99.999% of the Deep Seabed Is Unexplored Sparks Debate Over Deep-Sea Mining and Nodules

New Scientist examines a stunning fact: 99.999% of the deep seabed remains unseen by human eyes. The transcript covers why the deepest parts of the ocean are so hard to access, what we have learned from the small portion we have seen, and how this shapes debates around nodules and deep-sea mining. It features expert perspectives on hydrothermal vents, the ecological riches of the Clarion Clipperton Zone, and the policy dynamics surrounding mining in international waters and US waters. The piece also explores battery technology trends that could reduce the urgency of seabed mining and emphasizes the need to map and protect deep-sea ecosystems before exploitation.

Overview

The exploration of the deep sea has revealed a stark gap: around 0.001% of the deep seabed has been observed by humans, with the vast majority still beyond view. The deep ocean, covering 71% of Earth’s surface and hosting 93% of the ocean floor below 200 meters, remains largely uncharted despite decades of submersible missions. A synthesis of nearly 44,000 deep submergence records shows that our direct observations are limited to a tiny sliver, yet those observations have yielded groundbreaking discoveries such as hydrothermal vent ecosystems and the discovery of metallic nodules on the Clarion Clipperton Zone. This context frames a broader debate about whether and how to mine the seabed for the minerals these nodules contain.

Key Discoveries and Concepts

The hydrothermal vent systems, first observed in the late 1970s, demonstrated that life can thrive in darkness fed by mineral-rich water. Nodules in the Clarion Clipperton Zone are not inert; they host complex communities and, intriguingly, may produce oxygen in the deep sea, suggesting nodules can power local ecosystems. In parallel, new deep-sea life forms are constantly being catalogued; estimates suggest that a high fraction of collected species in this zone are previously unknown to science, underscoring both the value and fragility of these habitats.

Nodules, Mining and the Battery Material Debate

Mining firms argue nodules could supply cobalt, nickel and other materials crucial for electric vehicle batteries, potentially reducing pressure on land-based mining. Critics warn that deep-sea mining risks irreversible harm to pristine ecosystems and to communities reliant on the ocean. The policy arena has been deadlocked for years as nations weigh environmental protections against resource needs. A recent executive order from the United States signaling openness to deep-sea mining in national and international waters has intensified negotiations and drawn fast-moving permit activity by companies seeking to begin operations in international waters.

Technological and Ecological Outlook

Advances in battery chemistry point to alternatives to seabed minerals, such as iron phosphate and sodium-ion batteries, which could lessen demand for coastal or seabed sources. At the same time, the deep sea’s biodiversity is staggering and largely uncharted, with studies in the Clarion Clippperton Zone revealing hundreds or thousands of previously undocumented organisms. Experts emphasize the need for thorough mapping and careful governance before any large-scale extraction proceeds.

Governance and Public Response

Global stakeholders, including Indigenous communities, scientists, and investors, are calling for pauses or moratoria until deep-sea ecosystems are better understood. Major corporations and insurers have pledged to avoid involvement in the industry, reflecting broad concerns about ocean risk. The conversation stresses a precautionary approach that prioritizes scientific understanding and responsible stewardship as the baseline for policy decisions.