Marine Awareness – Deep Sea Mining: Treasure or Trouble

The deep sea is a place of much unknown, more foreign to us than the surface of the moon.

Total darkness, frigid cold and pressure so strong it could shatter bone and crush submarines. A place so otherworldly and extreme, yet soft, delicate, and jelly-like animals thrive, octopuses lay their precious eggs, squid dazzle with glowing displays, and around volcanic vents, ancient chemical reactions may have sparked the very first life on earth.

         Pearl octopus, Deep-sea anglerfish, and Harp sponge (images by MBARI)

With every new dive, we learn more about the deep sea, its unique environments, and its life. Yet as discoveries continue, the deep-sea is under threat. Mining companies are gearing up to start digging into the ocean floor. We’re only beginning to understand the risks.

Deep sea mining aims to harvest valuable minerals from the ocean floor, reaching hundreds or even thousands of meters below the surface. Exploration missions have uncovered huge reserves of minerals like silver, cobalt, copper, and even gold — all are in high demand. These materials are essential for building cars, computers, phones, and even green technologies like electric car batteries and solar panels. Mining for these materials is already happening on land, but as demand grows, companies are turning their attention to the rich, untouched deposits beneath the sea.

The main target for deep-sea mining is a treasure called nodules -loose, potato-sized lumps of metal that sit on the seafloor, 4,000 to 6,000 metres below the surface. A key area is a region between Hawaii and Mexico, where rich reserves are found.

Collecting these deposits is no easy feat. Remotely operated mining vehicles are lowered to the seafloor, where they crawl along the bottom, hoovering up metallic nodules and sending them through pipes to the ship above.

Scientists once saw the deep sea as a desert to life. In reality, It’s the largest habitable space on our planet, home to a high diversity of life, much of it undiscovered. In the deep sea around Hawaii and Mexico researchers recently identified 5,000 entirely new species. Activities like deep-sea mining could disrupt these remote environments as well as the species that live there—both the ones we know about and the ones we don’t. How can we truly understand the consequences when so much remains unknown.

So far, what we understand about the risks is already raising warning flags. The direct contact of heavy mining equipment on the seafloor would kill marine life and destroy habitats. Huge clouds of sediment stirred up by digging could suffocate even more creatures, disturbing the food web and threatening fishing and food security for island nations.

The constant noise from mining could drive away local baleen whales, Risso’s dolphins and other marine animals that depend on sound and vibrations to survive.

And even though deep-sea mining happens far offshore, building the factories to process the minerals would unfairly impact coastal communities the hardest.

Deep sea mining may also have impacts on the climate, the seabed acts as a natural store of carbon, disturbing the sediment and the loss of marine diversity may affect the oceans’ ability as a carbon sink, speeding up climate change.

Many deep-sea species are also rare, live long lives and are slow to reproduce meaning recovery after mining could take an extremely long time. Deep-sea black corals, for example, grow just a few centimetres every hundred years — and some individuals are thought to be over 4,000 years old.

Some people argue that moving mining away from the land can reduce environmental hazards such as deforestation or the pollution of freshwater. However, hiding the damage of mining below thousands of meters of water isn’t an environmentally friendly option.

So, what can be done, and do we really need to mine these minerals?

While it’s true that we do need more minerals, many environmental groups are pushing for alternatives. Greater recycling of old batteries, and electronic tech, increasing the use of public transport can all reduce the need for more mining.

While large-scale mining hasn’t started yet, exploration and testing of new mining technologies has increased. Many countries have stepped up, seeing the risks and unknowns, and have signed laws to help protect the seafloor. But others, like the United States, are holding back — leaving parts of the deep ocean at risk.

We need to understand much more about these fascinating deep-sea environments before we risk damaging them beyond repair. Can we really allow the destruction of one of the places where life began and before we’ve even discovered the species that live there?

Written by Maurice Carlton-Seal

For more articles like this straight to your inbox join Adopt a Dolphin