Mining the sea floor for precious metals such as zinc and cobalt could lead to ‘irreversible’ damage to marine ecosystems, scientists warn.
Demand for battery powered devices such as electric cars has created a drive to mine the cobalt rich seabed, say researchers from Bigelow Lab for Ocean Sciences.
Experts at the Maine, New England research facility examined the potential impact of disruption from mining to deep sea micro-organisms and the surrounding system.
Microbes on the seafloor are responsible for essential ecosystem services, said Beth Orcutt, a senior researcher at Bigelow, who urged caution from mining companies.
They found that environments that are promising for mining are also often sites of globally important microbial processes and unusual animal communities.
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The Mafuta diamond mining vessel, operated by Debmarine Namibia, searches for diamonds using a ‘crawler’ tractor to suck up sediment from the seabed. More mining operations for other types of minerals are expected to come online in the coming years
Orcutt said these communities are ‘very slow to recover from disturbances’ and so said policy makers should consider the impact when issuing licences.
‘The push for deep-sea mining has really accelerated in the last few years, and it is crucial that policy makers and the industry understand these microbes and the services they provide’.
One of the first companies with a licence to explore the seabed for mining opportunities is Nautilus Minerals.
They plan to use a version of the systems created for offshore oil and gas extraction to remove gold, silver, zinc and copper from the deep ocean.
The European Commission says the quantity of minerals on the ocean floor is ‘potentially large’.
They say any mining on the sea bed should be to ensure security of supply and fill a gap in the market where either recycling isn’t possible or the burden on land minerals is too high.
The commission is working on a range of studies to investigate the impact and potential of seabed mining.
The United Nations has issued 29 licences to explore the deep sea for rare minerals that will go on to be used in electric vehicles and other battery devices.
Some mining operations are already in place. De Beers and the Namibian government have an operation searching for diamonds at sea using a ‘crawler’ tractor to suck up sediment from the seabed in the Atlantic Ocean.
A 2019 Greenpeace report said unless safeguards were put in place there would be ‘severe and irreversible harm’ to the world’s oceans from mining.
‘This greedy industry could destroy wonders of the deep ocean before we even have a chance to study them,’ said Louisa Casson from the campaign group.
Researchers from Bigelow say the impact varies from site to site, with not all locations on the seabed as vulnerable as each other.
Their findings indicate that the likely impacts of mining on microbial ecosystems vary substantially, from minimal disturbance to the irreversible loss of important ecosystem processes.
Hydrothermal vent systems are likely to be the most sensitive as well as the most valuable for mining operations, according to Orcutt and her team.
Tiny crabs, tubeworms, and other sea life live next to a hot hydrothermal vent.These vents contain potentially large amounts of precious metals such as cobalt and zinc
The hot, mineral-rich waters support robust communities of microbes that form the vital base of the food web in these ecosystems, she explained.
‘These microbes have incredible potential to inspire new solutions to all sorts of medical and technical challenges we face today,’ said Julie Huber, a scientist from the Woods Hole Oceanographic Institution and co-author of the new study.
‘But if we damage or destroy a habitat like a hydrothermal vent, we lose the diverse pool of microbial genetic information from which we can find new drugs.’
The International Seabed Authority of the United Nations is working to establish guidelines for countries and contractors to explore the seafloor for minerals.
The heat and minerals expelled by the vent allow these creatures to survive without sunlight. They are important eco-systems that would be irreversibly destroyed if disrupted, say scientists
The team behind the study say that as well as considering how much microbial life is present at a potential mining site, as is currently in the draft guidelines, they should also look at the role microbes are playing and any impact on them from mining.
‘It is important to understand the potential impacts of mining activities to figure out if they should occur and how to manage them if they do,’ said James Bradley, a scientist at Queen Mary University of London and co-author on the paper.
‘This is an important conversation between policy makers, industry, and the scientific community, and it’s important that we work together to get this right.
‘Once these ecosystems are damaged, they may never fully recover.’
Greenpeace have called on governments to create a strong global ocean treaty to protect the underwater environments.
The research has been published in the journal Limnology and Oceanography Reports.
WHAT IS SEABED MINING?
The number of minerals, including precious metals such as gold, zinc and cobalt buried in the seabed could be significant, say the EU.
As demand for electronic technologies such as electric cars and smartphones has increased, the idea of mining the seabed has become more prominent.
It is a complex and expensive process, but will become more lucrative as the supply of minerals from land based sources or recycling reduces.
There is currently a series of ‘explorations’ happening to discover the most valuable sites to mine.
It’s expected the most likely sites are around hydrothermal vents between 4,600ft and 12,100ft below the surface.