Life at the bottom of the Pacific Ocean is slow, dark and quiet. Strange creatures are sparkling and sparkling. Oxygen penetrates mysteriously through the rugged metal rocks. These deep ocean inhabitants are rarely interfering with each other.
“There's a strange life here,” said Bethany Orcutt, a geobiologist at the Bigelow Institute for Marine Science.
Given the extreme conditions, deep sea research is extremely difficult and rare given the price tag.
On Thursday, President Trump signed an executive order aimed at allowing industrial mining undersea for the first time for minerals. Scientists have expressed their deep reservation that mining can irreversibly harm these deep-sea ecosystems before the value and work are fully understood.
What's there anyway?
Undersea mining can target three types of metal-rich sediment: nodule, crust, and mounds. But for now, it's all about the nodule. Nodules are especially valuable as they include metals used in the manufacture of electronic equipment, sophisticated weapons, electric vehicle batteries, and other techniques necessary for human development. Nodules are also the easiest undersea mineral deposits to collect.
Economically viable nodules have been formed for millions of years and sit on the seabed forever. Nodules are born when elastic bits of material, such as shark teeth, get caught in the seabed. Minerals containing iron, manganese and other metals accumulate slowly like snowmen. The largest is the size of grapefruit.
Life also accumulates in the nodules. Microbial organisms, invertebrates, corals and sponges all live on the nodule.
Lisa Levin, an oceanographer at the Institute of Oceanography, says that about half of the known life, about half of the vast ocean floors, known as the Abyssal Plains, lives in these nodules. But “I don't know how widespread the species is, or if one area is mined, there are individuals who can recolonise another location,” she said. “That's a big unknown.”
How do you mine the ocean?
Two major approaches to nodular mining have been developed. One is basically a claw, rubbing along the seabed to collect nodules. The other is essentially a vacuum in the ocean industry.
In both, nodules are raised on surface ships several miles above the seabed. The remaining water, rocks and other debris are dropped into the sea.
Both dr and vacuum cleaners are very much intrusive unless they destroy the undersea habitat itself. Removing nodule means removing what scientists think.
Mining activities bring light and noise pollution not only to the seabed but also to the surface of the sea where the ship is located.
The central concern is the sediment plume produced by both the seabed and mining Jeffrey Drazen, an oceanographer at the University of Hawaii at Manoa, described it as “the most clear seawater” at a depth of about 1,000 meters, with “some of the clearest seawater.” Sediment plumes that can travel vast distances can kill lives in unpredictable ways.
The sediment was able to choke shrimp and sponge-like fish and choking filter feeders. It blocks small lights that are contagious to the ocean and prevents lantern fish from finding companions and anglers to invite prey. It can also be stacked with discarded metal to contaminate the seafood that people eat.
“What is the chance of contaminating food supplies?” Dr. Drazen said. Before the mining began, he said, “I really want the answer to that question, and now we don't have it now.”
What do mining companies say?
The mining company says it is developing a sustainable and environmentally friendly deep-sea mining approach through research and involvement with the scientific community.
Their research includes basic research in seabed geology, biology and chemistry, documenting thousands of species and providing valuable deep-sea photos and videos. Dr. Drazen said interest in undersea mining supports research that might otherwise be difficult to fund.
Preliminary testing of recovery equipment has provided some insight into the foreseeable effects of practices like sediment plume, but modelling can only proceed to date in predicting what will happen once mining reaches commercial scale.
Impossible Metals, a California-based undersea mining company, uses artificial intelligence to develop a transport container-sized underwater robot that uses large, living-free nodules. In 2022, Metals Company, a Canadian deep-sea mining company, recovered approximately 3,000 tonnes of nodule from the seabed and collected data on the process plume.
In March, the metals company announced that it would circumvent international submarine authorities, an organization affiliated with the United Nations to regulate submarine mining, seeking permission to submarine mining through NOAA.
In an interview Thursday, the company's CEO, Gerald Baron, said in an interview Thursday that the executive order “is not a shortcut” to past environmental reviews, and that the company has “completed more than a decade of environmental research.”
White House spokesperson Anna Kelly said the US will comply with two American laws that govern deep-sea exploration and commercial activities in US waters. “Both these laws require comprehensive environmental impact assessments and compliance with strong environmental standards,” she said.
What are the long-term risks?
Many scientists remain skeptical that they are well known about the environmental impacts of submarine mines to move forward. They can only hypothesize about long-term outcomes.
Disrupting the bottom of the food chain has a ripple effect on the entire marine environment. The extreme example is when sediments dilute plankton's food supply, Dr. Drazen said. In that case they could have been starving and could not remove enough organic matter from the clouds of sea dust.
Small plankton is a basic food source, either directly or indirectly, for almost every creature in the ocean, up to whales.
Part of the challenge in understanding potential impacts is the slow pace of life on the seabed. Deep sea fish can live for hundreds of years. Corals can live by thousands.
“It's a different time scale in life,” Dr. Levin said. “It supports some unknowns about reactions to disturbances.” It is difficult for humans to perform 500 years of experiments to understand whether such ecosystems can bounce or adapt.
Furthermore, there is no guarantee that it will restore destroyed habitats or reduce damage to the seabed. Unlike mining on the land, “there is no deep-sea strategy,” Dr. Oucht said. “There is currently no scientific evidence that ecosystems can be restored after they are damaged.”
Some scientists have questioned the need for undersea mining, saying that land mines can accommodate increasing demand for metals.
Advocates of deep-sea mining claim that their environment or carbon footprint is smaller than traditional mining of those same minerals.
“There has been no actual recovery of minerals to date,” said Amy Gartman, a marine researcher who leads the U.S. Geological Survey Undersea Minerals Team, referring to commercial-scale mining. “We're comparing theoretical and actual land mining practices. If someone actually breaks the ground in one of these projects, we can get a better idea.”
Eric Lipton and Harry Stevens Reports of contributions.
