Deep-Sea Mining

What’s at Stake?

Reflections from the 30th Session of the ISA

Our Science Communication Officer, Carly Rospert, had the opportunity to attend Part II of the 30th session of the International Seabed Authority (ISA) Council in Kingston, Jamaica — a pivotal moment in the global conversation about deep-sea mining. The stakes were high, the discussions intense, and the outcome clear: the world is not yet ready to move forward with mining the deep seabed.

Despite the ISA Council President, Ambassador Duncan Muhumuza Laki of Uganda, opening the session with hopes to finalize and adopt mining regulations, consensus proved elusive. And, for the sake of ocean biodiversity and future generations, we think that’s a good thing. Read Carly’s reflections from the session below.

A Crossroads: Protection vs. Exploitation

Almost all ISA member states agree on one thing: regulations are necessary. But the motivations vary — some want to exploit deep-sea minerals, others aim to protect the marine environment from irreversible harm. The heart of the debate lies in how we balance these opposing visions.

Deep-sea mining targets three mineral resources from three different ecosystems:

  • Polymetallic Nodules: Found 4,000–5,000 meters deep on the seafloor, especially in areas like the Clarion Clipperton Zone (CCZ). These nodules support ecosystems where 88-92% of species are new to science and half of those rely on the nodules for survival.
  • Polymetallic Sulfides: Found around hydrothermal vents — rare and unique ecosystems separate from the sunlit food web. Inactive vents (the proposed mining sites) are poorly understood and though may be geologically inactive, research indicates that they are still biologically active and important for ocean productivity.
  • Cobalt-Rich Crusts: Found on seamounts — biodiverse, vital habitats for many species. Seamounts also provide way finding indicators for migratory animals and, due to their high productivity, support fisheries.

Each ecosystem harbors unique, vulnerable life. And in each, the long-term consequences of mining are still unknown.

©
GEOMAR, CC-by-SA-4 and NOAA, CC-by-SA-2
Three targeted minerals in three deep-sea habitats.

Equity and the “Common Heritage of Humankind”

A strong theme across the session was equity. The seabed and its resources are designated as the common heritage of all humankind. But who will actually benefit from mining?

Many delegates from small or low/middle income nations voiced concerns that deep-sea mining could become a new form of resource colonialism — enriching a few, while leaving others with environmental and economic burdens. Key issues raised included:

  • Benefit sharing – how will the potential financial wealth from mining be distributed across member states?
  • Capacity building – how are necessary capacities for mining and research being built in small or low/middle income countries?
  • Technology and knowledge transfer – how are advances in mining technology and knowledge being shared between member states, especially between wealthy and low/middle income countries.
  • Meaningful inclusion and cultivation of diverse expertise – how are scientists from low/middle income countries – especially from the Global South – being meaningfully integrated into the research and knowledge building around the deep-sea and mining?

Additionally, Indigenous voices need a meaningful seat at the table. Cultural heritage and spiritual connections to the deep ocean — especially in the Pacific — are crucial to preserve, yet often underappreciated in negotiations. Past global conventions, which have historically not represented indigenous voices, continue to shape current conversations and leave a legacy of exclusion.

NGO Observers to the ISA are allowed to participate in the session, and occasionally, if called upon, can share statements or questions related to the topic of discussion.

The Science: What We Don’t Know

Science has made progress, but significant knowledge gaps about the deep sea and impacts from mining remain. Consider this:

  • Only 0.001% of the ocean floor has been visually surveyed.
  • The deep sea operates on a different timescale — animals can live for centuries, ecosystems recover slowly (if at all).
  • Many species may go extinct before they’re even discovered.

For each of the three mining mineral targets, scientific uncertainty, especially around impacts and ability to recover, is a major issue:

  • Nodules: In the CCZ, over half of the species, many which are undescribed, depend on nodules. Remove the nodules, and you risk species extinction. Indirect impacts, like sediment plumes, could have far-reaching effects like the significant disruption of ecosystem services.
  • Sulfides: Around inactive vents, we know little about what species live there. What we do know from nearby active vents, is that these are incredibly rare and important ecosystems with many species that only live in these unique habitats. Damaging vents through mining – even inactive ones – could result in the massive loss of entire species.
  • Crusts: On seamounts, mining involves scraping the seafloor – removing the top layers of life-filled and life-supporting crust, thus destroying the incredible biodiversity housed in these habitats. It also would likely impact fisheries and migratory species who indirectly depend on these ecosystems.

Even if restoration were technically possible (and that’s a big “if”), it would likely take centuries, not decades and be very, very difficult.

 

Beyond Biology: The Economics Don’t Add Up

As scientists, most of our concerns focus on ecological risks and scientific knowledge gaps, but the economic case for deep-sea mining is an important topic for everyone at the session. And even here, the case for deep-sea mining seems to fall short.

Key points raised include:

  • Some economic models show a negative net present value — meaning deep-sea mining may not be profitable at all.
  • Metal prices have dropped since original projections – so the expectation of enormous wealth to be gained through mining is becoming less and less realistic.
  • A true cost-benefit analysis must account for environmental damage, social and cultural loss, and long-term legal and financial liabilities, something very difficult to do given current knowledge gaps.

One study assessed different cost-benefit variables and found significant gaps in qualitative knowledge and quantitative data that could be used in a comprehensive analysis. Even with incomplete information, the early indicators are troubling: an economic expert shared that we may be trading $1 in revenue for $9 in long-term social and environmental costs. Begging the question: is deep-sea mining really worth it?

 

Governance: Old Assumptions, New Realities, Added Pressure

When deep-sea mining was first proposed in the 1960’s, the deep sea was thought to be lifeless, and the economic returns limitless. We thought we could mine with very little impact to the ocean ecosystem and it would result in significant financial wealth. We now know these assumptions were wrong — but they still shape today’s debates.

The International Seabed Authority (ISA)was created to govern the seabed that extends beyond national jurisdiction – what is considered to be the common heritage of all humankind. And in this role, was tasked with developing regulations for mining that would ensure that the profits from this exploitation would truly benefit all humankind.

To adopt the mining code regulations, the ISA council must approve by consensus. This ensures broad agreement, but it also means the process is slow. Some states fear that outside pressure — such as the April executive order by the U.S. President Donald Trump to move forward with deep-sea mining unilaterally — could force premature decisions.

While the US’s unilateral action isn’t technically illegal as they are not a member of the ISA (only an observer), any participation by ISA member states in any part of the mining process (including transportation and mineral processing) could breach international law. Many states are rightly cautious, unwilling to make irreversible decisions while major scientific, legal, and ethical questions remain unanswered.

 

So, Where Do We Go From Here?

The session made one thing clear: deep-sea mining is not just a technical issue — it’s a moral and societal one. We must ask ourselves:

  • What level of ecological damage is acceptable?
  • How many species are we willing to lose forever?
  • What do we owe future generations?
  • And ultimately, is mining even worth it?

There’s a critical need to strengthen the science-to-policy interface, define clear environmental goals that can guide further scientific research, and ensure that decisions are informed by independent, transparent research — not just economic ambition that may not even reflect our current reality. This is aligned to Senckenberg Nature Research and Senckenberg Ocean Species Alliance (SOSA)‘s call for a precautionary pause of deep-sea mining in the face of insufficient science.

For now, the world has hit pause. And that might be the wisest decision of all.

A special thanks to the Deep Sea Conservation Coalition for enabling me to attend as part of their cohort through their official ISA observer status.