Is Rebuilding the Ocean Floor After Mining Truly Impossible? Researchers Sound the Alarm

Deep‑Sea Mining and the Fragile Bottom Ocean
International Seabed Authority Seeks Governing Rules
Scientists warn that recovering the seafloor after mining remains uncertain, and recovery times could span thousands of years.
- DEEP REST study concludes that removing nodules leaves a permanent loss and that any restoration effort has shown only a few‑year short‑term effect.
- Jozee Sarrazin from IFREMER notes that if restoration is possible it will take a very long time, but current data cannot specify whether the horizon is 100 years, 1 000 years, or longer.
Mounting Pressure from Corporate Interest
Polymetallic nodules, packed with cobalt, nickel, copper and manganese, are coveted by companies that promise minimal risk to the deep‑sea environment.
Scientists Present Findings on Kingston Meeting
- Matthias Haeckel of GEOMAR warns that end‑to‑end vacuuming of nodules and sediment cover reduces population densities, biodiversity and ecosystem functioning.
- Haeckel emphasizes that nodules have formed over millions of years and that recoveries of thousands of years are inevitable if mining proceeds.
Restoration Efforts in the Depths
- Sabine Gollner from the Royal Netherlands Institute for Sea Research reports that artificial nodules made of deep‑sea clay have been deployed at 4 500 m depth, yet the slow growth rates of deep‑sea life mean that results may take many additional years to assess.
- Gollner recommends integrating restoration goals into the mining code under negotiation, while clearly stating that current science cannot rely on restoration to meet environmental objectives.
Concern for Massive Sulfide Deposits
Researchers advise declaring massive sulfide deposits—found near active hydrothermal vents—as off‑limits because such areas house exceptional biodiversity.
DEEP REST study stresses that extraction of those sulfides means irreversible loss and must be avoided.
Conclusion
The available science indicates that deep‑sea mining could cause permanent damage to the seafloor ecosystem, with full ecological recovery potentially requiring thousands of years. The International Seabed Authority must consider these findings when finalizing the rules that will govern this emerging industry.