Ocean Depths Targeted for Mining Are Rich in Complex and Unknown Marine Life, Scientists Find

Like the dry land on the surface of our planet, the ocean’s depths are made up of a variety of terrain, from plains and canyons to volcanic seamounts. Scientists believe there are as many as 10 million undiscovered marine species living on the ocean floor.

Multiple new studies have found that a vast area at the bottom of the Pacific Ocean that is being targeted for destructive deep-sea mining — the Clarion-Clipperton Zone (CCZ) — is home to thousands of unknown species that are more complex than scientists once believed.

Miners of minerals used in electric vehicle batteries and other green energy technologies have been looking at this abyssal plain for “nodules” on the seafloor that contain the minerals.

In a new study, an international team of scientists looked more closely at the biodiversity of this underwater region between Hawaii and Mexico. The researchers mapped marine animals’ distribution in the CCZ and discovered their communities were more complex than once thought.

“Abyssal seafloor communities cover more than 60% of Earth’s surface. Despite their great size, abyssal plains extend across modest environmental gradients compared to other marine ecosystems. However, little is known about the patterns and processes regulating biodiversity or potentially delimiting biogeographical boundaries at regional scales in the abyss,” the authors of the study wrote. “Improved macroecological understanding of remote abyssal environments is urgent as threats of widespread anthropogenic disturbance grow in the deep ocean.”

The study, “Carbonate compensation depth drives abyssal biogeography in the northeast Pacific,” was published in the journal Nature Ecology and Evolution.

Along with the interest in mining the region has come more exploration and discoveries through commercially funded deep sea expeditions, reported AFP.

Among the wonders of this dark, watery world include a shrimp with long, bristly legs, an enormous sea cucumber called the “gummy squirrel,” soft-bodied anemones, glass sponges and many types of mollusks, crustaceans and tiny worms.

Conservationists have been calling for a moratorium on deep-sea mining, but last week the International Seabed Authority gave the go-ahead to a two-year plan for adopting a set of mining regulations.

“We are on the side of the ocean,” said Gina Guillén Grillo, Costa Rica’s representative to the Seabed Authority who has helped lead the opposition to seabed mining, as The New York Times reported. “We know there is not enough science. To start right now would be a disaster.”

More than half of Earth is covered in abyssal plains that are over 9,843 feet underwater. Erik Simon-Lledó, a marine biologist from Britain’s National Oceanography Centre, who was also the lead researcher of the study, called these regions the “last frontier.”

“Every time we do a new dive we see something new,” Simon-Lledó said, according to AFP.

Mining disrupts the seabed, causing large plumes of sediment that can wipe out habitat and smother delicate organisms. Nodules containing the sought-after minerals are also the homes of specialized marine animals.

“With the science as it is at the present day, there is no circumstance under which we would support mining of the seabed,” said Sophie Benbow of the NGO Fauna and Flora, as reported by AFP.

The unique array of marine life in the CCZ is due to the region’s size and age, but essential to its stunning biodiversity is the fact that it has remained undisturbed.

According to the study, more than 90 percent of the approximately 5,000 species documented in the CCZ are new to science.

Adrian Glover of Britain’s Natural History Museum, who was a co-author of the study, said mining regulations would need to consider that the distribution of marine creatures in the CCZ is “more complex than we thought.”

Glover explained that each nodule likely took millions of years to develop and began as a shard from a fish ear bone or shark tooth that had settled on the ocean floor. The nodules grew slowly over time as minerals found at very low concentrations in the water naturally accumulated on them.

The CCZ is ancient and adds only one centimeter of sediment every thousand years. Because the environment has been undisturbed for what Glover said is tens of millions of years, recovering from any mining would take an unknown amount of time.

“You are basically writing that ecosystem off for probably centuries, maybe thousands of years, because the rate of recovery is so slow,” said Michael Norton, Environment Programme Director for the European Academies’ Science Advisory Council, as AFP reported. “It’s difficult to argue that that is not serious harm.”