Over half of molluscs such as chitons, clams, mussels, snails, sea slugs, tusk shells, octopus, and squid are threatened by deep-sea mining, the International Union For Conservation of Nature (IUCN) has announced.
Issuing the updated IUCN Red List of Threatened Species, it said the list that serves as a baseline for species threat status now includes 175,909 species, of which 49,505 are threatened with extinction.
Highly diverse invertebrates, molluscs are a quarter of all living marine species and also have importance as food sources and culture significance.
In a statement, the IUCN said, “Sixty-two per cent of endemic hydrothermal vent molluscs (125 out of 201 species) known worldwide are at risk of extinction due to deep-sea mining for valuable minerals. Found only at depths up to 5,000 metres below sea level, around vents spewing out water that can be over 450 degrees Celsius, many of these molluscs — including snails, limpets, mussels, clams and chitons — have been discovered in the past 10 years and already face extinction due to human disturbance of their habitat.”
It added that exploration of the seabed and extraction of minerals, which are in increasing demand for use in new technologies, 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. Many vent species face similar threats as vents beyond national jurisdiction are explored for mining, with contracts controlled by many different countries,” it noted.
The global assessment of endemic hydrothermal vent molluscs further reveals the value of protected and conserved areas where mining is not approved.
Over 30 vent species worldwide are Least Concern thanks to living in Marine Protected Areas, such as Provanna exquisita, an ornate snail that lives only in the Mariana Arc of Fire National Wildlife Refuge in the Pacific Ocean, the IUCN underlined.
“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. Our new understanding of the impacts of deep-sea mining sheds light on a new frontier in science and conservation, providing important information as the International Seabed Authority meets in Jamaica this month,” said Julia Sigwart, member of the IUCN SSC Mollusc Specialist Group and Head of the Marine Zoology Department at Senckenberg Nature Research, the Red List Partner that coordinated these assessments in the statement.
Sigwart added that IUCN’s position is clear: in 2021, the Union voted for a moratorium on deep-sea mining unless all risks are understood and the marine environment is effectively protected.
“Life on Earth has adapted to survive in the most hostile and unusual habitats, such as deep-sea molluscs that live around extremely hot vents or the desert rain frog burrowing into the sand. Now as pressures on biodiversity mount across the planet, even the creatures with the most ingenious survival strategies are under threat,” said Grethel Aguilar, IUCN Director General.
On a positive note, in Australia, the numbat has improved its status thanks to decades of conservation action, although its survival depends on continued efforts.
The IUCN said the status of the numbat (Myrmecobius fasciatus) — the faunal emblem of Western Australia — has improved from Endangered to Near Threatened on the IUCN Red List. The numbat was widespread across southern Australia until the introduction and spread of cats (Felis catus) and red foxes (Vulpes vulpes), its numbers shrinking to around 300 animals by the late 1970s.
However, conservation work and effort on reducing the impact of feral cats and foxes via baiting and predator-proof fencing and captive breeding of numbat at Perth Zoo and translocations have led to the establishment of at least five more self-sustaining populations.
There are now between 2,000 and 3,000 numbats. However, the species occupies just 0.04 per cent of its original range, and as feral cats and foxes remain a major threat, ongoing management is essential to the numbat’s survival and recovery, the IUCN observed.
Besides, five Australian marsupials, newly recognised as a result of taxonomic review, have been confirmed as Extinct on the IUCN Red List.
They are identified as — little bettong (Bettongia haoucharae) and crested-tailed, southern, northern and little mulgaras (Dasycercus cristicauda, D. archeri, D. woolleyae and D. marlowi), with no individuals reported for at least 60 years.
“This brings the total number of modern mammal extinctions in Australia to more than 40. Predation by feral cats and foxes is the leading cause for their decline, with climate change a growing threat to those remaining,” the IUCN said.
John Woinarski, Co-Chair of the IUCN SSC Australasian Marsupial and Monotreme Specialist Group in the statement said, “Long-term, strategic and collaborative conservation effort works; without it, invasive cats and foxes will continue to drive Australia’s small marsupials and native rodents to extinction. Continued management is vital not only to maintain the numbat’s unique evolutionary line as the last surviving member of the Myrmecobiidae family, but also to support its role in maintaining a healthy ecosystem, as digging for the termites it eats increases rain penetration into the soil, helping protect woodlands.”
Meanwhile, diamond mining and energy infrastructure developments along the west coast of South Africa and Namibia have caused the desert rain frog (Breviceps macrops) to move from Near Threatened to Vulnerable on the IUCN Red List.
“Expanding industrial developments, which include a green hydrogen project, are expected to impact up to one-third of the desert rain frog’s range in South Africa and two-thirds in Namibia within the next 20 years,” the IUCN said.
It noted that suspected demand for the desert rain frog has increased in the pet trade has increased following a viral video of the species calling in distress.
“Climate change and associated heat stress and aridification are possible further strains on this species. Without conservation action, the population is expected to decline by 20 per cent in the next decade,” it added.