Follow the crabs — Otherworldly mini-Yellowstone found in the deep sea We’ve known about deep ocean vents for a while, but it’s still hard to find them.
Ashley Balzer Vigil – Dec 28, 2023 1:14 pm UTC Enlarge / “Leading us like breadcrumbs…” A trail of squat lobsters helped researchers locate previously unknown hydrothermal vents. The hydrothermal vents create chemosynthetic ecosystems, so in areas that are mostly barren of life, the appearance of larger animals can be an indicator of vents nearby.Schmidt Ocean Institute reader comments 2
Spectacular scenery, from lush rainforests to towering mountain ranges, dots the surface of our planet. But some of Earths most iconic landmarksones that may harbor clues to the origin of life on Earth and possibly elsewherelay hidden at the bottom of the ocean. Scientists recently found one such treasure in Ecuadorian waters: a submerged mini Yellowstone called Sendero del Cangrejo.
This hazy alien realm simmers in the deep sea in an area called the Western Galpagos Spreading Centeran underwater mountain range where tectonic plates are slowly moving away from each other. Magma wells up from Earths mantle here to create new oceanic crust in a process that created the Galpagos Islands and smaller underwater features, like hydrothermal vents. These vents, which pump heated, mineral-rich water into the ocean in billowing plumes, may offer clues to the origin of life on Earth. Studying Earths hydrothermal vents could also offer a gateway to finding life, or at least its building blocks, on other worlds.
The newly discovered Sendero del Cangrejo contains a chain of hydrothermal vents that spans nearly two football fields. It hosts hot springs and geyser chimneys that support an array of creatures, from giant, spaghetti-like tube worms to alabaster Galatheid crabs.
The crabs, also known as squat lobsters, helped guide researchers to Sendero del Cangrejo. Ecuadorian observers chose the sites name, which translates to Trail of the Crabs, in their honor.
It did feel like the squat lobsters were leading us like breadcrumbs, like we were Hansel and Gretel, to the actual vent site, said Hayley Drennon, a senior research assistant at Columbia Universitys Lamont-Doherty Earth Observatory, who participated in the expedition. Enlarge / The Iguanas Vent Field, where the team did some sampling.Schmidt Ocean Institute
The joint American and Ecuadorian research team set sail aboard the Schmidt Ocean Institutes Falkor (too) research vessel in mid-August in search of new hydrothermal vents. They did some mapping and sampling on the way to their target location, about 300 miles off the west coast of the Galpagos.
The team used a Tow-Yo technique to gather and transmit real-time data to the crew aboard the ship. We lowered sensors attached to a long wire to the seafloor, and then towed the wire up and down like a yo-yo, explained Roxanne Beinart, an associate professor at the University of Rhode Island and the expeditions chief scientist. This process allowed us to monitor changes in temperature, water clarity, and chemical composition to help pinpoint potential hydrothermal vent locations. Advertisement Collecting samples in hellish conditions
The Schmidt Ocean Institute’s ROV SuBastian is designed to withstand the crushing pressure, high acidity, and scorching heat and extreme cold found near hydrothermal vents. SuBastian has lights and cameras to help a pilot on a ship at the surface guide it along. The ROVs titanium robot arms are both strong and resistant to corrosion. But collecting samples is still tricky.
Rocks and organisms in the deep sea have adapted to conditions we consider extreme. So, to them, the surface environment is extreme. Transporting them to such a drastically different environment requires quick, precise handling and proper storage in insulated containers that maintain cold temperatures until they reach the surface, which preserves the integrity of the samples. Some containers, called isobaric gas-tight samplers, remove and store fluid samples at the pressures found on the ocean floor. These samples retain dissolved gasses as they are brought up to the surface, enabling scientists to study different elements and molecules in vent gasses. Those components could hold clues about activity that takes place beneath the seafloor.
When they reached a region that seemed promising, they deployed the remotely operated vehicle SuBastian for a better look. Less than 24 hours later, the team began seeing more and more Galatheid crabs, which they followed until they found the vents.
The crabs were particularly useful guides since the vent fluids there are clear, unlike black smokers that create easy-to-see plumes. SuBastian explored the area for about 43 hours straight in the robots longest dive to date.
But the true discovery process spanned decades. Researchers have known for nearly 20 years that the area was likely home to hydrothermal activity thanks to chemical signals measured in 2005. About a decade later, teams ventured out again and collected animal samples. Now, due to the Schmidt Ocean Institutes recent expedition, scientists have the most comprehensive data set ever for this location. It includes chemical, geological, and biological data, along with the first high-temperature water samples.
Its not uncommon for an actual discovery like this to take decades, said Jill McDermott, an associate professor at Lehigh University and the expeditions co-chief scientist. The ocean is a big place, and the locations are very remote, so it takes a lot of time and logistics to get out to them. The team will continue their research onshore to help us understand how hydrothermal vents influence our planet. Genesis from hell?
Sendero del Cangrejo may compare to a small-scale Yellowstone in some ways, but its no tourist destination. Its pitch-black since sunlight cant reach the deep ocean floor. The crushing weight of a mile of water presses down from overhead. And the vents are hot and toxic. Some of them clocked in at 290 C (550 F)nearly hot enough to melt lead.
Before scientists discovered hydrothermal vents in 1977, they assumed such extreme conditions would preclude the possibility of life. Yet that trailblazing team saw multiple species thriving, including white clams that guided them to the vents the same way the Galatheid crabs led the modern researchers to Sendero del Cangrejo. A series of seafloor photos shows the sudden appearance of live white clams that led scientists to find hydrothermal vents for the first time. WHOI Archives
Before the 1977 find, no one knew life could survive in such a hostile place. Now, scientists know there are microbes called thermophiles that can only live in high temperatures (up to about 120 C, or 250 F).
Bacteria that surround hydrothermal vents dont eat other organisms or create energy from sunlight like plants do. Instead, they produce energy using chemicals like methane or hydrogen sulfide that emanate from the vents. This process, called chemosynthesis, was first identified through the characterization of organisms discovered at these vents. Chemosynthetic bacteria are the backbone of hydrothermal vent ecosystems, serving as a nutrition source for higher organisms. Advertisement
Some researchers suggest life on Earth may have originated near hydrothermal vents due to their unique chemical and energy-rich conditions. While the proposal remains unproven, the discovery of chemosynthesis opened our eyes to new places that could host life.
The possibility of chemosynthetic creatures diminishes the significance of so-called habitable zones around stars, which describe the orbital distances between which surface water can remain liquid on a planet or moon. The habitable zone in our own Solar Sysem extends from about Venus orbit out nearly to Mars.
NASAs Europa Clipper mission is set to launch late next year to determine whether there are places below the surface of Jupiters icy moon, Europa, that could support life. Its a lot colder out there, well beyond our Solar Systems habitable zone, but scientists think Europa is internally heated. It experiences strong tidal forces from Jupiters gravity, which could create hydrothermal activity on the moons ocean floor.
Several other moons in our Solar System also host subsurface oceans and experience the same tidal heating that could potentially create habitable conditions. By exploring Earths hydrothermal vents, scientists could learn more about what to look for in similar environments elsewhere in our Solar System. The Oceans Multivitamin
While hydrothermal vents are relatively new to science, theyre certainly not new to our planet. Vents have been active since Earths oceans first formed, McDermott said. Theyve been present in our oceans for as long as weve had them, so about 3 billion years.
During that time, theyve likely transformed our planets chemistry and geology by cycling chemicals and minerals from Earths crust throughout the ocean.
“All living things on Earth need minerals and elements that they get from the crust, said Peter Girguis, a professor at Harvard University, who participated in the expedition. Its no exaggeration to say that all life on earth is inextricably tied to the rocks upon which we live and the geological processes occurring deep inside the planetits like the oceans multivitamin.
But the full extent of the impact hydrothermal vents have on the planet remains unknown. In the nearly 50 years since hydrothermal vents were first discovered, scientists have uncovered hundreds more spread around the globe. Yet no one knows how many remain unidentified; there are likely thousands more vents hidden in the deep. Detailed studies, like those the expedition scientists are continuing onshore, could help us understand how hydrothermal activity influences the ocean. Enlarge / ROV SuBastian takes water and chemical samples from a black smoker hydrothermal vent in the Iguanas Vent Field, Galapagos Islands.Schmidt Ocean Institute
The teams immediate observations offer a good starting point for their continued scientific sleuthing.
I actually expected to find denser animal populations in some places, Beinart said.
McDermott thinks that could be linked to the composition of the vent fluids. Several of the vents were clearnot very particle-rich, she said. Theyre probably lower in minerals, but were not sure why. Now, the team will measure different metal levels in water samples from the vent fluids to figure out why theyre low in minerals and whether that has influenced the animals the vents host.
Researchers are learning more about hydrothermal vents every day, but many mysteries remain, such as the eventual influence ocean acidification could have on vents. As they seek answers, theyre sure to find more questions and open up new avenues of scientific exploration.
Ashley writes about space as a contractor for NASA’s Goddard Space Flight Center by day and freelances as an environmental writer. She holds a master’s degree in space studies from the University of North Dakota and is finishing a master’s in science writing through The Johns Hopkins University. She writes most of her articles with one of her toddlers on her lap. reader comments 2 Advertisement Channel Ars Technica ← Previous story Related Stories Today on Ars
