Deep Pacific seabed reveals vast hidden life

The findings stem from a five-year international research effort that logged more than 160 days at sea, focusing on remote stretches of the Clarion-Clipperton Zone, a vast abyssal plain between Hawaii and Mexico known to hold large deposits of polymetallic nodules rich in nickel, cobalt and manganese. These metals are increasingly sought for electric vehicle batteries and renewable energy technologies, intensifying interest in commercial seabed mining.

Researchers recorded close to 800 distinct species living on or just above the ocean floor, many of which had never been formally described. The survey revealed a complex community of worms, crustaceans, sponges and other invertebrates adapted to extreme pressure, darkness and limited food supply, challenging assumptions that such environments host sparse life.

Scientists involved in the work said the sheer diversity documented in a single region underlined how little is known about deep-sea ecosystems. Some organisms were found clinging directly to mineral nodules, suggesting that large-scale removal of these rocks could disrupt habitats that may take centuries to recover.

Alongside biological cataloguing, the study assessed the effects of controlled test mining carried out decades earlier, where small areas of seabed were disturbed to simulate nodule collection. Data showed a marked decline in both the number of animals and the variety of species within disturbed zones when compared with untouched areas. Mobile creatures such as sea cucumbers and certain crustaceans were slower to return, while sessile species dependent on nodules appeared particularly vulnerable.

Despite these declines, the overall ecological impact was described as more limited than some earlier projections, with signs that parts of the ecosystem retained a degree of resilience. Sediment plumes created by test operations settled more quickly than anticipated, and some species recolonised affected areas over time, albeit unevenly.

Researchers cautioned that these results should not be taken as a green light for full-scale mining. The experimental disturbances covered a fraction of the area that commercial operations would affect, and long-term consequences remain uncertain. Deep-sea species often grow slowly and reproduce infrequently, meaning recovery from repeated or widespread disruption could take far longer than existing observations suggest.

The work arrives as regulators debate how, or whether, to permit seabed mining in international waters. The International Seabed Authority is under pressure from both industry players seeking clarity on extraction rules and environmental groups urging a pause until scientific understanding improves. Several governments have called for a precautionary approach, citing gaps in knowledge about cumulative ecological impacts.

Within the scientific community, the study is being viewed as a benchmark for future environmental assessments. By combining taxonomy, ecological monitoring and historical disturbance data, it provides one of the clearest pictures yet of how life persists in the deep Pacific and how it responds to physical disruption.

The economic stakes are high. Demand forecasts for battery metals have driven companies to invest heavily in deep-sea exploration, arguing that seabed mining could reduce reliance on terrestrial sources linked to deforestation and human rights concerns. Critics counter that shifting environmental risks from land to sea may simply create a new set of problems in ecosystems that are harder to study and protect.