Shrimp, yeti crabs, and vent mussels gathered together atop hydrothermal vents. Credit: NOAA Vents Program

By Olivia Grubisich


Just below the ocean’s surface, water glows in sunlight’s embrace. Diving deeper, the seafloor slopes, a chill replacing the residual warmth of the sun. Fading from cerulean to navy, the surrounding water thickens as the ocean presses heavily from above. Farther down still, the last remnants of blue vanish and suddenly, yet without grandeur, darkness extends in all directions.  Despite the darkness, life exists. At mid-ocean ridges, jagged spires rise against the seascape. Plumes of “smoke” billow from these peaks — in some places thick and dark, in others wispy like white clouds. Along the exterior, yeti crabs scuttle between clusters of tubeworms and deep-sea mussels that cover the rock.  

This unique scenery indicates the presence of our ocean’s most ancient topography: hydrothermal vents. At these vents, cold seawater seeps through crevices in the ocean floor, where magma heats it at the Earth’s center. It re-emerges, providing a tricky sort of chemistry that sustains vibrant communities of life at the bottom of the ocean. Discovered less than 50 years ago, hydrothermal vents revolutionized our understanding of the deep sea and the origins of life on Earth. But now these rare, precious deep-sea environments face threats of destruction from mining companies lurking miles above.  

Called the “Candelabra,” this black smoker sits at a depth of 3,300 meters as a part of the Logatchev Hydrothermal Vent Field on the Mid-Atlantic Ridge. Credit: MARUM Research Facility, University of Bremen

Not long after their discovery, scientists realized hydrothermal vents were full of valuable metals. With this knowledge the vents quickly went from being a new natural wonder to a potential source of materials and profit. Mining companies over the last four decades have explored extracting those minerals from the ocean floor. Now, as society pushes for clean energy and more efficient and sustainable technology built with these metals, they are more eager than ever so eager, they’re willing to begin mining without sufficient research or proper regulations. 

The International Seabed Authority (ISA), a U.N. body that governs the business of the sea, met this past summer to solidify regulations for deep-sea mining exploitation. The meeting marked a new phase in a global industry, but even as Pacific island nations and corporations push to mine for undersea minerals, the ISA failed to finalize its rules. That hesitancy, and conflict among ISA members, represents a question that’s been lingering for decades: Do the benefits of underwater mineral extraction outweigh the environmental costs? 

The discovery of hydrothermal vents in 1977 changed the way scientists think about life on Earth. Until this point, consensus said sunlight was a necessary ingredient for survival. It shouldn’t have been possible for so many organisms to live at the vents, thousands of meters below the sun’s reach. The key, it turns out, comes from the vents themselves. On its journey back from the center of the Earth, the water releases metal and other inorganic materials into the surrounding area. Special microorganisms interact with the elements, creating energy in a process called “chemosynthesis.” The micro-organisms survive and feed other creatures, fostering life at the vents.  

Minerals not used up in chemosynthesis continue on a different path, one that lands them in the crosshairs of deep-sea mining. As the hot jets emerge from the seafloor, icy water turns the metals to solids, creating the spindly towers characteristic of hydrothermal vents. Alongside the chimneys, large collections of metals settle on the ocean floor, forming Seafloor Massive Sulfide (SMS) deposits.  SMS deposits are full of metals such as iron, zinc, copper, lead, and sometimes other materials like gold, silver, arsenic, cobalt, molybdenum, calcium, and platinum. 

While much remains unknown about hydrothermal vents and chemosynthesis, it’s clear their unique features play a role in the ocean’s viability far beyond the seafloor. Hydrothermal plumes rise hundreds of meters, distributing microorganisms throughout the ocean to interact with other systems. Additionally, vents are large sources of oceanic iron and manganese, two metals essential to the function of organisms like phytoplankton. And phytoplankton play a large role in undersea food webs, acting as primary food sources for a host of different creatures from micro-organisms to blue whales and a plethora of fish in between. 

Feasibility studies of mining SMS deposits began as early as the 1980s, although low demand for metal at the time made this work mostly theoretical. The growing reliance on technology in our ever-modernizing world has returned SMS mining to relevance. SMS deposits contain metals used in green technologies like electric vehicle batteries, solar panels, and windmill magnets. High concentrations of valuable metals make SMS deposits too alluring for mining companies to ignore, but altering the flow of minerals from vents could be catastrophic for ocean systems. 

There are several ways mining disrupts ocean life. The sounds of equipment, harsh and alien to the creatures of the sea, reverberate far out into open waters. Deep in the ocean, sound plays a role in how organisms communicate, navigate, and detect prey. The scraping and grinding of metal on rock disturbs all these processes, leaving deep-sea creatures without use of functions they need to survive. Mining additionally hinders visual processes. Bright lights on survey equipment slice through the darkness, harming the sensitive eyes of deep-sea organisms created to live without light. Artificial light also interferes with bioluminescence, which is the only natural source of light at such depths.  

Perhaps worst of all, the grinding tools and movement of collector vehicles create sediment clouds. Toxic particles like reduced metals and organic matter stirred up by the machines deplete oxygen from the surrounding area. As clouds resettle, their altered composition interferes with chemosynthesis occurring at the vents.  

Even with those environmental consequences, the deep-sea mining industry is pushing ISA to take a stance. Formed in 1994, the ISA is made up of three separate bodies — the Assembly, Council, and Secretariat — that work together to make decisions about the parts of seafloor that lie outside any country’s individual jurisdiction. Its primary function, according to ISA Secretary General Michael Lodge, is to regulate exploration for and exploitation of deep seabed minerals found in “the Area,” which makes up just over 50% of the ocean seabed.  

Mining industries set their sights on three main types of deep-sea mining: cobalt found in ferromanganese crusts, seafloor sulfide deposits at hydrothermal vents, and polymetallic nodules. Credit: U.S. Governmental Accountability Office

Mining groups “explore” survey areas they’re interested in mining and “exploit” by actually removing metals from the seafloor. The ISA has had exploration regulations in place for years, and so far it’s approved 28 exploration contracts in the Pacific, Indian, and Atlantic Oceans covering more than 1.3 million square kilometers of ocean floor. Poland applied for the 29th contract in January 2017. With so much exploration under way, the desire to exploit grows. Yet despite discussions on exploitation rules dating back to 2014, the ISA still hasn’t come to a resolution. Now it faces a deadline to reach consensus, set in motion by an unlikely source.  

In 2021, the small Pacific island Nauru announced its intention to begin deep-sea mining, invoking a clause in the U.N.’s Law of the Sea called the “two-year rule” that gave the ISA an ultimatum: Mandate regulations by July 2023, or begin accepting mining applications anyway. A reasonably small player on the global stage, Nauru raised the stakes in a last-ditch effort to save itself. One of the wealthiest countries per capita just 40 years ago, Nauru now faces rising poverty from the effects of climate change and a dwindling supply of phosphate, its main export. Deep-sea mining could be an economic lifeline. 

At the ISA meetings that began in March 2023, Nauru stood firm in its desire to mine as soon as possible, gaining support from fellow ISA member China. However, many other member states expressed doubt about exploitation, instead voicing support for precautionary pauses. The Dominican Republic went so far as to formally request mining delays. 

“When in doubt, favor nature,” Edward Anibal Pérez, the Dominican representative, said at the closing meeting. Deep-sea mining is not the only alternative to meet the growing demand for minerals vital to new energy sources, he said. “It is clear there are doubts as to the effects that this activity might cause.” 

Meetings resumed in July, giving the ISA one last chance to put together a unified message. But after two weeks of discussion, progress came to a standstill. With 22 total member states holding anti-deep sea mining positions and others pushing for action, the ISA decided it still needed more time. 

In a news release, ISA officials lauded the progress made toward drafting regulations, but admitted that official regulations won’t be put in place until 2025 at the earliest. It’s simultaneously a victory and a dilemma. Delaying regulations could ensure more thorough protections given to hydrothermal vents and their environments. At the same time, the two-year rule deadline passed on July 9, 2023, meaning the ISA must accept exploitation applications. Although none has been submitted yet, Nauru remains eager to begin mining as soon as possible.  

Deep-sea mining has boomed over the last few years, but decades ago Canadian company Nautilus Minerals hoped to be the first to successfully mine the deep sea. It began exploring waters near Papua New Guinea in 1997, and gave an Environmental Impact Assessment to the Papua New Guinea Government in 2008, seeking approval for its project called “Solwara 1.”  

From the start, Solwara 1 created problems for both local and global communities. The information Nautilus made available to the public about the project failed to satisfy international standards for Free Prior Informed Consent, which are designed to provide indigenous peoples with information about how global endeavors could affect their communities. Without access to this information, people near and far were unsure what to expect once mining began. Unfortunately for locals, it didn’t take long to see how deep-sea mining could impact their livelihoods, culture, and traditions.   

In an ancient practice of shark-calling, men of the native people in Papua New Guinea and New Ireland prepare for a shark hunt weeks ahead, fasting and limiting contact with the rest of their village. Donning traditional attire, they venture out to sea and begin to sing, calling the sharks to them. Catching them with bare hands, the hunters usually return to shore with one or two sharks to feed their village. But mining disrupts all marine life. Unnatural sounds and sediment disorient sharks and drive them away, far from the song of the shark callers. 

“We can call sharks to our canoes,” Jonathan Mesulam, a shark caller from the New Ireland Province, testified at a Mining Watch Canada Conference. “They are a major source of food for our people. When Nautilus started its exploration activities the sharks left our waters.”  

The impact on native peoples, their culture, and legacies may not be enough to spark outrage on its own, but concern over deep-sea mining stretches far beyond Papua New Guinea. Mining practices threaten other marine species, have the potential to cause earthquakes, and could create challenges we aren’t yet aware of. Scientists across the globe argue deep-sea mining violates the “precautionary principle” — what you don’t understand, you probably shouldn’t mess with. Hydrothermal vents are still considered a new discovery. Without further study, there’s no way to know the long-term consequences of deep-sea mining. The precautionary principle, and marine scientists like Beth Orcutt, say this fact alone should be enough to shut down the entire enterprise until scientists have more information.   

“It is difficult to even convey the immense scale of our knowledge gaps.” Orcutt explains in an article for Nature. “Deep-sea corals — like trees on land — are keystone species in their habitats, providing crucial structure for other forms of life. Scientists don’t really know how these corals reproduce: Spawning has never been documented. How can we restore a baseline that we have never observed? We need research covering at least 10 years for each habitat to be able to make evidence-based decisions.” 

Nautilus continued exploring but started having financial issues before Solwara 1’s completion. The project went bankrupt in 2019 and an Australian company called Deep Sea Mining Finance acquired all of the rights, interests, subsidiaries, and intellectual properties of Solwara 1. Its mission was simple: See the project through to completion. According to the Deep Sea Mining Finance website, it is currently working to send production support vehicles to the seabed sites. Eager to move forward, the company continues walking the trail Nautilus paved despite countless warning signs saying to go back. Now, it seems the lid to Pandora’s box is likely to come off.   

Against the background of the ISA’s meetings, the global Deep Sea Mining Summit took place in May 2023, uniting big names and advocates in the deep-sea mining industry. The industry stands on a precipice, yet in the aftermath of the conference there was very little coverage from mainstream media sources about what transpired during the three days of seminars and lectures in London. The only part of the summit flashy enough to garner media attention was a surprise appearance by the villainous trio of Thanos, Dr. Evil, and Darth Vader. During one session, Darth Vader paraded onstage as part of a Greenpeace protest saying, “I’m delighted to be here and learn more about deep-sea mining, because together we can destroy the oceans.” 

Much of the conference focused on manganese nodule extraction, a type of deep-sea mining that supporters argue is less invasive than traditional mining operations, but the same technology and government regulations apply. Summit discussion topics focused on technological advancements and economic opportunities on the horizon. Most eye-catching on the conference website, nestled nonchalantly between guest speaker head shots and flashy popup ads, were the six key topics of 2023. Naively optimistic, or just plain ironic, one stated the conference’s commitment to “Achieving sustainable seabed mining projects in harmony with nature.”  

Images of large, concrete ships plaster the homepages of corporations attending the Deep Sea Mining Summit. Their mining boats sit in the middle of otherwise unimpeded blue horizons, as out of place as suburban roads across a watershed. Website galleries show other pictures of robotic expeditions that successfully reached their arms into the sea, a preview of mining ventures to come. Metal on calm water and harsh lights illuminating normally dark places — these pictures certainly don’t bring harmony to mind.   

And yet, the world needs metal. As impacts of climate change continue to unfold before the planet’s eyes, many scientists believe a technological revolution is the key to saving our planet. In defense of mining, advocates argue metals from the deep sea are not only profitable, but a necessary step in clean energy’s war on climate change. 

 “Expected metal shortages will derail the energy transition,” said Metals Company CEO Gerard Barron in an article for the online publication Mongabay. We owe it to the planet and people living on it, to stay calm, consider all potential sources of metal supply and compare the lifecycle impacts of our options on a project-by-project basis.”  

To repair the damage done by our industrial footprint on the Earth, deep-sea mining calls for the human hand to reach farther than it ever has, once again taking what it does not own.  Barely 50 years since they first appeared on the human radar, hydrothermal vents have revolutionized the way we look at life, and our energy future. The ghost white crabs and bustling microorganisms represent the sometimes-unimaginable truth: No matter how much knowledge we think we have, our world remains full of mysteries. Even in the face of this poignant reminder, we’re still willing to justify destroying what’s left of Earth’s beauty. The ISA decisions are put on hold for now, but with both Nauru and Solwara 1 waiting in the wings to begin mining as soon as possible, there may be little else we can do but watch nature’s oldest frontier disappear before our eyes.

The distribution of hydrothermal vents along the world’s mid-ocean ridges. Credit: DeDuijn via Wikimedia Commons

About the Author …

Olivia Grubisich is a two-time U of I graduate from New Lenox, Ill. She completed her M.S. in Journalism in August 2023, and before that earned her B.S. in Chemistry. She now works as a Communications Specialist with the Department of Civil and Environmental Engineering at the U of I.

This article was written for ESE/ENGL 498, the CEW capstone course.