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Deep-sea mining: Good or bad for our planet?

Deep-sea mining presents a complex dilemma in the push to reduce greenhouse gas emissions and combat climate change. As demand for critical minerals like lithium, cobalt, and graphite soars—needed for EV batteries, wind turbines, and solar panels—some are turning to the ocean floor, which holds vast deposits of these metals. While terrestrial mining is already underway, the seabed offers an untapped resource.

Several nations have applied to the UN’s International Seabed Authority (ISA) for permits to explore international waters for deep-sea mining, where much of the world’s critical minerals lie. However, despite years of research, our knowledge of the deep ocean remains limited. Many scientists and environmentalists warn that disturbing this fragile ecosystem could have severe consequences for marine life and the overall health of the planet.

In 2023, the ISA failed to reach a consensus on regulating deep-sea mining and now has until 2025 to establish rules that will govern whether and how countries can pursue it in international waters. Discussions on its environmental impact will be crucial in shaping the final decision. For now, the future of deep-sea mining and its potential risks and rewards remains uncertain.[1]

However, while the future of deep-sea mining is still under debate, it’s important to understand the practice and its impacts:

What is the exact meaning of deep-sea mining?

Deep-sea mining involves extracting mineral deposits from the ocean floor at depths greater than 200 meters. This vast area covers more than 60% of the Earth’s surface and is home to a diverse array of species, many of which are still unknown to science. The seabed includes a variety of geological features, such as mountain ranges, plateaus, volcanic peaks, canyons, abyssal plains, and even the Mariana Trench, the ocean’s deepest point at 11,000 meters.

While commercial mining has yet to become a reality, experimental deep-sea mining has already taken place. The process typically involves deploying vehicles to the ocean floor to cut or dredge seabed formations, then collecting mineral-rich deposits via scooping or suctioning to a support vessel, where they are stored, processed, and eventually transported to land.[2]

How much are deep-sea metals worth?

While there isn’t a complete estimate of the total value of all the resources beneath the ocean, a 2014 World Economic Forum report provided some perspective, estimating that the gold in international seabeds alone could be worth at least $150 trillion. To put that in context, it’s equivalent to roughly nine pounds of gold for every person on the planet. This staggering figure highlights just a fraction of the potential wealth hidden beneath the oceans, with vast untapped mineral deposits still waiting to be fully understood and explored.[3]

What are the environmental impacts of deep-sea mining?

The deep sea is the largest habitat on Earth, teeming with an extraordinary diversity of unique species and ecosystems, representing a rich reservoir of biodiversity. Unlike land-based ecosystems, the deep ocean remains largely unexplored and poorly understood due to its extreme conditions, high pressure, perpetual darkness, and freezing temperatures, earning it the nickname “Earth’s final frontier”. However, growing interest in deep-sea mineral deposits has led to increasing efforts to study these ecosystems, spurred by the prospect of commercial exploitation.

Research has revealed that the deep-sea environment is highly heterogeneous, with sediment and mineral nodules creating diverse habitats. So far, more than 5,000 previously unknown species have been identified in these regions, underscoring the vast biological wealth that remains to be discovered.

Despite the unknowns, some of the potential environmental impacts of deep-sea mining are becoming clearer:

Habitat destruction: One of the most immediate consequences of seabed mining is the removal of nodules and the associated sediment, which drastically alters the seafloor’s structure and chemistry. Many organisms rely on these nodules as their habitat, and since nodules take millions of years to grow a few millimeters, the recovery of these ecosystems—especially for species like sessile animals that attach themselves to rocks—is highly unlikely.

Noise pollution: Mining operations generate significant noise, both at the surface from marine vessels and at the deep-sea level from mining equipment. In the ocean, sound travels faster and across greater distances than in air, making it a key communication medium for marine life. Anthropogenic noise from mining can easily disrupt communication among sensitive species, such as marine mammals, potentially leading to disorientation and other negative effects.

Light pollution: In the deep sea, less than one percent of sunlight penetrates below 200 meters, meaning many organisms are adapted to live in near-total darkness. The artificial lights used by mining vehicles for navigation and monitoring can disturb species with highly sensitive vision, disrupting their natural behaviors and causing stress in organisms that are unaccustomed to light.

While much remains unknown about the long-term consequences of deep-sea mining on this fragile and diverse ecosystem, it is clear that the impacts could be profound and potentially irreversible. Further research and stringent regulations will be essential to balance resource extraction with the protection of deep-sea environments.[4]

Opposition to Deep-Sea Mining

Given the significant risks and uncertainties surrounding deep-sea mining, organized resistance to its industrial-scale development has gained momentum. Various parties, including the World Wildlife Fund (WWF), have called for a moratorium on extracting materials from the ocean floor. This stance has garnered support from countries like Fiji, and members of the European Parliament, along with major corporations such as Google and Samsung. There is precedent for limiting resource extraction in remote, fragile environments. In Antarctica, for instance, the 1998 Environmental Protection Protocol prohibits all mining activities, with the exception of scientific research—similar to the exploration permits issued by the ISA. Any changes to this protocol before 2048 would require unanimous agreement, highlighting the cautious approach taken in protecting such vulnerable ecosystems.[5]

What can be done?

Under the United Nations Convention on the Law of the Sea (UNCLOS), the deep-sea area and its mineral resources are considered the “common heritage of humankind.” This implies that they must be managed in the best interests of all humanity, ensuring that economic benefits are fairly shared, marine scientific research is supported, and the marine environment is effectively protected.

At the 2021 IUCN World Conservation Congress in Marseille, members passed Resolution 122, calling for a moratorium on deep-sea mining until specific conditions are met to safeguard deep-ocean ecosystems and biodiversity. These conditions include[6]:

Comprehensive understanding of risks: The potential impacts of mining must be fully assessed, and effective protections must be guaranteed.
Thorough and transparent assessments: Rigorous impact evaluations based on extensive baseline studies must be conducted before any mining begins.
Implementation of key principles: The Precautionary Principle and the Polluter Pays Principle must be applied to ensure accountability for environmental harm.
Circular economy policies: Strong policies that prioritize the reuse and recycling of minerals should be developed and implemented to minimize the need for new mining.
Public involvement: Decisions related to deep-sea mining should involve thorough public consultation at all stages.
Transparent and responsible governance: The regulation of deep-sea mining must be inclusive, accountable, effective, and environmentally responsible.

To reduce dependence on deep-sea mining, we can focus on redesigning products to minimize resource use, reusing materials, and increasing recycling efforts. In addition, research should prioritize finding sustainable alternatives to these metals, as deep-sea mining could potentially cause irreversible damage to marine ecosystems, limiting the critical benefits that the deep ocean provides to humanity.

[1] https://www.wri.org/insights/deep-sea-mining-explained

[2] https://dialogue.earth/en/ocean/6677-deep-seabed-mining-2/

[3] https://www.biologicaldiversity.org/campaigns/deep-sea_mining/pdfs/Deep-seaMiningFAQ.pdf

[4] https://www.lse.ac.uk/granthaminstitute/explainers/what-is-deep-sea-mining-and-how-is-it-connected-to-the-net-zero-transition/

[5] https://hir.harvard.edu/deep-sea-mining-and-the-green-transition/

[6] https://iucn.org/resources/issues-brief/deep-sea-mining