Deep-Sea Snail Builds Its Own Ironclad Suit of Armor. But Even That Can’t Protect It From Ocean Mining

The sea pangolin only lives by a few hydrothermal vents in the Indian Ocean, which are being targeted by deep-sea miners

Iron Snail
Julia Sigwart/The Conversation

Lots of species are added to the International Union for the Conservation of Nature’s Red List, the international endangered species list, each year. But the addition of a strange little deep-sea scaly foot snail called the sea pangolin (Chrysomallon squamiferum) is the first time a creature has been declared endangered due to the threat of deep sea mining, a technology that has yet to be fully developed.

Matt Simon at Wired reports that the snail is known from just four hydrothermal vents in the Indian Ocean. They are tough neighborhoods—about 1.5 miles underwater with crushing pressures and temperatures up to 750 degrees Fahrenheit. but the sea pangolin has developed an awesome way of coping. It builds the outer layer of its shell with iron sulfide, creating a suit of armor around its squishy, snaily innards. Researchers also believe the snail doesn’t really eat anything, but instead it relies on energy produced from bacteria it hosts in a large gland. In other words, it is a truly peculiar, confusing creature.

It's also very rare. Marine Biologist Julia Sigwart, who studies the snail at Queen’s University in Belfast, is one of the researchers who petitioned to have it classified as endangered on the IUCN's Red List. She writes at The Conversation the creature’s total habitat, even including undiscovered colonies, maxes out at about 0.1 square miles. While it may seem like protecting such a tiny slice of ocean floor would be easy, it’s not.

Jonathan Lambert at Nature reports that two of the vents where the snails live have active mining exploration licenses on them. Even one session of exploratory drilling could have an impact on the snail population and other rare and sensitive creatures living near these vents. That’s why Sigwart and other specialists campaigned to have the species protected.

“This is an important step towards alerting policymakers to the potential impacts deep-sea mining may have on biodiversity,” Lisa Levin, a biologist at the Scripps Institution of Oceanography, tells Lambert.

Mining of the sea floor, and especially mining at the depths where the snails live is not yet technologically or economically viable. But mining companies are gearing up for the day in the near future when they will be able to begin extracting metals and minerals from the deep. Deep sea hydrothermal vents, like the ones where the sea pangolin lives, are especially attractive since hydrothermal processes can concentrate gold, zinc, cobalt, and lithium in areas around the vents.

Besides the vents, mining ventures also have their eye on a vast swath of the ocean floor littered with “polymetallic nodules,” or rocks made up of things like copper, nickel and manganese. Currently, about 500,000 square miles of seafloor have been contracted for mining exploration. Later this summer, miners will begin testing a prototype nodule collector in the Mediterranean.

Researchers are raising the alarm with the International Seabed Authority (ISA), a United Nations agency which manages the seafloor in international waters. Mining won’t be able to get underway before the ISA finalizes its code of conduct, which is expected to happen in 2020. It’s not clear how the presence of sensitive ecosystems or endangered species will be treated by those rules. That’s one reason scientists pushed for the sea pangolin’s listing now, to raise awareness that these habitats are being threatened. Twenty-eight ocean scientists recently sent an open letter to the ISA raising their concerns. The endangered listing for the sea pangolin—besides attempting to protect the species—is an attempt to raise awareness with the public and policy makers. “Being on that list means something to policymakers and ordinary people,” Chong Chen, a deep-sea biologist at the Japan Agency for Marine-Earth Science and Technology in Yokosuka tells, Lambert.

Sigwart says that marine biologists are now assessing the status of other deep-ocean creatures living at hydrothermal vent habitats throughout the world. “Endangered status for hydrothermal vent species only found in areas under license for mining exploration, could be compared to a species that only lives in a patch of rainforest scheduled for logging,” Sigwart writes at The Conversation.

The hope is that the ISA will protect sensitive areas and even make active hydrothermal vents off limits to mining. The unique habitat in which they live means deep-sea creatures, even those with suits of iron, are particularly vulnerable.

“These are fragile areas under threat, and it’s not like we researchers can start a breeding program for deep-sea-vent creatures,” Sigwart tells Lambert. “We can only try to protect what’s there.”

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