The deep sea is home to a dazzling array of life, including species found nowhere else on the planet. Many deep-sea organisms are slow growing, late to reproduce and have limited capacity to recover from disturbance, making them particularly vulnerable to industrial activity. These fragile deep-sea ecosystems are already under stress from global warming, bottom fisheries, pollution and plastic, with deep-sea mining poised to compound existing threats.
Scientific experts consider that biodiversity loss would be inevitable and irreversible if deep-sea mining were permitted, both from direct and indirect impacts. Besides the destruction that strip mining, removing or digging up the seabed would cause to deep-sea species and ecosystems, sediment plumes and toxic wastewater from mining activity could drift far away from the actual mining sites, potentially harming or killing marine life and introducing heavy metals into the marine food chain. Noise and light pollution from mining machinery would impact deep-sea creatures who have evolved to survive in the darkness, as well as deep-diving or deep-dwelling animals such as whales that use noise and echolocation to communicate and find prey. What’s more, scientists warn that deep-sea mining could risk disturbing some of the largest carbon sinks on the planet, along with the deep sea’s ability to buffer us from the worst impacts of climate change. Studies show that even after small-scale experimental deep-sea mining events, carbon cycling in the deep has still not recovered after 26 years.
Industries that rely on marine ecosystems could be adversely affected, including fishing, tourism, cables and maritime transport. The seafood industry has called for a moratorium or prohibition on deep-sea mining until the full impacts are understood. Given the importance of these industries for food security, livelihoods and national economies, particularly for coastal and island states, these risks raise serious red flags and make deep-sea mining an economic and social threat, as well as an environmental one. In addition to the impacts on coastal communities, deep-sea mining would represent a failure to respect the rights of Indigenous Peoples, who emphasize the need to protect their cultural heritage and ocean ties. Deep-sea mining also raises human rights concerns, including in relation to intergenerational equity and the rights of children to a clean and healthy environment.
The risks of deep-sea mining are startlingly clear, and yet the rewards are less so. Questions remain around who would benefit beyond a small number of mining companies, their investors and sponsoring States that support exploration and development through the International Seabed Authority (ISA). Discussions around a financial payment scheme are ongoing, but recent research shows that the financial gains to most countries are expected to be insignificant. And while sponsoring States may benefit, they could also face novel and untested attempts at litigation by non-State actors in national courts, for example for damage to the marine environment, to people (via loss or damage to culturally important places, or to livelihoods), or to property (such as subsea cables, marine genetic resources, or scientific equipment). The loss to society as a whole, including future generations, is likely to far outweigh any financial gains to individual countries or companies that might be permitted to mine the international seabed.