Article by Richard Smith, P&S Business Lead.
The debate on Seafloor Mining continues to hit the press, as prototype machines aim to rumble across the seafloor at a depth of 3000 to 4000m harvesting nodules, producing data and recording results to optimise collection system designs. In recent months, a number of heavyweight multinationals, such as BMW and Samsung, have come out against the use of Subsea Mining as a source for the precious metals required for battery and electronics manufacturing, but there are still large amounts of funding being spent by investors and Industry pioneers, such as the Metals Co. and DEME, working on methodologies for the recovery of minerals from such water depths on an industrial scale.
Full scale operations are still subject to suitable international legislation and laws being ratified, and progress is dictated by the International Seabed Authority (ISA) and the 167 Member states, but the clock is ticking.
There is a growing call for further research in the use of Subsea Mining and the potential impact on marine life due to these activities. Even after many years of research and multiple scientific campaigns, the true extent of plume migration and impact on sea-life is still relatively unknown / unproven. I don’t dispute that greater understanding is required, but I do question the argument that land based mining is less of an issue.
Land Based Mining can impact the sea too.
My earliest experience of mining impacts on the ocean was in 2000, during the project referenced in my last article. This was to rectify a tailings outfall pipe from a land based mine by replacing concrete saddles over an outfall pipe due to instability. I remember quite vividly the impact of the material exhausted from the pipeline to the sea and coastal waters, and the massive amount of material spoils in the vicinity of the pipe end. I believe it is misconception that land based mines don’t have an impact on the planet’s water ecosystem, and this appears to be somewhat missed in the discussion in relation to subsea mining – The status quo is unlikely to be sustainable for a “net zero” future.
Is Subsea Mining all the same?
Having also worked briefly for a Subsea Mining company, I gained insight into the industry at an early stage. The target material for that company was Seafloor Massive Sulphide (SMS) or “Smokers” rich in high value minerals. The mining principle at this site was effectively the same as land based mining but modified to a subsea environment. The material was to be mined in shelves and graded taking the top layer off the mine site with large cutter / gatherer machines manoeuvred around the site and the material recovered to surface using subsea pumps. This project was unable to reach production due to a lack of investment.
The target minerals in the territory of Papua New Guinea differ greatly, for example, to the Clarion Clipperton Zone (CCZ) area, where there is a large amount of focus on presently.
CCZ is where nodules are found in large volumes laying on the seabed, as illustrated in the image below. The process here is more akin to harvesting / collection rather than “mining”.
Image of Nodules from https://www.rhyniechert.com/rocks/manganese_nodules
There are a wide range of seabed soils, in the same way that land soils change around the world, from desert sands to clay and rock and therefore the resultant impacts of mining, such as plume migration and sea-life displacement will not be the same across the world’s oceans. The effects of machinery on the seafloor collecting nodules will differ greatly to a machine cutting and grinding material for recovery for example. I would argue there is a distinct difference between nodule harvesting and SMS mining, and a step change in the terminology would perhaps be advantageous for the Subsea Minerals industry to differentiate the technologies.
Environmental impacts will be key to mitigating concerns
There are some very clever people assessing and working out the environmental impacts and technology to recover these minerals in a sustainable manner and have been doing so for many years.
Much of the independent scientific discoveries and work to date appears to have been sponsored by industry players, of course there are arguments against this approach to ensure impartiality of results, but irrespective of who pays the bills on Scientific research, the level of data that is currently available has been achieved through including this type of financial support.
Going Green requires difficult choices
As we progress in our society driven by technology and “clean” energy, the increased demand in minerals will continue, whether it is copper for Electrical cable distribution, Cobalt for battery technology or the minerals used in your ever upgraded smartphones and gadgets, it is difficult to see how this most recent moratorium by big manufacturers can be sustainable, in the same way land based mining is not likely to be sustainable either to match demand.
I believe we need a grown up conversation on Energy and Resources as we strive for “Green” solutions and a sustainable supply of raw materials. The conversation is becoming as polarised as the batteries we’re promoting to power our vehicles. It would be good to hear your thoughts.
