Last month, the Bureau of Ocean Energy Management, who oversees seabed mineral mining within US water received an application from Impossible Metals to lease an area offshore of American Samoa for deep-sea mining trials. Unlike The Metals Company’s bid to mine the high seas under US license, the Federal Government had clear authority to issue mining licenses within its own water. The permitting process is now open for public comment and I encourage anyone who feels strongly on this issue to respond to the BOEM RFI, here: Request for Information and Interest: Commercial Leasing for Outer Continental Shelf Minerals Offshore American Samoa
Below it the letter I submitted this morning.
Subject: Deep Sea Mining Leases Off American Samoa (BOEM-2025-0035 RFI Comments)
Dear Bureau of Ocean Energy Management,
I am a US-based deep-sea ecologist and marine technologist who has been working on deep-sea mining in various capacities since 2008. I have conducted primary research on the environmental impacts of deep-sea mining, led the Deep-sea Mining Observer trade journal which tracked the development of the industry, and consulted for companies, NGOs, and international regulatory bodies on issues and opportunities presented by deep-sea mining.
I am writing to encourage a cautious approach to the development of deep-sea mining of polymetallic nodules in US waters off American Samoa as well as to oppose the development of deep-sea mining for seafloor massive sulphides or cobalt rich crusts within US waters. Though all three resources are identified in the President’s Executive Order on Offshore Critical Minerals, the inherent nature of seafloor massive sulphide and cobalt-rich crust mining presents unacceptable risks to the marine environment. Of particular concern is the close proximity of the RFI area to the Rose Atoll Marine National Monument, considered one the the most pristine marine ecosystems left in the world.
While deep-sea mining for polymetallic nodules does have potential for the renewable energy and electric vehicle transition, the pace of development and time-frame for commercialization presents a unique opportunity to develop a next-generation extractive industry in collaboration with ecologic and scientific concerns.
Deep-sea mining of polymetallic nodules has a long shallow tail before it achieves a level of production that competes with terrestrial mining, if indeed, it ever will. The most optimistic estimates by industry-leading deep-sea mining companies predict that within 10 years of commercialization, they would be able to reach approximately 3% of the total worldwide production for cobalt and nickel. Indeed, increasing domestic processing of cobalt and nickel ore, rather than domestic production, would yield vastly greater short term resource gains while increasing control over the critical minerals supply chain. While, long-term, the benefits of deep-sea mining may become tangible, the short-term urgency of the industry is artificial. Deep-sea mining presents a rare opportunity to develop world-leading processes for an emerging extractive industry prior to exploitation.
Humans have explored less than 1% of the seafloor, and every new expedition yields new discoveries, some of which are fundamental to our understanding of biology, ecology, and geology. Discoveries made on the deep sea floor have revolutionized medicine, forensics, materials science and have provided fundamental insights into evolution, genetics, and microbiology. Deep-sea exploration has revealed new biogeochemical processes which support next-generation industries.
There are substantial unknowns regarding the environmental, social, and commercial impact of deep-sea mining. Beginning from the surface, few investigations have been made into how deep-sea mining operations will impact highly migratory species, commercially important fisheries like tuna, and the migration and behavior of marine mammals. Noise, light, sediment discharge plumes, and the attractive effect of stationary vessels acting as fish aggregating devices all can have impacts on animals that live and move through the surface waters where deep-sea mining occurs. In the mid-water, sediment discharge plumes may alter the chemical composition of the water column, disrupting the diel vertical migration of prey species and adversely impact many commercially and culturally important predators. Noise from riser and lift systems can adversely impact marine mammal behavior, as well as sharks, and other migratory species which use sound to locate and communicate. On the seafloor, sediment plumes may smother the immediate area surrounding a mining operation as well as spread for several miles, burying peripheral communities and altering the topography of the seafloor. The deep abyssal plain is a world of slow processes and homogeneous conditions. Polymetallic nodule fields require millions of years to form. Any direct impacts will be, for all intents and purposes, permanent.
These unknowns are not insurmountable. One of the ironies of deep-sea mining is that we know so little about the seafloor that interest from deep-sea mining companies is one of the dominant drivers of deep-sea research. This has, in several cases, led to discoveries which preclude development of that resource. Scientists and deep-sea mining companies have had long and productive partnerships which have led to new and exciting insights into the ecology, biology, and geology of the deep ocean. Newly discovered phenomena like “dark oxygen”, which was discovered via deep-sea mining-funded research, present opportunities for collaboration.
Deep-sea mining of polymetallic nodules is a high-risk, high-reward-venture that is dependent on high demand for critical metals, specifically nickel and cobalt, needed in the electric vehicle industry. While manganese is also provided as part of the value-proposition for deep-sea mining, the manganese produced in even the smallest hypothetical mining operation in the CCZ would nearly double the global manganese supply. While this may be appealing from a critical minerals standpoint, from a commercial standpoint, this means that many of the long-term financial projections for deep-sea mining wildly overestimate the potential profitability of the endeavor based on a static or rising demand for manganese rather than a likely surplus. Cobalt and nickel are also currently enjoying a supply surplus which challenges the financial projections for the industry. Thus, even under a scenario in which commercialization of deep-sea mining happens rapidly with no unforeseen externalities, there is no guarantee of long-term financial success. Fast-tracking of permitting does not necessarily result in fast-tracking of profit.
This is a financially precarious period for deep-sea mining contractors, where the bulk of investment in exploration, environmental compliance, and technology are being made well ahead of any potential profits.
The Bureau of Ocean Energy Management should develop a permitting track for EXPLORATION leases, parallel to the process devised by the International Seabed Authority, which enables mining contractors to identify and assess the value of seabed mineral resources in the lease area and conduct environmental impact assessments. These studies should be conducted in collaboration with researchers from NOAA, USGS, BOEM, and other competent agencies, as well as academia. By promoting partnerships and cost-sharing with federal agencies, an EXPLORATION license can alleviate some of the financial burden placed on the contractors while supporting transparency and scientific discovery. Critically, the issuance of an EXPLORATION lease to better understand mineralogical and environmental value of the region does not confer a guarantee that an EXPLOITATION lease will be issued in the future.
I am writing neither to support nor oppose the development of a permitting regime for deep-sea mining of polymetallic nodules, but to encourage an adaptive approach that incentivizes the industry by promoting stepwise development, beginning with an exploration phase of sufficient length to address many of the known and unknown questions inherent in commercial exploitation of the seafloor. Leases issued exclusively for exploration, rather than exploitation, should not convey a guarantee of future exploitation, but should seek to mitigate some of the financial risk that mining contractors undertake through partnerships and resources sharing arrangements with competent federal agencies.
I am also writing to encourage the comprehensive exclusion of seafloor massive sulphide and cobalt-rich crust seabed mineral resources from consideration for any future mining leases. Seafloor massive sulphides, both active and inactive, host unique chemoautotrophic communities found nowhere else on earth. These deep-sea hydrothermal vents have facilitated among the most important scientific discoveries of the last half century. Unlike polymetallic nodule fields, the total surface area of all known deep-sea hydrothermal vents, globally, could easily fit within the island of Manhattan. Mining of hydrothermal vents is significantly more invasive than mining polymetallic nodules and would result in the comprehensive destruction and complete defaunation of the immediate community. Cobalt-rich crusts occur on seamounts, which host large, biodiverse, and commercially important ecosystems. These ecosystems support nursery and feeding grounds for many commercial fisheries, as well as cold water coral reefs that form an essential foundation to the marine food web. Like hydrothermal vents, cobalt-rich crusts occur in small, discrete areas, rather than across the vast abyssal plain. Mining cobalt-rich crusts is significantly more invasive than mining polymetallic nodules and would result in defaunation of the immediate community and potentially long-term impacts to commercially important fish species.
Thank you for your attention on this matter.
Sincerely,
Dr. Andrew D Thaler
Blackbeard Biologic: Science and Environmental Advisors
