'A different perspective': This top marine scientist is determined to resolve deep-sea mining's murky future

Brazilian marine scientist Leticia Carvalho will be the first-ever woman, oceanographer and person of Latin American heritage to lead the International Seabed Authority — and she says it "feels fantastic."

"I am very proud," Carvalho told CNBC via videoconference. "I think it is quite meaningful that someone new, fresh and with a different perspective is coming to take over."

The ISA, a little-known U.N. regulator that oversees deep-sea mining, is responsible for both the exploitation and conservation of an area that covers around 54% of the world's oceans.

Carvalho recently beat incumbent Michael Lodge to the top job in a bitterly contested election billed as a pivotal moment for the fate of a potentially multi-trillion-dollar industry. Her four-year term as ISA chief will start on Jan. 1, 2025.

Carvalho's election victory comes at a time of intense debate about the future of deep-sea mining and the world's oceans.

The controversial practice of deep-sea mining involves using heavy machinery to remove minerals and metals — such as cobalt, nickel, copper and manganese — from the seabed, where they build up as potato-sized nodules.

The end-use of these minerals are wide-ranging and include electric vehicle batteries, wind turbines and solar panels.

Scientists have warned that the full environmental impacts of deep-sea mining are hard to predict. Environmental campaign groups, meanwhile, say the practice cannot be done sustainably and will inevitably lead to ecosystem destruction and species extinction.

The ISA Council, a body composed of 36 member states, recently wrapped up a series of meetings in Jamaica as it seeks to draft a mining code to regulate the exploitation and extraction of polymetallic nodules and other deposits on the ocean floor — before mining activity begins.

Negotiators are trying to ensure formal rules are in place by the end of 2025 and Carvalho says it remains feasible that member states can meet this goal.

"My obligation as Secretary General is to set the stage for them to be able to finalize the work by the end of next year. And I will do everything in my power to do it," Carvalho said.

The scramble to reach consensus on a mining code was prompted by Nauru in 2021 when the Pacific Island state informed the ISA of its intention to begin deep-sea mining.

That triggered a controversial provision in the U.N. Convention on the Law of the Sea, known as the "two year rule," which allows mining applications to be submitted whether the mining code has been finalized or not.

It has led some companies to pursue aggressive timelines for extraction, with Canada's The Metals Company (TMC) in 2023 saying it intends to seek a license to extract minerals from the seabed by the end of this year.

Asked about TMC's plans, Carvalho replied: "It's fair enough. It's part of the law, they have the right to table their request."

She warned, however, of litigation risks in such a scenario. "I would be very much concerned to have a mining exploitation request sat on my table without a mining code," Carvalho said.

"In my experience, regulatory stability for businesses and society is really fundamental. If you don't have stability, you then therefore have a cacophony and chaos because you open space for litigation at different levels," she added.

"And particularly deep-sea mining as an activity has many players, meaning many courts would be called to have their say, not only in the international level but also at a national level."

Carvalho, who had previously served as head of the U.N.'s marine and freshwater branch, said her top priority as ISA chief would be the management of the regulator itself.

"For me it became quite clear that the primary issue is the governance of the ISA itself. There is a need for me, quite clearly, to rebuild trust," Carvalho said.

"I don't want to criticize anyone or any individual specifically, but I think the reality of the facts is that there is a lot of transparency and accountability to be put in place."

Five recent announcements in support of a precautionary pause or moratorium to the nascent industry mean that more than 30 countries have now called for a halt to the start of deep-sea mining.

Growing momentum for a pause comes shortly after a groundbreaking study found that so-called "dark oxygen" is being produced by polymetallic nodules thousands of feet below the surface of the Pacific Ocean.

The findings, published in the Nature Geoscience journal last month, are likely to raise fresh concerns about the risks of deep-sea mining.

Carvalho described the study's findings as "mind-blowing," adding that environmental concerns should be at the forefront of the ISA's agenda.

When asked about demands from environmental groups to protect the deep ocean from heavy mining machines, Carvalho replied: "I would say this protection has to be delivered in the mining code through the ISA. I don't see any other instrument in the world that could deliver this."

Carvalho said she was unafraid about the debate regarding the future of deep-sea mining.

"I'm the opposite, I embrace it completely because that's what the ISA has to do. The ISA leadership has to read completely what is written in the law, which is to deliver a mining code that can honor the provision of the law that says that the ocean shouldn't be harmed," Carvalho said.

"What is the definition of harm? That's what we have to discuss," she added.