Scientists from Britain's Natural History Museum (NHM) said in May that as a result of compiling all the records from expeditions to the Clarion-Clipperton Zone (CCZ, which has been targeted for mineral exploration, they estimate over 5,000 yet-to-be-named species are thriving among the polymetallic nodules resting there.

The revelation has ignited a fresh wave of claims and counter-claims between conservationists striving to protect those newfound species and miners who say minerals from the ocean's depths are essential for mankind's shift away from fossil fuels.

Intrigue over the topic was heightened by Norway confirming this week that it plans to open its waters to deep-sea mining, despite angry opposition from domestic green campaigners and some countries.

The NHM report, published in Current Biology, is effectively the first CCZ checklist for "metazoan" fauna, meaning any multicellular animal that obtains nutrients by consuming other organisms and which has cells that specialise in different functions.

The checklist of the area, which lies at depths of 4,000-6,000 m and covers an area of seabed roughly twice the size of India, was made possible by the wealth of data now amassed on the region.

Mineral exploration began in the CCZ in the 1960s, and the numerous expeditions there provided the researchers with a wealth of data that is curated by the International Seabed Authority (ISA) - the organisation responsible for the management of mining operations on the seafloor.

The findings from compiling the checklist are striking - it includes 5,578 different species, of which an estimated 88% to 92% had never before been seen. 

One of the deep-sea animals discovered has been nicknamed the "gummy squirrel", because researchers said its huge tail and jelly-like appearance resemble a squirrel-shaped gummi bear - readers can draw their own conclusions from the image above. 

Conservation versus transition

Muriel Rabone, lead author of the report and a deep-sea researcher at the NHM, believes it is vital that informed decisions are made on nodule mining in the CCZ before it begins in earnest.

Contracts for transition metals exploration in the CCZ - including cobalt, manganese and nickel - have been granted to 17 deep-sea mining contractors in an area covering 745,000 sq miles.

"We know from recent tests deep sea mining is feasible but we are in a unique position to consider the overall value and costs before any decision is made," she told Mining Magazine.

"Any potential [mining] benefits would need to be fully weighed against any potential costs- including the full value of biodiversity and the loss that may be incurred through species extinction associated with mining activities."

She notes that marine organisms are four times more likely to yield useful natural products such as medicines, known as marine genetic resources, than terrestrial organisms, with significant potential societal and commercial value.  

One miner that has taken a leading interest in exploring the CCZ is The Metals Company (TMC), which aims to position itself as the front-runner in a new industry that it believes can "reshape how critical battery metals are sourced, processed and ultimately recycled".

TMC has previously said that the CCZ contains enough nickel, copper, cobalt and manganese to potentially build over 250 million electric vehicle batteries - minerals that face a critical shortfall in terms of land-based reserves.

According to estimates by the United States Geological Survey (USGS), the global identified cobalt resources (reserves plus other known deposits) are around 7.1 million metric tons. However, analysts at Roskill forecast cobalt demand will rise to 270,000 tonnes by 2030 from 141,000 last year.

Well aware of conservationist opposition and drawing learnings from failed historical efforts to launch deep-sea mining, such as the infamous Solwara 1 project by Nautilus Minerals off the coast of Papua New Guinea, TMC has also taken pains to involve heavily science in its expeditions and exploration efforts.

TMC noted in a May statement that its exploration efforts have indeed helped with the discovery of new species at the site, and that it partners with NHM on the topic.

"TMC and our subsidiary, NORI, are proud to be among the largest funders of research enabling the discovery of new species on the abyssal plain in the Clarion Clipperton Zone (CCZ)."

NORI has contributed over 270,000 biological occurrences to the ISA's ‘DeepData' platform,  noted the company, representing the largest molecular-based assessment of quantitative CCZ macrofaunal box cores to date.  

"We are proud that the deep-sea research platform provided by this industry is helping to enable the compilation of a comprehensive inventory of life in the Clarion-Clipperton Zone (CCZ) as outlined in the paper by Rabone", said the firm.

"The complete NORI dataset will be one of the most comprehensive datasets ever gathered in the CCZ and will form the basis of NORI's Environmental Impact Statement (EIA)".

The nature of the debate

A spokesperson from TMC pointed out that an EIA in the deep sea differs significantly from those conducted on land.

Battery transition metals projects on land have faced similar outcries from conservationists. Federal protection for desert wildflowers and has threatened to derail plans to develop a lithium mine in the US, while Sami reindeer herders in Sweden say iron ore mine plans could impact their reindeer herds.

But likely that any EIA for the ocean would need to be even more complex to consider the biodiversity, fragile habitats, and interconnectedness of species in these ecosystems. Other factors include water quality, including changes in turbidity, sediment plumes, and chemical releases.

Rabone also admits there are also unknowns in terms of the natural research that's underway.

"What we urgently need for the CCZ is more sampling and publication of robust comparable datasets to better characterise this remarkable region.

"The point is not to be dazzled by the number of new species but to acknowledge both the robust scientific work being done in the area and also the huge amount of research still required to understand this ecosystem and the likely effects of mining."

Tailings tangles

Deep-sea mining is often lauded as a potential solution to one of mining's deepest and most environmentally concerning xxx - tailings. The vision is of autonomous underwater vhicles silently collecting nodules, without any of the drilling or blasting - and in some cases deforestation - seen on land.

But Rabone also said this confidence could be misplaced.

"There is a long history in terrestrial mining of tailings footprint, secure long term tailing storage, mine waste remediation and related not being properly planned or managed and this has led in some cases to serious environmental consequences. The impact of tailings are also likely to have wider and more dispersed impacts in a marine environment.

"Any planned mining operation would also need to fully account for the impact of loss of biodiversity- both intrinsic, and economic- e.g. the potential loss of marine genetic resources and novel compounds that could be developed for many applications to support society."