Washington, March 31 : Concern over Chinaâ??s dominance in critical minerals is driving renewed US interest in deep-sea mining, even as experts have cautioned lawmakers that the ecological risks beneath the waves remain poorly understood.

Lawmakers and industry leaders at a Congressional hearing stressed the urgency of securing supply chains for minerals such as cobalt, nickel, and copper, which are essential to defence systems, clean energy, and advanced technologies.

Congressman Scott Franklin said these resources are â??vital to industries across our country,â?? warning that adversaries like China â??will undoubtedly seek to undermine the United States.â??

Industry executives argued that the US has both the technology and regulatory framework to move ahead. Gerard Barron, CEO of The Metals Company, told lawmakers that â??we know enough to manage risks,â?? pointing to decades of research and recent advances that reduce environmental disturbance.

Barron said that deep-seabed nodules could significantly reduce the US's dependence on imports, noting that they contain metals critical to sectors such as defence, artificial intelligence, and energy. He added that modern systems leave â??almost invisible ripples on the sea floorâ?? and limit environmental impact to relatively small areas.

But scientists warned that the push to accelerate mining may be premature.

Dr Astrid Leitner, a deep-sea ecologist, said â??the best available data is insufficient to enable the responsible development of deep-sea mining,â?? highlighting gaps in baseline data on biodiversity, ecosystem functions and long-term impacts.

She cautioned that mining could lead to â??biodiversity lossâ?? and â??possible extinctions,â?? with effects that may be long-lasting or irreversible.

Lawmakers across party lines acknowledged the scale of uncertainty. Ranking member Gabe Amo said the ocean remains â??one of the least understood ecosystems on earth,â?? adding that the consequences of missteps could be â??long-lasting and in some cases irreversible.â??

The hearing also underscored how little of the ocean has been mapped or explored.

Brian Connon of Saildrone said only â??54 per cent of the US EEZ has been mapped,â?? leaving vast areas of American waters unexplored.

Veteran explorer Robert Ballard told lawmakers that humans have seen just â??0.001 per cent of the deep ocean,â?? stressing that exploration must precede any large-scale commercial activity.

Despite the uncertainties, geopolitical competition is accelerating the debate.

Lawmakers repeatedly pointed to Chinaâ??s lead in mineral processing and ocean research. According to testimony, China produces nearly 70 per cent of the worldâ??s rare earth elements and has invested heavily in mapping and exploration capabilities.

Supporters of deep-sea mining argue that failing to act could leave the US dependent on foreign supply chains.

Critics counter that moving too quickly risks damaging ecosystems that play a crucial role in regulating the climate, supporting fisheries, and maintaining ocean health.

/IANS