Video footage from a deep-sea mining test, showing sediment being discharged into the ocean, has raised new questions about the largely untested nature of the industry and the potential damage it could do to ecosystems as companies push for full exploration of the ocean floor all this year.
The Metals Company (TMC), a Canadian mining company that is one of the leading players in the industry, tested its underwater extraction vehicle from September to November last year in the Clarion Clipperton Fracture Zone, a section of the Pacific Ocean between Mexico and Hawaii .
But a group of scientists hired by the company to monitor the activities became concerned about what they saw and posted video of what they believe was a flawed process that accidentally released sediment into the ocean. The scientists also said the company was falling short in its environmental monitoring strategy, according to documents reviewed by the Guardian.
As the push for deep-sea mining increases, experts are increasingly concerned that companies will raise clouds of sediment, which could be laden with toxic heavy metals that could harm marine life. At least 700 scientists – along with France, Germany and Chile – are calling for a moratorium on deep-sea mining.
In a post on its website, TMC acknowledged the incident, but described the cyclone separator discharge as a “minor event” that released “a small amount” of sediment and nodules into the ocean. The company said it fixed the problem in its equipment to prevent further flooding and concluded the incident “did not have the potential to cause serious damage”.
In a statement to the Guardian, the International Seabed Authority (ISA), a UN-affiliated body set up to monitor and regulate deep-sea mining, said its preliminary assessment “has not identified a threat of harm to the environment” but was waiting for a more detailed report of the incident from the company.
While many of the technologies used in deep-sea mining were developed decades ago, the accidental discharge during testing highlights the challenges of tailoring equipment for field use.
Experts and critics warn that the incident highlights the relative uncertainties surrounding deep-sea mining. Companies are scrambling to scour the ocean floor for valuable metals, which are used in electric vehicle batteries and a host of other technologies, such as green energy production, amid a global scramble for a stable supply.
“What we have seen is an unauthorized release and in terrestrial mining it would affect one way or another. And the company says they told the regulator out of courtesy? This is bizarre,” said Catherine Coumans of MiningWatch Canada, adding that the incident goes against companies’ assurances that no sediment will be released near the surface of the ocean.
TMC, based in Vancouver but with senior staff scattered across the US and Europe, says it has explored vast stretches of seafloor to mine “polymetallic nodules” formed from nickel, copper, cobalt and manganese that have been deposited from ocean waters over millions of years. years.
It has long been known that the nodules contain critical elements for the construction of batteries and other electronics, but due to their depth, extracting them was until recently considered too expensive and too heavy.
Heavyweight investors now eagerly eyeing deep-sea mining include Danish logistics giant Maersk and raw materials multinational Glencore, underlining the industry’s hopes for unearthing new sources of critical metals, such as copper, cobalt and nickel.
Investor material from TMC suggests the company believes its Pacific mining sites could generate more than $30bn (£24bn) in profits over the next 20 years with minimal damage to the environment. But the push is becoming increasingly controversial: Two years ago, major battery users, including Google, Samsung, Volvo and BMW, joined a call from the World Wildlife Fund (WWF) for a moratorium on seafloor mining over fears of lasting environmental damage.
Scientists hired by TMC and its subcontractors say the sediment monitoring plan, crucial to the company’s approval to begin mining, was developed without fully considering how sediment plumes (debris that rise from mining on the seafloor) actually form. work, and that those in charge of monitoring efforts had little experience working with the plumes.
In one case, scientists observing the tests claimed that a subcontractor of the project, the DHI company, used a robot to cause disruption after mining operations did not go according to plan. As a result, the scientists called all the data obtained “unverified and unscientific”, and largely useless.
They also said DHI was trying to “influence independent scientific sampling activities” by directing scientists to take samples when no plume was present, and warned that the deficiencies caused a “failed and flawed monitoring operation.” In their notes, the scientists concluded that the data “cannot be considered for any future research and cannot support modeling validation or future modeling efforts.”
Related: Race to the bottom: the disastrous, blindfolded rush to mine the deep sea
DHI told the Guardian that testing parts of the water without sediment, known as “out-of-plume” measurements, is a critical part of the monitoring process to establish the plume’s boundary. Tom Foster, president of DHI Water and Environment, said it was “deeply misleading” to characterize the testing procedure as an attempt to “influence” scientific sampling. The company followed “standard precautions” for assessing potential contamination of samples, he said, and had procedures in place to reject samples “adversely affected by contamination.”
In a statement to the Guardian, TMC said that, as part of its monitoring efforts, samples were taken from various plume concentration levels to better understand the “behavior and impact of the collector system and plume.” The company said it had hired “leading experts in the field” to oversee the monitoring, and dismissed “unfounded” claims of any attempt to manipulate the data.
Critics have long feared that the sediment plumes created by extraction could seriously harm marine ecosystems by limiting light penetration and releasing harmful toxins. “We don’t know what the consequences of those problems were below the surface of the sea,” says Coumans. “We are only seeing the tip of the iceberg. We don’t get transparency.”