Meet the Marine Biologist Working to Protect Our Oceans from Deep-Sea Mining

The oceans need more care than they ever have before—and few people are taking on that job with more commitment than Diva Amon. A marine biologist at the Benioff Ocean Science Laboratory at the University of California, Santa Barbara, (Marc and Lynne Benioff are TIME's owners and co-chairs), Amon has a special love for the deeper reaches of the ocean—below 200 meters, where sunlight does not penetrate, pressures are up to 110 times that of sea level, and temperatures drop to 39°F. Despite those punishing conditions, all manner of life forms thrive there. One of the greatest potential dangers to that fragile ecosystem is deep-ocean mining—industrializing the untouched and unseen ocean floor to extract nickel, cobalt, copper, manganese, gold, silver, and more. For now, the mining is not taking place—and Amon and her colleagues are advocating and mobilizing to help keep it that way. Amon spoke to TIME in a wide-ranging conversation that has been edited for brevity and clarity.

TIME: There are a lot of riches to be had on the floor of the oceans. What is the current state of mining?

Amon: Mining in international waters is governed by the International Seabed Authority, an autonomous United Nations authority. They have been granting licenses for exploration only over the past 20 years in the Pacific, Atlantic, and Indian Oceans. There have been more than 30 licenses granted so far. Most of them cover areas around 75,000 kilometers [46,602 miles], or about the size of Sri Lanka, so it’s not inconsequential. In addition, Norway, Japan, the Cook Islands, and Papua New Guinea are considering deep-sea mining in their own waters.

Read more: Fishing Communities in the Philippines Are Fighting for their Future as Waters Rise

What are countries and companies studying in these exploration activities?

They’re looking for three kinds of resources. First, there are polymetallic nodules, which are sort of a metallic lump, anywhere from cherry sized to potato sized. They form in a way similar to a pearl, accreting around a tiny particle like a shark’s tooth, a shell, or a piece of sediment. The rate at which they form is a few millimeters per million years. They are also looking for polymetallic sulfides, found at hydrothermal vents, which are one of the most remarkable and iconic deep-sea ecosystems. Finally, they’re looking for cobalt rich ferromanganese crusts, which are a layer that forms on seamounts [underwater mountains]. The crusts can be anywhere from millimeters to several feet thick.

You mention ecosystems. How robust is life in these three resource areas?

The minerals that are being targeted form a critical part of the sea floor, and the sea floor is what life attaches to in the deep ocean. Things like coral, anemones, and fungi are attached to the deep floor. In the case of nodules, they use them as an anchor or as a shelter. They are really the cornerstone of the ecosystem.

What other kinds of organisms live in these areas?

We don’t fully know. There are big gaps in our knowledge. There was a study that came out in 2023 that found that in the Clarion Clipperton Zone [which extends from Hawaii to Mexico], 88% to 92% of the multicellular species that live there have not been described by science. We’re not talking about just one or two life forms. We’re talking about thousands.

How big are the areas that would be affected by mining?

The spatial scales of this are enormous. Just in the Clarion Clipperton Zone, industry projections are that they’re planning to mine 500,000 square kilometers [more than 193,000 square miles]. And because of the three dimensional nature of the ocean, the concern is that the impact will extend both vertically for thousands of meters and horizontally, potentially tripling the area of impact. There is a plume that is generated at the sea floor from the mining activity like a dust storm that will spread well beyond the mining tract. 

There’s a secondary plume too. Anything that's mined will be pumped up a pipe to a ship which is waiting on the surface. The minerals will be separated from water and sediment and metal particles. Then that sediment, wastewater, and particulate and dissolved matter will be pumped back into the ocean from the ship. There are currently no regulations to dictate at what depth that waste is pumped back into the ocean—whether it’s at the surface or thousands of meters deep or right back to the sea floor.

Could ecosystems recover from all of this?

Life in the deep sea is extremely slow. There's very little food, and that means that life moves slowly, grows slowly, reproduces slowly. And so it really does not deal very well with impact. It takes a long time to recover. With nodules for instance, we will not see ecosystem recovery except on a scale of millions of years. Essentially, this would be irreversible damage.

In the nearer term, there are increases in noise and light from mining that has never been seen before in the deep sea. All of that is going to result in biodiversity loss. You also have contaminants being released by the plumes that are going to work their way up the food chain. This could affect ecosystem services that we get from the deep sea, such as fisheries.

There is an argument that deep-sea mining actually has some environmental benefits because it replaces mining done on the surface. Is there anything to this?

There's no evidence that deep-sea mining would prevent terrestrial mining. It's likely that both will occur, causing double destruction, rather than one taking the place of the other. Something else that is often disregarded is that we know that the ocean plays a critical role in regulating the climate; it’s where a majority of heat is absorbed, it’s where an enormous amount of carbon is sequestered. The ocean is one of our greatest allies in the fight against the climate crisis. To argue for using deep-sea mining to solve the climate crisis is like smoking to lower your stress.