Deep-sea mining promises critical minerals for the energy transition without the problems of mining on land. It also promises to bring wealth to developing nations. But the evidence suggests these promises are false, and mining would harm the environment.
The practice involves scooping up rock-like nodules from vast areas of the sea floor. These potato-sized lumps contain metals and minerals such as zinc, manganese, molybdenum, nickel and rare earth elements.
Technology to mine the deep sea exists, but commercial mining of the deep sea is not happening anywhere in the world. That could soon change. Nations are meeting this month in Kingston, Jamaica, to agree to a mining code. Such a code would make way for mining to begin within the next few years.
On Thursday, Australia’s national science agency, CSIRO, released research into the environmental impacts of deep-sea mining. It aims to promote better environmental management of deep-sea mining, should it proceed.
We have previously challenged the rationale for deep-sea mining, drawing on our expertise in international politics and environmental management. We argue mining the deep sea is harmful and the economic benefits have been overstated. What’s more, the metals and minerals to be mined are not scarce.
The best course of action is a ban on international seabed mining, building on the coalition for a moratorium.
The Metals Company spent six months at sea collecting nodules in 2022, while studying the effects on ecosystems.
Managing and monitoring environmental harm
Recent advances in technology have made deep-sea mining more feasible. But removing the nodules – which also requires pumping water around – has been shown to damage the seabed and endanger marine life.
CSIRO has developed the first environmental management and monitoring frameworks to protect deep sea ecosystems from mining. It aims to provide “trusted, science-based tools to evaluate the environmental risks and viability of deep-sea mining”.
Scientists from Griffith University, Museums Victoria, the University of the Sunshine Coast, and Earth Sciences New Zealand were also involved in the work.
The Metals Company Australia, a local subsidiary of the Canadian deep-sea mining exploration company, commissioned the research. It involved analysing data from test mining the company carried out in the Pacific Ocean in 2022.
The company has led efforts to expedite deep-sea mining. This includes pushing for the mining code, and exploring commercial mining of the international seabed through approval from the US government.
In a media briefing this week, CSIRO Senior Principal Research Scientist Piers Dunstan said the mining activity substantially affected the sea floor. Some marine life, especially that attached to the nodules, had very little hope of recovery. He said if mining were to go ahead, monitoring would be crucial.
We are sceptical that ecological impacts can be managed even with this new framework. Little is known about life in these deep-water ecosystems. But research shows nodule mining would cause extensive habitat loss and damage.