Findings of a recent study in Japan, published in Current Biology, had “large implications” for decision-makers negotiating regulations on proposals for deep-sea mining.

What’s happening? Deep-sea mining, the extraction of valuable metals and minerals from the seabed, has become a topic of intense debate in recent years.

Proponents argue that it holds the key to fulfilling the growing demand for essential elements, such as cobalt and nickel, required for various industries, including the rapidly growing renewables sector and electric vehicles industry.

However, concerns are mounting as scientific studies reveal the detrimental impacts on marine life and ecosystems in the deep sea. Problems arise as the International Seabed Authority (ISA), the governing body commanding the seabed in international waters, is yet to make progress in discussions concerning deep-sea mining regulations.

As the recently agreed UN’s High Seas Treaty does not cover deep-sea mining, it leaves the seabed in international waters unregulated, awaiting the ISA’s decision. Nauru’s application to mine the seabed in 2021 triggered a two-year approval process within the ISA. However, several countries have previously called for a “precautionary pause” to deep-sea mining until more research into its impacts is complete.

Impact on marine life – Marine populations of fish and shrimp have decreased by 43% in areas of the Takuyo-Daigo seamount a year after cobalt was extracted from the seabed, according to a study by Travis Washburn of the Geological Survey of Japan, who said the findings had implications for regulations on deep-sea mining.

Beyond the direct impact zones, the density of fish and shrimp dropped even further, by more than 50%. These findings suggest that the impact of deep-sea mining may be greater and expand further than initially anticipated, affecting marine ecosystems on a broader scale.

Much of the regulatory discussion concerns the rich biodiversity found in the Clarion-Clipperton Zone (CCZ), a remote region in the eastern Pacific Ocean. Polymetallic nodules in the CCZ, which hold valuable metals sought after by mining companies, serve as habitats for various deep-sea creatures.

However, mining these nodules could lead to the loss of numerous unknown and yet-to-be-described species. The consequences of such losses are difficult to predict and may have far-reaching effects on the delicate balance of deep-sea ecosystems.

Into the unknown – As deep-sea mining technology progresses, the full extent of its impact on marine life remains largely unknown. The minerals found in the seabed are essential for everyday devices such as cell phones and cars, as well as renewable technologies.

A concerted effort to reach the goals of the Paris Agreement equates to a quadrupling of mineral requirements for clean energy technologies by 2040. Hitting net zero globally by 2050 will require a six-fold increase in mineral inputs.

However, scientists have cautioned against a rush to mine the seabed, emphasising that it could take decades to fully understand the consequences on marine biodiversity. The complexity of deep-sea ecosystems, with numerous undiscovered species, makes it challenging to predict the long-term effects of mining activities with regulators admitting “humanity knows more about deep space than the deep ocean”.

Regulatory challenge – In 2021, Nauru triggered a two-year rule that obliged the ISA to finalise and adopt regulations for commercial mining by July 2023. Since then, the regulatory process has been turbulent with the head of the ISA accused of “abandoning neutrality” in favour of mining commencing.

Meanwhile, countries called for a “precautionary pause” whilst discussions were ongoing, with various companies including BMW and Volkswagen declaring they would not buy metals mined from the seabed.

Ultimately, the ISA has been unable to reach a consensus on environmental regulations for deep-sea mining in international waters and the deadline has now passed. This failure to agree on rules raises concerns that mining operations, particularly those targeting metals needed for electric vehicles, could proceed without effective safeguards in place, heightening the risks of irreversible damage to deep-sea ecosystems.

What happens now? – Having missed the 9 July deadline, the ISA is technically obligated to accept licensing applications from mining companies. To address a lack of regulation, the ISA held a three-week-long meeting at the end of July. After intense negotiations, the UN body decided it needs more time to determine a regulatory framework.

The body will now work “with a view” to adopting regulations by 2025. The meeting was fraught with geopolitical clashes. Over 20 countries and 37 financial institutions supported a proposal spearheaded by Chile, France and Costa Rica, seeking to impose a precautionary pause on deep-sea mining, a motion which was repeatedly blocked by China.

However, an agreement was reached and the pause will be on the agenda for the next ISA meeting, to be held in 2024. The decisions made over the next two years are crucial for life in our deep seas.

Source: Current Biology

The long-term ecological impacts of seabed mining on marine environments are still largely unknown and have the potential to cause irreversible damage. Deep-sea mining – extracting naturally occurring rock deposits of cobalt, manganese and other minerals at depths below 200 m – is particularly risky, considering just one-fifth of the global ocean floor has been mapped by scientists and there is limited data for nearly 80% of the Earth’s oceans. California’s state-level legislation will ensure the protection of marine habitats and safeguard coastal areas and industries such as tourism and fishing.

Following the move and together with Oregon and Washington’s existing legislation, over 7,700 square miles of US ocean will now be protected against seabed mining activities. Marine species such as the endangered coho salmon, which hatch in freshwater streams that migrate into ocean waters along the US west coast, could be particularly susceptible to disturbance from seabed mining.

California’s state waters do not contain rich deposits of battery metals commonly targeted in seabed mining operations. However, waters along the state’s south coast could see increased future interest in extracting gold, titanium, and precious and semi-precious metal deposits. Meanwhile, interest could grow toward mining for phosphorites – a component used in industrial fertiliser – in waters around Southern California.

Disturbances caused by industrial seabed mining operations can threaten delicate marine ecosystems along the seabed, including up to two-thirds of all mollusc species found in the deep ocean. Such operations could also generate excessive light and noise pollution – with the latter having the potential to stretch across 500 km of ocean and create a “cylinder of sound” from the seabed to the ocean surface. This has the potential to influence the behaviour of marine mammals, such as whales, narwhals and dolphins, which rely heavily on sound.

Interest in deep-sea mining activities is rapidly gaining interest, mostly driven by the need to decarbonise, electrify and scale up low-carbon technologies such as wind turbines and electric vehicle batteries. Therefore, some view deep-sea mining as the best solution to secure metals, which in some areas are abundantly found along the seabed. However, there are too many significant gaps in understanding the ecological impacts of seabed mining to allow exploration at present, a recent study concluded.

Others believe that the arguments promoting deep-sea mining are flawed and that deep-sea exploration is not needed for the low-carbon transition. According to researchers, future demand predictions do not consider alternative solutions that can lower the demand for mineral resources. For instance, a combination of developing innovative alternatives, improving metal recycling and repairs could mitigate industrial needs for raw materials.

Elsewhere, action is being taken to protect seabed habitats. Environmental groups are calling for a global moratorium on deep-sea mining until its impacts are better understood. The G7 countries have also agreed that strict environmental controls should be implemented for seabed mining activities.

On a country level, Palau, Fiji and Samoa formed the Alliance of Countries for a Moratorium on Deep-sea Mining in June this year and are the first countries to oppose deep-sea mining in international waters. The Pacific nations are located near the Clarion Clipperton Zone, a stretch of ocean that contains over 20 million tonnes of minerals and which is likely to see pressure for large-scale industrial resource extraction begin. Last year, New Zealand’s supreme court upheld the decision of a lower court to reject a deep-sea mining project on environmental grounds.

Source: PEW

What’s happening? Nearly two-thirds of the hundreds of mollusc species in the deep ocean could face extinction due to deep-sea mining, according to a study from Queen’s University in Belfast. The research has seen dozens of mollusc species living close to hydrothermal vents added to the red list of threatened species published by the International Union for the Conservation of Nature (IUCN). The researchers have said mining could also lead other species dependent on the vents to face extinction risk.

Why does this matter? The deep sea is the largest biome on the planet, comprising varied geomorphological features and habitats – from canyons and seamounts to cold seeps and brine pools. Hydrothermal vents, first discovered in 1977, can be found at a depth of 1,000 to 4,000 meters and play an important role in regulating ocean chemistry. They occur at volcanically active mid-ocean ridges, where seawater enters the Earth’s crust and gets heated up to 400C by hot magma. During the process, the water absorbs minerals such as copper, iron, zinc or cobalt from surrounding rocks before exiting via vent openings as hot, mineral-rich fluids. The contact with cold seawater leads to a chemical reaction and the formation of solid mineral deposits.

With about one-fifth of the global ocean floor mapped, scientists have discovered 600 hydrothermal vent sites, each hosting an abundance of diverse life forms. In the absence of sunlight, endemic microbes convert CO2 into sugar using chemical energy from the vent fluids – a process called chemosynthesis – which forms the basis for symbiotic relationships with larger organisms such as shellfish or tubeworms. These animals attract predators including crabs, zoarcid fish and octopuses, turning the vents into biodiversity hotspots.

Hydrothermal vent structures – also known as seafloor massive sulphides – are one of three types of deep-sea mineral deposits under consideration for commercial exploitation, alongside cobalt-rich seamount crusts and polymetallic nodules on abyssal plains. Researchers have now warned that mining poses a substantial threat to these unique ecosystems. Of 184 mollusc species found near hydrothermal vents, 62% were classified as threatened, while only 25 species were fully protected from extraction activities through local conservation measures. In the Indian Ocean, every single mollusc species was listed as threatened.

The new study is not the first to warn about the consequences of industrial-scale deep-sea mining. Others have pointed out that the destruction of seafloor habitat, the release of toxins and sediment plumes, as well as the noise and light pollution associated with deep-sea mining could have catastrophic long-term impacts on sensitive and under-researched ecosystems. Large-scale impacts on these ecosystems would also have implications for climate change mitigation: scientists have estimated that deep-sea bacteria could fix up to 200 million mt of CO2 in the oceans per year.

Although countries like Japan, South Korea and Papa New Guinea have started mining resources in territorial waters, the vast majority is located in international waters beyond national jurisdiction, which have not been opened to large-scale extraction. This area, estimated to contain more valuable metals than all continents combined, is governed by the International Seabed Authority (ISA) under the UN Convention on the Law of the Sea. As of May 2021, the ISA has issued 31 exploration licenses to advance the development of machines and extraction methods. By June 2023, the organisation is due to finish the underwater Mining Code, a regulatory framework setting out technical and environmental standards for the mining of materials used to produce green energy technology and electric vehicles.

Meanwhile, more than 600 marine science and policy experts, backed by the European Parliament and the IUCN, have called for a global moratorium on deep-sea mining.

Sources: Frontiers in Marine Science; The Guardian