Environmental and legal groups warn of potential huge effects on Indigenous people and the environment

This article is more than 2 years old

This article is more than 2 years old

The “new global gold rush” over deep-sea mining holds the same potential pitfalls as previous resource scrambles, with environmental and social impacts ignored and the rights of Indigenous people marginalised, a paper in the Harvard Environmental Law Review has warned.

A framework for deep-sea mining – where polymetallic nodules or hydrothermal vents are mined by machine – was first articulated in the 1960s, on an idea that the seabed floor beyond national jurisdiction was a “common heritage of mankind”.

But exploration has gathered momentum in the past three years, with licences granted off Papua New Guinea’s coastlines, and successful mining off Japan late last year. The International Seabed Authority, which is drawing up a draft mining code, has issued 29 exploration contracts for undersea mining in international waters beyond any national jurisdiction.

Sign up to receive the top stories in Australia every day at noon

Proponents argue deep-sea mining could yield far superior ore to land mining – in silver, gold, copper, manganese, cobalt and zinc – with little, if any, waste product. Different methods exist, but most involve using some form of converted machinery previously used in terrestrial mining to excavate materials from the sea floor, at depths of up to 6,000 metres, then drawing a seawater slurry to ships on the surface. The slurry is then “de-watered” and transferred to another vessel for shipping. Extracted seawater is pumped back down and discharged close to the sea floor.

But environmental and legal groups have urged caution, arguing there are potentially massive – and unknown – ramifications for the environment and for nearby communities, and that the global regulatory framework is not yet drafted, and currently deficient.

Troubled Papua New Guinea deep-sea mine faces environmental challenge Read more

“Despite arising in the last half century, the ‘new global gold rush’ of deep-sea mining shares many features with past resource scrambles – including a general disregard for environmental and social impacts, and the marginalisation of Indigenous peoples and their rights,” the paper, written by Julie Hunter and Julian Aguon, from Blue Ocean Law, and Pradeep Singh, from the Center for Marine Environmental Sciences, Bremen, argues.

The authors say that knowledge of the deep seabed remains extremely limited.

“The surface of the moon, Mars and even Venus have all been mapped and studied in much greater detail, leading marine scientists to commonly remark that, with respect to the deep sea, ‘We don’t yet know what we need to know.’ ”

Scientific research – including a recent paper in Marine Policy journal – has suggested the deep seabed, and hydrothermal vents in particular, have crucial impacts upon biodiversity and global climate regulations.

Hydrothermal vents act as a sink, sequestering carbon and methane. The mineral-rich vents and their surrounds are also home to animals and organisms including crustaceans, tubeworms, clams, slugs, anemones and fish.

“It is becoming increasingly clear that deep-sea mining poses a grave threat to these vital seabed functions,” the paper says. “Extraction methods would involve the operation of large, remote vehicles on the seafloor to chemically leach or physically cut crust from substrate and/or use highly pressurised water to strip the crust.

“All of these methods would produce large sediment plumes and involve the discharge of waste and tailings back into the ocean, significantly disturbing seafloor environments.”

Can deep-sea mining avoid the environmental mistakes of mining on land? Read more

The Harvard Environmental Law Review article says the exploratory phase of deep-sea mining has already adversely affected Indigenous people in the Pacific. In Tonga, large mining prospecting vessels have disturbed traditional fishing grounds, and in PNG villagers bordering the exploration site in the Bismarck sea have reported high incidence of dead fish washed ashore.

The paper argues for governments globally to reform the international seabed regime to reflect modern developments in law and science, and to protect potentially vulnerable communities.

“They should recognise the risks of operating in an unknown environment, fully embrace the precautionary approach, and protect and conserve the ocean for the benefit of current and future generations,” it says.