The natural world has evolved in ingenious and bizarre ways to survive some of the most hostile environments on the planet. Take for instance deep-sea molluscs, which survive in temperatures of up to 450ºC, living on hydrothermal vents some 5000 metres below the surface.

Many of these molluscs – including snails, limpets, mussels, clams and chitons – were left untouched for millenia, and were in fact only discovered in the past 10 years.

But, a new global assessment of these species has found that 62% face extinction due to deep-sea mining.

By filtering toxic chemicals and providing structural habitats, these resilient organisms serve as the foundation for entire deep-sea communities. Their extinction could see the collapse of these fragile, undiscovered ecosystems and permanently erase invaluable biological secrets before we even have a chance to understand them.

Some deep-sea vent molluscs have already proven to hold value for human technology. The scaly-foot snail has developed a biomineralisation process ​that is helping researchers ​produce nanoparticles for new ⁠technologies like solar cells. Others are being studied to help develop alternatives to plastics.

Exploration of the seabed and the extraction of minerals create sediment plumes that smother the animals, impacting their ability to breathe and absorb nutrients from the surrounding water.

For example, Lirapex felix – a snail named for the researchers’ luck in finding it – has today entered the Red List as Critically Endangered due to ongoing mining exploration in the Indian Ocean. 

“This global assessment reveals that molluscs endemic to deep-sea hydrothermal vents are one of the most highly threatened of all animal groups, at a critical moment for their future,” said Professor Julia Sigwart at Senckenberg Nature Research, the IUCN Red List Partner who coordinated these assessments.

The assessment also highlighted the value of marine protected areas: over 30 within these designated protected zones listed as ‘Least Concern’. For instance, the Provanna exquisita, an ornate snail that lives only in the Mariana Arc of Fire National Wildlife Refuge in the Pacific Ocean.

The news comes against the backdrop of the looming 31st International Seabed Authority’s Session, set to take place from 13-31 July. Industry pressure is currently mounting to fast-track mining the ocean floor, with some countries, like the US, taking on independent steps using their domestic laws to enable this. 

“As pressures on biodiversity mount across the planet, even the creatures with the most ingenious survival strategies are under threat,” said Dr Grethel Aguilar, IUCN Director General.

“But let us not forget there is a clear path out of the biodiversity crisis: nature conservation works, as we are reminded again and again. By protecting the astounding range of biodiversity on this planet, we can preserve a welcoming environment for humans and wildlife alike,” he added.

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