A large cluster of tubeworms at Fava Flow Suburbs, a site on the East Pacific Rise 2,500 meters deep.
Experiments testing the theory of species dispersal through cracks in Earth's crust were performed in this area.
Experiments testing the theory of species dispersal through cracks in Earth's crust were performed in this area.
Credit: ROV SuBastian/Schmidt Ocean Institute (CC BY-NC-SA 4.0)
From Scientific America by Jack Tamisiea
An expedition using a deep-sea remotely operated vehicle has uncovered a hidden underground ecosystem below hydrothermal vents on the seafloor
There may be no ecosystem on Earth that seems less hospitable than hydrothermal vents.
In the perpetual darkness, cold and relentless pressures of the deep sea, these volcanic seeps spew piping hot water so loaded with particles and metals that it looks like black smoke billowing from a chimney.
But even these hellish habitats are crawling with life, ranging from giant clams and ravenous crabs to spindly octopuses and ghostly eelpout fish.
Schmidt Ocean Institute's research vessel Falkor (too) sets sail on 3rd March, on a 40-day mission to uncover unknown vents and lifeforms along the mid-Atlantic ridge.
Using state-of-the-art laboratories, the team hope to capture images of undiscovered life at the depths of the ocean.
And those are just the creatures lurking above the vents.
Using a deep-sea remotely operated vehicle (ROV), researchers recently flipped over slabs of seafloor to uncover a hidden ecosystem teeming with tiny life beneath the vents themselves.
According to Monika Bright, a zoologist at the University of Vienna, who led the expedition, the assortment of worms, snails and microscopic larvae and bacteria that reside down here adds a new layer of complexity to hydrothermal vent ecosystems, which scientists have studied since 1977.
“We’ve known about the vents above for a long time, but this is basically a completely new ecosystem below,” Bright says.
“It’s especially strange that we found it in a place that is very well studied.”
Last month Bright and an international team of collaborators boarded the nonprofit Schmidt Ocean Institute’s research vessel Falkor (too) in Panama.
The scientists plumbed the depths off Central America’s Pacific coast to study species ranging from symbiotic bacteria in deep-sea clams to the temperature limits of tiny copepod crustaceans.
Using a deep-sea remotely operated vehicle (ROV), researchers recently flipped over slabs of seafloor to uncover a hidden ecosystem teeming with tiny life beneath the vents themselves.
According to Monika Bright, a zoologist at the University of Vienna, who led the expedition, the assortment of worms, snails and microscopic larvae and bacteria that reside down here adds a new layer of complexity to hydrothermal vent ecosystems, which scientists have studied since 1977.
“We’ve known about the vents above for a long time, but this is basically a completely new ecosystem below,” Bright says.
“It’s especially strange that we found it in a place that is very well studied.”
Last month Bright and an international team of collaborators boarded the nonprofit Schmidt Ocean Institute’s research vessel Falkor (too) in Panama.
The scientists plumbed the depths off Central America’s Pacific coast to study species ranging from symbiotic bacteria in deep-sea clams to the temperature limits of tiny copepod crustaceans.
Superheated fluid streams past tubeworms and other creatures that dwell around hydrothermal vents on the East Pacific Rise.Credit: ROV SuBastian/Schmidt Ocean Institute (CC BY-NC-SA 4.0)
The team focused its ROV dives on an area where diverging tectonic plates create a string of deep-sea volcanoes known as the East Pacific Rise.
As the plates drift apart, magma bubbles up from the rift and cools to create new oceanic floor.
These volatile conditions fuel hydrothermal vents.
Frigid water percolates through fissures in the splintering oceanic crust and meets the scalding magma below.
When the seawater is heated to temperatures of more than 400 degrees Celsius, chemical reactions create a supercharged fluid that is rich in chemicals such as sulfur, and it spews out of openings in the ocean floor.
These geyserlike vents are hotspots of deep-sea diversity that can thrive in the dark, thanks to bacteria that convert chemicals into energy-providing sugars.
Some of these bacteria reside inside the elongated bodies of giant tubeworms (Riftia pachyptila).
These worms, whose exposed bright-red, feathery gills make them look like six-foot-long lipstick tubes, grow in dense patches around the vents and provide habitats for other vent dwellers.
When eruptions or earthquakes alter the area’s volcanic activity, these strongholds of hardy worms are wiped out.
But when new hydrothermal vents pop up dozens or even hundreds of kilometers away, they are quickly colonized by towering thickets of giant tubeworms within a few years.
Just how these worms arrive and anchor themselves at new vents remains unknown, Bright says.
Scientists have found few tubeworm larvae in the water column surrounding vents, and constant stream of supercharged fluid would also make it difficult for the larvae to attach themselves from above.
This led the researchers to hypothesize that tubeworm larvae were squirming through crevices below the seafloor to reach new vents.
"We do not fully understand how the animals who live on hydrothermal vents find them and come to the vents."
The #VentUnderworld team has embarked on an expedition to determine how animals are transported to hydrothermal vents and build communities.
The team suspects that the answer does not solely lie in the waters above the vents but also in the hydrothermal fluid circulating in the earth's crust.
They have created a new piece of equipment, called a Mesh Box Staining Gadget, to determine if life is traveling through earth's crevices to form ecosystems on hydrothermal vents.
"We need to know the connectivity between the different habitats, the different environments. The more we know about everything, the more we can also protect it."
Expedition: FKt230628 - The Underworld of Hydrothermal Vents - Week 1
Working as part of a team on Research Vessel Falkor (too) creates a situation ripe for the spreading of knowledge and cross-collaboration.
Scientists are close to - and may work on - projects that are not in their precise field of expertise. "Through doing that, you learn a lot about sort of different methods that people use and learn from: not only the hard skills of science, but also the soft skills of the creativity, the precision, the attention to detail."
The team has been conducting experiments, gathering samples, and measuring data around hydrothermal vents, making tremendous strides in gaining knowledge about these areas.
The teamwork happening on board is key to success: "I think this is something special about going on expeditions [at sea], because everyone is interested in different aspects of the deep sea, and then you get to know a lot about the whole ecosystem, not only your specific subject."
While conducting their seafloor experiments, the #VentUnderworld team encountered fantastical creatures from the Ocean's surface down the seafloor.
Pelagic rays, thresher sharks, oceanic white tip sharks, phantom jellyfish, larvaceans, and the charismatic glass octopus are just some examples.
On the seafloor, SOI's stellar ROV pilots aided the scientists in deploying and adhering new scientific equipment known as "Mesh Box Staining Gadgets."
These experiments were intended to collect data on whether or not hydrothermal vent animals are traveling through the vent systems below Earth's surface.
Expedition: FKt230729 - The Underworld of Hydrothermal Vents - 4K ROV Highlight Reel
To test this idea, the scientists sent the ROV down to the Tica Vent, a well-studied hydrothermal vent located 2,500 meters below the ocean’s surface.
Initially, the team glued mesh boxes over cracks in the seafloor to collect animals that moved between the rocky floor itself and the subsurface below.
But when the boxes proved cumbersome, the team employed a more direct method: flipping over heavy chunks of seafloor with the ROV’s robotic arm to collect what lay beneath.
This uncovered an underworld labyrinth.
In a network of caves and crevices carved through the rock, the water was a balmy 25 degrees C.
This provided the perfect conditions for a thriving microbial community of protists, bacteria, viruses and even some larger creatures such as snails and worms.
While the team is the first to peer below the seafloor around these hydrothermal events, its discovery is not entirely surprising to Julie Huber, a geochemist at the Woods Hole Oceanographic Institution, who was not involved in the expedition.
She notes that the oceanic crust along mid-ocean ridges is porous, offering plenty of real estate for fluids, nutrients and microbes.
“Given most of the animals at hydrothermal vents require all three of these things to thrive, I suppose it makes sense that animals are carving out another niche to attach themselves to and make a living,” Huber says.
She also thinks residing below the seafloor may help keep these tiny critters safe from prowling deep-sea crabs.
Initially, the team glued mesh boxes over cracks in the seafloor to collect animals that moved between the rocky floor itself and the subsurface below.
But when the boxes proved cumbersome, the team employed a more direct method: flipping over heavy chunks of seafloor with the ROV’s robotic arm to collect what lay beneath.
This uncovered an underworld labyrinth.
In a network of caves and crevices carved through the rock, the water was a balmy 25 degrees C.
This provided the perfect conditions for a thriving microbial community of protists, bacteria, viruses and even some larger creatures such as snails and worms.
While the team is the first to peer below the seafloor around these hydrothermal events, its discovery is not entirely surprising to Julie Huber, a geochemist at the Woods Hole Oceanographic Institution, who was not involved in the expedition.
She notes that the oceanic crust along mid-ocean ridges is porous, offering plenty of real estate for fluids, nutrients and microbes.
“Given most of the animals at hydrothermal vents require all three of these things to thrive, I suppose it makes sense that animals are carving out another niche to attach themselves to and make a living,” Huber says.
She also thinks residing below the seafloor may help keep these tiny critters safe from prowling deep-sea crabs.
A rock crust sample, flipped upside down, reveals Oasisia and Riftia tubeworms, as well as other organisms.
Credit: ROV SuBastian/Schmidt Ocean Institute (CC BY-NC-SA 4.0)Below the vents, the researchers also discovered a lot of tiny tubes, which revealed that these subsurface chambers serve as tubeworm nurseries.
The scientists posit that tubeworm larvae traverse this subsurface maze, which Huber refers to as the “subseafloor conveyor belt,” to travel from vent to vent.
The tubeworms initially live down there before moving up toward the vents as they grow as much as 85 centimeters per year.
Many mysteries remain about the realm below hydrothermal vents, however.
Bright and her colleagues plan to sequence the genetics of animals and microbes collected both above and below the seafloor to examine how these two ecosystems are connected.
“As a scientist, you find out something, and then there [are] 10 more questions you have,” Bright says.
Bright and her colleagues hope that shedding more light on the inner workings of hydrothermal vent ecosystems will help shield them from development.
These areas are of potential interest to deep-sea mining companies because of the minerals that leach out of the magma-heated water as it gushes out of the vents.
That economic incentive could endanger one of the planet’s most unique environments, a realm that Bright says scientists still struggle to comprehend.
“From our view these vents are very extreme and exotic,” she says.
“But for the animals, it’s not extreme to live at these pressures with fluctuating temperatures and fluctuating chemistry—it’s normal.”
The scientists posit that tubeworm larvae traverse this subsurface maze, which Huber refers to as the “subseafloor conveyor belt,” to travel from vent to vent.
The tubeworms initially live down there before moving up toward the vents as they grow as much as 85 centimeters per year.
Many mysteries remain about the realm below hydrothermal vents, however.
Bright and her colleagues plan to sequence the genetics of animals and microbes collected both above and below the seafloor to examine how these two ecosystems are connected.
“As a scientist, you find out something, and then there [are] 10 more questions you have,” Bright says.
Bright and her colleagues hope that shedding more light on the inner workings of hydrothermal vent ecosystems will help shield them from development.
These areas are of potential interest to deep-sea mining companies because of the minerals that leach out of the magma-heated water as it gushes out of the vents.
That economic incentive could endanger one of the planet’s most unique environments, a realm that Bright says scientists still struggle to comprehend.
“From our view these vents are very extreme and exotic,” she says.
“But for the animals, it’s not extreme to live at these pressures with fluctuating temperatures and fluctuating chemistry—it’s normal.”
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