Despite continued negotiations in 2024, the regulatory framework meant to govern commercial-scale deep-sea mining is still years from being finalized by members of the International Seabed Authority (ISA), the United Nations-affiliated body tasked with governing the mineral resources of the ocean floor in international waters. And because of a legal loophole in the United Nations Convention on the Law of the Sea, it is possible that the ISA could provisionally approve a submitted mining application even in the absence of regulations. This might cause irreversible damage to the seabed and threaten both the greater marine ecosystem and Earth’s vital systems.
Although the ISA has been negotiating the framework for a number of years, numerous gaps in the regulations remain, including many documented in a study that The Pew Charitable Trusts co-authored in Marine Policy in 2024. These gaps include fundamental issues, such as lack of agreement on environmental baseline data requirements; what constitutes permissible environmental harm; compliance, monitoring and enforcement mechanisms; how to address underwater cultural heritage; and insurance and liability requirements.
The negotiators also have not yet considered a significant number of subsidiary instruments, or complementary rules, that are required to accompany the main regulations and would govern important topics such as environmental impact assessments, emergency response and contingency plans, and toxic substances.
One particularly troubling gap is the lack of agreed-upon limits on hazardous mining impacts, which include sediment plumes, noise and light pollution. For example, mining equipment on the seafloor may generate clouds of debris, and as mined material is pumped to the surface and metals and minerals are filtered out, the unwanted sediment and waste are expected to be dumped back into the ocean. These plumes could travel thousands of kilometers from the mining site and have potentially devastating effects on deep-sea ecosystems. Among the potential hazards of plumes is the spread of toxic chemicals, polluting large swaths of ocean at the seabed and throughout the water column. Failing to set standards and limits for the kinds of sediments and waste that can be permissibly returned to the ocean, and when and at what depth this disposal is allowed to occur, is a fundamental gap in the environmental management regime for seabed mining.
Similarly, lack of noise restrictions could harm deep-sea species and wider ocean ecosystems. Recent research supported by Pew and published in July 2022 in Science found that a single deep-sea mining operation could produce noise extending hundreds of kilometers, dramatically increasing the environmental footprint of mining—and potentially affecting the ability of marine creatures to use sound to navigate, communicate, find mating partners, locate food, and detect predators and other dangers.
A small ISA working group has only recently started to develop thresholds to limit levels of toxicity, turbidity and settling of resuspended sediments, as well as underwater noise and light pollution. However, limits for other impacts of mining, such as habitat removal, have yet to be considered.
Deep-sea mining companies are not the only parties with an interest in the seabed. But there is no mechanism in place to foster coordination between mining companies and other users of the seabed, such as the owners of undersea internet cables. That means there is currently no clear path for other stakeholders, including industries that operate in the same areas, to raise concerns about proposed mining plans—and no clarity on what recourse they would have if their concerns are not addressed. Similarly, there is no framework for how these stakeholders could participate in the ISA’s decision making around environmental planning.
Deep-sea mining could have consequences beyond destroying and polluting habitat for marine life. Given the likely vast spatial and temporal scales of its detrimental impacts, there is potential for substantial effects on carbon storage and carbon cycling in the deep ocean, as well as on other ecosystem services, such as vital fisheries.
An increasing number of governments, scientists, and organizations are raising concerns about the potential harm that deep-sea mining would cause and are urging caution. During the ISA’s meetings in summer 2024, five more countries committed to a precautionary pause or moratorium on large-scale, commercial deep-sea mining, bringing to 32 the number of countries that agreed with this position in the past two years.
There are also companies that favor a moratorium on seabed mining. For example, automakers such as BMW and Rivian have said they will not use materials harvested from the deep sea to create batteries for electric vehicles—one of the main uses promoted by prospective miners. Tech companies, such as Apple and Google, also support a moratorium. And more and more investors, insurers and re-insurers have expressed significant concerns about deep-sea mining, threatening the industry’s viability. That includes Deutsche Bank, which, in September 2024, updated its ocean-related policies and joined 15 other financial institutions in saying it will not directly finance deep-sea mining projects.
The ISA’s last negotiating session ended in August 2024, and debate is slated to resume in March 2025. With so many gaps in the regulatory framework remaining, it is difficult to see a path toward completing these negotiations anytime soon.
As many questions remain, it would be irresponsible to allow a commercial deep-sea mining application to move forward. It is imperative that member countries at the ISA heed these concerns and establish a precautionary pause or moratorium on seabed mining before one of Earth’s most pristine and fragile ecosystems is opened to a new extractive industry clouded by uncertainty.
Julian Jackson leads the seabed mining work for The Pew Charitable Trusts’ ocean governance project.
This piece was first published in Sea Technology on Jan. 15, 2025.