As the global demand for critical minerals continues to increase, governments worldwide are continually looking for innovative ways to access these resources, which has led many to discuss the potential for deep-sea mining. However, concerns over environmental damage related to deep-sea operations have prevented greater exploration until now, and recent evidence showing the devastating impact mining could have on marine life could put it on indefinite hold.
A study published in December, funded by The Metals Company, which was hoping to become the first firm to carry out commercial seabed mining, showed the damage that mining operations might have on undersea life. Researchers from London’s Natural History Museum analysed samples from the seafloor before and after conducting a mining test. The researchers found that the number of worms, minute crustaceans, and other small animals in the path of the mining vehicle decreased by 37 percent, while the variety of the creatures also fell by 32 percent.
The test was conducted 4,000 metres under the sea in the Clarion-Clipperton Zone, an area in the Pacific Ocean between Hawaii and Mexico. The area is known for having potato-sized nodules that contain nickel, cobalt, copper, and manganese, which have made it attractive to prospective mining companies.
The Metals Company has invested $250 million in environmental studies to better understand the impact of seabed mining. Dozens of researchers were involved in the project, which will form the basis of the environmental impact statement that is required by regulators for potential permitting. They were permitted to independently analyse and publish their results. The UN International Seabed Authority has not yet approved commercial mining, but it has issued 31 licences for exploration.
Seabed mining uses an autonomous vehicle to collect mineral-rich nodules from the seabed before they are transferred to a ship for processing. The Metals Company hopes to gain approval to mine 1.5 million tons of nodules during its first year of commercial operation. The firm was not concerned about the findings from the recent study, as the 37 percent reduction seen in the analysis was lower than anticipated, and the populations are expected to return over time. The Metals Company also plans to leave around 10 percent of nodules behind when mining.
Scientists had previously assumed that there was little life in the depths of the sea due to its extreme conditions and lack of nutrients. However, greater research in recent years has proven otherwise. The study published in December found 788 species of macrofauna in the Clarion-Clipperton Zone. “We’ve actually only sampled such a tiny proportion of the deep sea,” said the lead author of the study, Eva Stewart. There could be thousands of species waiting to be discovered, “we just haven’t seen them yet,” she added.
The excess sediment released by The Metals Company during its test was also found to dilute the food supply of the zooplankton and small squid. There are concerns that these types of operations could eventually starve the food web. Upon this discovery, the company said it could adapt commercial operating plans to release unused material 800 metres deep to avoid the abundant zooplankton areas. The firm will also reduce the quantity of waste, as it found that some of the slurry left behind contained valuable nodule fragments.
Patrick Schröder, a senior research fellow at the Environment and Society Centre at think tank Chatham House, said, “I think the study shows that current technologies for harvesting are too damaging to permit large-scale commercial exploration… These were only tests, and the impact was significant. If they did that at large scale, it would be even more damaging.”
Another study, assessing a 44-year-old deep-sea mining test site, showed that biodiversity losses from mining operations can have a knock-on effect for decades. Roughly 30 percent of the small animals living on the seabed rely on the mineral-rich nodules to survive.
However, many still view deep-sea mining as too valuable an opportunity to pass up. At present, 37 countries have backed a temporary ban on seabed mining. Norway also recently postponed mining plans in its waters, including in the Arctic region. However, in April, U.S. President Donald Trump announced plans to fast-track domestic and international mining projects, in a bid to secure the country’s critical mineral supply chain.
In an executive order, Trump stated, “Vast offshore seabed areas hold critical minerals and energy resources. These resources are key to strengthening our economy, securing our energy future, and reducing dependence on foreign suppliers for critical minerals. The United States also controls seabed mineral resources in one of the largest ocean areas of the world. Our Nation can, through the exercise of existing authorities and by establishing international partnerships, access potentially vast resources in seabed polymetallic nodules.”
While the new findings may be enough to deter some countries from pursuing deep-sea mining, others will continue to back seabed projects that they see as vital to providing a stable supply of critical minerals. The issue is dividing opinion, as scientists and environmentalists worldwide show increased concern over the potentially devastating impact of mining operations on marine life.
By Felicity Bradstock for Oilprice.com