3. Reflection in Deep Waters: Rare Earths

March 20th, 2020

The deep ocean... A vast subject. The deep ocean is the aphotic zone, meaning where light no longer penetrates, beyond a depth of 200 or 300 meters. It covers two-thirds of our planet and represents 93% of the biosphere in terms of volume! The average depth is 3800 meters and can exceed 11 kilometers. Most often, these zones coincide with the legal term "high seas" and are therefore subject to an international jurisdiction still under construction, but a significant part is within national exclusive economic zones (EEZ). France, including its overseas territories, has a significant share of deep oceans in its EEZ, with almost half located off Polynesia. Europe in general, with its Outermost Regions (RUP), plays a significant role in managing these areas.

These are not "life deserts," as emphasized by Daniella Zepilli. On the contrary, biodiversity hotspots are identified on underwater mountains that can be located in the depths. The species present are surprising and still relatively unknown. Other hotspots, such as black smokers, host ecosystems with exceptional properties that require major adaptations from the organisms present. The deep sea presents unfavorable conditions for life (absence of photosynthesis). Primary energy production comes from microbial chemosynthesis. The adapted animals provide avenues to explore the presence of life on other planets, as they resist high pressures and low temperatures. Although little known due to our difficulty in reaching such depths with suitable measurement devices, the deep sea is connected through the water column to the entire ocean and also undergoes the changes that the planet is facing. Recent methods such as 3D reconstructions, environmental DNA analysis (eDNA), or artificial intelligence offer promising prospects for understanding these diverse and unstable ecosystems.

The exploration of mineral resources in these areas is under consideration, and exploration work has already begun. Polymetallic sulfides from black smokers, mineral-rich crusts in the French Polynesian, or polymetallic nodules in abyssal plains like Cliperton are attractive resources whose existence we know. Currently, France has two exploration permits in these areas. The question of exploitation is sensitive: on the one hand, a potential future shortage of materials potentially available in the oceans encourages prospecting, especially in a context where China holds a virtual monopoly on extracted rare earths. On the other hand, our lack of knowledge about potentially damaged ecosystems calls for caution. This tension is reflected in the discourse of Charlotte Sapin, representative of the International Seabed Authority (ISA). She emphasizes that no mining operations have started in the high seas. Currently, 30 exploration contracts are authorized over 0.3% of the world's oceans (1.3 million km2). The evolving mining code aims to regulate these activities, giving a predominant place to environmental considerations. In compliance with these regulations, exploitation can begin. WWF calls for a moratorium on this exploitation, citing our inability to accurately assess the risk of ecosystem destruction and the loss of as-yet-unknown species. "Most citizens are not aware of the impacts." The NGO highlights the contradiction in aiming to integrate the economy into a circular mode while promoting the extraction of minerals produced on geological timescales compared to their recycling. In our current linear economy, 92% of resources are not recycled.

All parties agree on the urgent need to fill the lack of data and expect a lot from scientific research to address this gap. The wealth of the deep oceans is a treasure we are gradually discovering. For now, 95% of the deep sea is completely unknown.

See 4. The treaty on the high seas