the mining companies have discovered under the ocean or the results of the environmental impact assessments. Some environmental groups are furious that just 30 or so individuals have the right to take decisions behind closed doors concerning half of the world’s surface area and are requesting that the deliberations be made public.

Apart from these thirty experts, nobody knows what the mining companies have discovered under the ocean or the results of the environmental impact assessments.

Almost nothing is known about the biodiversity of the abyssal plains – which are home to the polymetallic nodules targeted by miners – and the deposits of hydrothermal sulphides created by underwater geysers, which are also rich in metals. However, we do know that the resilience of these ecosystems is low. In the deep seas, native species are often slow to recolonize disturbed habitats. A study published in Scientific Reports in 2016 reveals that tracks left 37 years ago by machinery in the Clarion-Clipperton Fracture Zone in the Pacific Ocean between Mexico and Hawaii – which contains the highest concentrations of nodules in the world – are still very visible and that fauna in these tracks is 70% less abundant than in undisturbed sites.

Scientists do not fully understand the magnitude of the damage caused by deep-sea mining. This activity will stir up sediment, which might contaminate the water column and travel great distances. Mining waste will be discharged in the ocean. The noise of underwater craft and mining vessels will be added to that already generated by human activities. What will the impacts be of one mine, two mines, twenty mines on the pelagic ecosystems and the rest of the ocean? How will whale habitats be modified? In the absence of answers to all these questions, will ISA be capable of implementing a mining regulation by 2020 that effectively protects local and global biodiversity?