Deep-Sea Mining's Lasting Impact

Deep-Sea Mining's Lasting Impact: A Half-Century After the First Test, Recovery Is Still Out of Reach

Fifty years after the world’s first deep-sea mining test, the scars left behind on the ocean floor are still visible — a stark warning for what large-scale commercial mining could do to fragile marine ecosystems.

In 1970, US-based Deepsea Ventures conducted a pilot project on the Blake Plateau, a deep-sea region off the coast of North Carolina. Using a vacuum-like machine, the company collected around 60,000 mineral-rich nodules — potato-sized rocks rich in manganese, nickel, and cobalt, which are crucial for manufacturing batteries, electronics, and advanced technologies.

The experiment was short-lived, but its environmental consequences have endured. In 2022, researchers revisited the site using a remote-controlled submersible and found extensive damage: clear dredge lines stretching over 43 kilometers (27 miles) across the seafloor. The disturbed areas remain barren — devoid of nodules, marine life, and biodiversity.

Dr. Samantha Joye, a microbiologist who explored the Blake Plateau in 2018, described the undisturbed parts of the area as teeming with life — home to worms, sponges, sea stars, mussels, and an array of bioluminescent creatures. But where the old mining tracks lie, there is silence. No squid darting by, no shimmering jellyfish, just empty, scarred mud.

“This site serves as a proxy for what could happen elsewhere if we rush into deep-sea mining,” says Joye.

Lessons from the Pacific

A similar experiment conducted in the Clarion-Clipperton Zone — a vast abyssal plain in the Pacific Ocean between Hawaii and Mexico — showed comparable long-term impacts. When scientists ploughed through the seafloor there in 1989, they created disturbances that, even 26 years later, had not recovered. Large animal populations, especially filter feeders, remained sparse, and microbial communities were only partially restored.

"Microbes are some of the fastest-recovering organisms," Joye points out. "If even they haven’t fully bounced back after decades, imagine the impact on larger, slower-growing species."

Research published in March 2025 reinforced these findings, indicating that while some recolonization has occurred, full recovery of these deep-sea habitats may take centuries — if it happens at all.

Push for Commercial Mining Continues

Despite the ecological risks, interest in deep-sea mining remains high. In April 2025, former U.S. President Donald Trump signed an executive order to accelerate domestic deep-sea mining operations. Companies like *The Metals Company* and *Impossible Metals* are positioning themselves at the forefront of this emerging industry, claiming their new technologies are more precise and environmentally responsible than past methods.

Impossible Metals, for instance, touts a “gentle” approach that involves collecting individual nodules without disturbing the seabed. The company has already applied for exploration rights near American Samoa.

However, critics argue that even the most advanced technologies cannot eliminate the fundamental disruption caused by removing resources from such sensitive and poorly understood environments.

A Delicate Balance

As nations weigh the economic benefits of accessing rare minerals against the irreversible harm to deep-sea ecosystems, the Blake Plateau stands as a sobering reminder: once damaged, these ecosystems may never return to their former state.

“We’re talking about places that have existed undisturbed for millennia,” Joye says. “And we’re now considering industrializing them before we even understand what we stand to lose.”

With global demand for critical minerals rising, the debate over deep-sea mining will only intensify. But one thing is clear — the ocean’s depths are not as resilient as they seem.

Deep-Sea Mining: Innovation vs. Irreversible Environmental Risk

“All mining has impacts. But we’ve invented new technology to minimize them,” says Oliver Gunasekara, CEO of Impossible Metals, a company positioning itself at the forefront of next-generation deep-sea mining. He argues that modern techniques — such as precision nodule collection and automated systems — are far less invasive than past methods.

Gunasekara also points to environmental impact assessments (EIAs) as standard safeguards in any mining approval process. These evaluations, he says, help determine whether the ecological costs are “acceptable” before operations begin.

Yet many scientists remain deeply concerned. The deep sea is one of Earth’s least explored frontiers, with over 70% of the ocean floor still unmapped, unobserved, and unexplored, according to Christopher Robbins, associate director of Ocean Conservancy. This lack of knowledge makes predicting the consequences of industrial activity extremely challenging.

Hidden Biodiversity at Risk

In 2023, researchers exploring the Clarion-Clipperton Zone (CCZ), a deep-sea region between Hawaii and Mexico, found more than 5,000 species — around 90% of which were previously unknown to science. The CCZ is now considered a prime target for commercial mining due to its vast deposits of manganese, nickel, and cobalt — metals essential for electric vehicle batteries and renewable energy infrastructure.

The discovery of this biodiversity hotspot underscores how little is known about these ecosystems — and what could be lost if mining proceeds without caution.

Even closer to home, scientists in 2024 uncovered the world's largest known deep-sea coral reef system on the Blake Plateau off the southeastern U.S. coast. Stretching over 500 kilometers (310 miles) from South Carolina to Florida, the reef includes more than 83,000 coral mounds. The find highlights the ecological richness of a region already scarred by the world’s first deep-sea mining test in 1970 — scars that have yet to heal.

Threats Beyond the Seafloor

The environmental risks of deep-sea mining extend far beyond the abyssal plains. As machines scrape the seafloor or vacuum up mineral nodules, they release sediment plumes — clouds of fine particles that can drift hundreds of kilometers through the water column. These plumes may disrupt marine life in midwater zones, where organisms rely on clear, stable conditions to feed, reproduce, and communicate.

Studies show that suspended sediments can interfere with bioluminescent signaling, clog fish gills, and even alter jellyfish mucus production — all critical functions for survival in the deep.

Moreover, these disruptions could affect the ocean’s role in climate regulation. Midwater organisms contribute significantly to carbon sequestration, pulling an estimated six gigatons of carbon out of the atmosphere annually — roughly 14% of global human emissions. If mining plumes impair their ability to function, it could weaken one of Earth’s most vital natural climate solutions.

According to Planet Tracker, deep-sea mining could also release more than 172 tonnes of stored carbon per square kilometer mined each year, further complicating the climate calculus.

Economic Conflicts and Fishing Concerns

Beyond the environmental stakes, there are growing concerns about economic fallout — particularly for the fishing industry. A recent report by Ocean Conservancy warns that deep-sea mining could create conflicts in both the Atlantic and Pacific Oceans, as sediment plumes drift into key fishing grounds.

On the U.S. West Coast, research from 2023 indicates that migration routes of commercially valuable tuna species — including bigeye, skipjack, and yellowfin — could intersect with mining zones. In small island nations, where tuna fisheries support food security and livelihoods, studies suggest up to 10% of catches come from areas potentially affected by seabed mining.

Christopher Robbins emphasizes the need for transparency and long-term planning: “There are just too many unanswered questions that require us to take a step back to allow the fishing industry, frankly, to be better informed about the trade-offs.”

Regulatory Gaps and Uncertain Futures

Despite the ecological and economic stakes, the regulatory framework for deep-sea mining remains incomplete. While the Blake Plateau currently isn’t targeted for mining, experts like Gorka Sancho, a fish ecology expert at the College of Charleston, warn that could change quickly. Sancho co-authored a 2024 letter urging President Biden to establish strong protections for the plateau, citing its ecological value and vulnerability.

Meanwhile, the Clarion-Clipperton Zone remains the focal point for commercial interests. Studies estimate the area holds more nickel, cobalt, and manganese than all known terrestrial reserves combined — making it a tempting target for companies eager to meet rising demand for clean energy technologies.

But as Gunasekara himself acknowledges, “All mining has impacts.” And in the deep sea — an environment that has remained largely untouched for millennia — those impacts could be irreversible.

“We’re talking about places we barely understand,” says Robbins. “Before we rush to industrialize them, we must ask: What are we willing to lose?”

**Fast-Tracking Deep-Sea Mining: Conflicts, Concerns, and the Need for Caution**

In April 2025, former U.S. President Donald Trump signed an executive order titled *Unleashing America's Offshore Critical Minerals and Resources*, aimed at accelerating deep-sea mining operations in U.S. waters. Days later, the Canadian firm **The Metals Company** submitted a request to the U.S. government for licenses to explore and mine seabed resources — including areas beyond U.S. jurisdiction.

This move has raised legal concerns. According to Leticia Reis de Carvalho, Secretary-General of the International Seabed Authority (ISA), granting such permits could conflict with the **United Nations Convention on the Law of the Sea (UNCLOS)**, the international treaty that governs the use of the world’s oceans and seafloor. However, it’s important to note that the United States has never ratified UNCLOS, which may influence how it interprets its obligations under international maritime law.

NOAA Caught in the Crossfire

Trump’s executive order directs the **National Oceanic and Atmospheric Administration (NOAA)** to expedite environmental assessments and mining permits. This directive has sparked concern among scientists and conservationists, who argue it conflicts with NOAA’s core mission of protecting ocean ecosystems and marine life.

Christopher Robbins of Ocean Conservancy notes, “NOAA is tasked with understanding and preserving the ocean environment. Being asked to fast-track industrial activity without full scientific backing contradicts that mandate.” The BBC reached out to NOAA for comment but received no response before publication.

Scientific Uncertainty and Calls for Better Data

At a congressional hearing reviewing the new policy, MIT mechanical engineering professor **Thomas Peacock**, whose research has been partially funded by The Metals Company, presented findings from his 2022 study on sediment plumes generated by nodule mining.

His team found that only 2–8% of disturbed sediment rises more than 2 meters (6.5 feet) above the seafloor and remains suspended for hours. He described the concentration as "roughly equivalent to a grain of sand in a fishbowl," suggesting that some environmental impacts may be less severe than feared.

However, Peacock also stressed the need for better data collection tools and modeling systems to accurately predict large-scale effects. He emphasized that even with improved technology, certain parts of the ocean must remain off-limits to protect biodiversity and critical habitats.

 Global Moratorium Gaining Momentum

Despite growing industry interest, many nations and experts are urging caution. Over **900 scientists and policy experts** have signed a letter calling for a pause on commercial deep-sea mining until the ecological risks are fully understood and robust regulatory frameworks are in place.

Several countries — including France, Germany, and New Zealand — have already voiced support for a moratorium or strict pause on seabed mining until independent science and global oversight mechanisms can catch up.

A Legacy of Damage and a Call for Stewardship

Meanwhile, the Blake Plateau, site of the **world’s first deep-sea mining test in 1970**, continues to bear visible scars from that experiment. Half a century later, the dredged tracks remain, serving as a stark reminder of the long-lasting impact of human intrusion into fragile deep-sea ecosystems.

Dr. Samantha Joye, a microbiologist who explored the region during a 2018 dive, describes the plateau as a place of extraordinary biodiversity and mystery.

"I see this place as a national treasure. What makes it so special?" she reflects. "That mystery is something we need to solve — so that we can serve as stewards of these habitats."

As governments and companies push forward with deep-sea mining ambitions, the question remains: Can we afford to industrialize the ocean floor before we truly understand what lies beneath?