The UN Ocean Conference is a critical opportunity to protect the ocean from deep-sea mining

The crucial conference in France comes after Trump ordered the US to pursue deep-sea mining with potentially damaging consequences. A moratorium is needed.

Expert comment Published 10 June 2025 4 minute READ

Dr Patrick Schröder

Senior Research Fellow, Environment and Society Centre

The UN Ocean Conference is taking place in Nice this week at a crucial moment for the world’s oceans, as the US and other countries appear set to accelerate deep-sea mining operations with potentially irreparable damage to marine ecosystems.

The conference, co-hosted by France and Costa Rica, aims to deliver on the UN’s Sustainable Development Goal (SDG) 14 – to ‘conserve and sustainably use the oceans, seas and marine resources for sustainable development.’ To succeed, delegates must agree on and deliver concrete and ambitious action to halt ocean degradation, protect marine ecosystems, and ensure the sustainable use of ocean resources. 

But the window to achieve this goal is rapidly narrowing. Rising global temperatures, worse-than-thought levels of acidification, the destruction of marine ecosystems and overfishing have all already caused severe damage. These threats now risk being compounded by the potential rapid increase in deep-sea mining. 

Deep-sea mining

Deep-sea mining is the process of extracting minerals from cobalt and manganese-rich crusts and rocky deposits called polymetallic nodules, which lie on the ocean floor in depths of 4,000 to 6,000 metres. They are rich in metals like nickel and copper and other critical minerals, which are used in batteries and other electronics and needed for the energy transition. 

So far, deep-sea mining has only been undertaken on a small exploratory scale. But this is now at risk of changing. 

The UN conference is taking place just over six weeks after President Donald Trump issued an executive order that granted concessions for seabed mining. Titled ‘Unleashing America’s Offshore Critical Minerals and Resources,’ the order states that the US has a ‘core national security and economic interest’ in developing and extracting seabed mineral resources. 

Scientists have warned that deep-sea mining could devastate entire ecosystems.

Alongside the US, Norway initially approved commercial exploration of deep-sea mining in early 2024, but its plans were suspended in December that year after significant domestic opposition from political and civil society groups.

These unilateral moves to issue mining licenses and accelerate commercialization risk triggering a ‘race to the bottom’ (quite literally). Other states such as Canada, China and South Korea – alongside private actors – could now rush to stake claims on the seafloor. Russia is also eying deep-sea mining as part of its Arctic and the Northern Sea Route, which are key components of its broader geopolitical strategy. 

Some estimate potential deep-sea mining profits of up to $20 trillion, initially mostly channelled to private mining companies. But these potential profits are outweighed by long-term net costs, especially the high price of restoring damaged seabeds. Studies show that when the full environmental and economic impacts are considered, the economic case for deep-sea mining is not compelling and is unlikely to be financially viable for most actors.

Unknown ecological consequences 

The extent of the impact of deep-sea mining on a large scale is unknown. But scientists have warned that deep-sea mining could devastate entire ecosystems by physically destroying the seafloor and smothering marine life with plumes of sediment. 

While proponents argue deep-sea mining could have the positive affect of replacing mining for critical minerals on land, it is more likely to just create a new frontier of ecosystem degradation in the deep ocean.  

The extraction process involves vacuuming up the seabed’s surface layer (along with all the organisms living within it), causing direct and widespread ecological harm. Preliminary findings from trial mining operations conducted by the Geological Survey of Japan suggest the impacts may be more severe and longer-lasting than initially anticipated, posing serious risks to ocean biodiversity and ecosystem health.

Currently, deep-sea mining falls under existing global frameworks, most notably the United Nations Convention on the Law of the Sea (UNCLOS). These provide a platform for regulating, restricting, or even prohibiting deep-sea mining activities, as well as for pursuing legal action in cases of non-compliance with international law. 

Particularly important is the BBNJ Agreement, which was adopted by UN members in June 2023 and is awaiting ratification. It expanded the international legal tools available to govern marine biodiversity in areas beyond national jurisdiction. 

The International Seabed Authority (ISA), a UN agency set up in 1994, is responsible for protecting the seabed in international waters against ‘harmful effects that may arise from deep-seabed-related activities.’

Deep sea-mining also impacts broader agreements that it could undermine through damage to the ocean, such as the 2022 Kunming-Montreal Biodiversity Framework, under which all countries agreed to protect 30 per cent of coastal and marine areas by 2030. 

Moratorium needed 

Given the ecological risks, political momentum against deep-sea mining is growing. So far, 37 countries (including the UK and France) have declared their support for either an outright ban, a precautionary pause, or a moratorium – a legally binding pause on deep-sea mining that would be ratified by a UN resolution. This position is shared by numerous environmental organizations, scientists and civil society groups globally.

The UN Ocean Conference in France opened with President Emmanuel Macron calling for an international moratorium on deep-sea mining and multilateralism to protect the oceans. His call is in line with his previous support for the SOS for the Ocean Manifesto, but the conference offers a significant platform to crystallize opposition against deep-sea mining.

There are strong reasons to establish a moratorium: First, we currently lack a comprehensive scientific understanding of deep-sea ecosystems and the irreversible harm mining may cause; second, there is a current absence of robust regulatory and monitoring mechanisms; and third, we have not fully assessed the long-term environmental, social and even geopolitical risks of deep-sea mining.

This is an issue where strong engagement from the global scientific community is essential to inform evidence-based decision-making. However, it remains to be seen how much traction the call for a moratorium on deep-sea mining will get within the conference process, which has an extensive list of issues to deal with as it seeks to deliver a transformative ocean agenda for the next five years. 

It is also notable that the US is not participating in the UN Ocean Conference. The Trump administration previously rejected the UN’s SDGs as ‘inconsistent with US sovereignty.’ Any multilateral outcome will therefore likely not include Washington. 

Multilateral solutions 

Without coordinated global action, unilateral actions could irreparably damage fragile marine ecosystems and undermine international ocean governance. The ISA has a critical role in advancing a moratorium, for example by halting the approval of exploitation licenses until robust environmental safeguards and scientific assessments are in place.

Multilateral commitments and coordinated implementation are urgently needed to safeguard the planet’s most vital and vulnerable ecosystems.

Some commentators have called for the ISA to rapidly develop regulations and permit processes for seabed mining. They argue that in the absence of a framework (or in the event of a ban or moratorium), states and companies will proceed regardless, with an even worse impact. 

However, such arguments miss the point. Developing effective international regulations requires time, rigorous scientific assessments, and inclusive, deliberative processes. The push by the Trump administration and other actors to unilaterally grant mining permissions risks undermining these principles. 

The international community must resist this pressure and uphold transparent existing processes that ensure good governance and safeguard the long-term health of ocean ecosystems. Rather than states taking potentially damaging unilateral action, multilateral commitments and coordinated implementation are urgently needed to safeguard the planet’s most vital and vulnerable ecosystems.