Companies and countries have filed prospecting permits or secured mineral rights on 20 percent of the vent fields; the first deep-sea mining operation is expected to break seabed in 2018 off the coast of Papua New Guinea.
That fate of our ocean’s hydrothermal vent fields depends on how carefully they are mined. Mining can be destructive, but it can also be done judiciously, with attention to its consequences on life other than our own. “We’re going to have to make a choice,” wrote deep-sea ecologist Andrew David Thaler on Twitter recently, “between disposable technology and ecosystems we’ll never see.”
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What will mining companies send down to the sea floor?
Nautilus Minerals has built some big, Michael Bay-esque machines on the seafloor. As someone who both builds robots and works in deep-sea conservation, I’m amazed and a little terrified. I don’t think there will be autonomous seafloor machines, though. We’re going to be looking at human-controlled vehicles. Some involve dredging up the seafloor. One proposal I saw was just dragging a big bucket across the seafloor and pulling it up, the same way we do strip-mining.
Can the deep sea be safely mined?
Like any mining process, it’s ultimately destructive, but there are ways to do it to minimize the extent of the destruction. Companies are building the tools, laying the groundwork, identifying the ore bodies and target prospects, getting the permits—but nobody’s gone down and actually mined the deep sea. Companies have every incentive to look as green as possible. But until someone goes down and mines, we don’t know if they’re actually walking the walk rather than talking the talk. So the first deep-sea mines will be an experiment.
With deep-sea mining, because conservationists and explorers got there first, we’ve got 40 years of baseline data about the ecosystem including high-resolution seafloor maps and an understanding of populations around hydrothermal vent fields. This gives us the opportunity to think about how to do deep-sea mining right.
Can the ecosystems around deep-sea vents recover from mining?
These are dynamic systems. Some communities, with lifespans of 10 to 12 years, have evolved to handle disturbance. Underwater volcanoes erupt regularly and wipe them out. When we talk about mining a hydrothermal vent, there’s a possibility for the community of life to come back. It’s possible that if you remove just one, then 10 years from now there will be no trace of it being mined at the site—though there is damage to the rest of the seafloor, which is prolonged, because the deep seafloor tends to be undisturbed.
Cobalt-rich crusts and manganese nodule fields, however, are “slow” ecosystems. They can last for centuries. Any affront to a slower system is going to have more consequences. The question becomes: Is there an acceptable loss before we’ve wiped out too much of an ecosystem?
