Scientists have completed the first study of microbes that live within the plumbing of deep-sea mud volcanoes in the Gulf of Mexico, where conditions may resemble those in extraterrestrial environments and early Earth. The study, which was partially funded by the National Science Foundation (NSF), was conducted in an area where clusters of seafloor vents spew mud, oil, brine and gases that support food chains independently of the Sun.
Specialized Microbes Thrive in Harsh Environments
A team lead by Samantha Joye of the University of Georgia managed to collect fluid samples from the crater of an active, bubbling mud volcano and from a brine pool that was previously a mud volcano. Brine pools are ponds of hyper-saline water that fill a seafloor depression without mixing with overlying seawater. These types of ecosystems--which have only rarely been studied by microbiologists or visited by anyone--are particularly hostile to much of life because they are devoid of light and oxygen, and are super-salty and bathed in noxious gases.
Nevertheless, researchers found that the mud volcano and the brine pool each support dynamic microbial communities. These microbial communities are not only distinct from each other but are also distinct from the microbial communities that live in the surrounding ocean. Results of the study, which appear in the April 6th issue of Nature Geosciences, have implications for life processes everywhere from early Earth to Mars to moons in our Solar System--such as Jupiter's Europa--where similarly extreme conditions may support microbiological life.
"Here we have more fascinating examples of microbial life coping with very, very unusual environments--regions of the ocean deeps that we can't help but describe as extreme or harsh," said Phillip Taylor, Head of NSF's Ocean Section. "Yet life has clearly adapted to exist, even thrive, in these systems. Such discoveries can't help but lead us to think that life beyond Earth is probable. Also, the discoveries of the evolved strategies for survival in unique environments have the potential to yield new uses of microbial processes and products in the biotech arena."
To reach the mud volcano and brine pool, Joye and her companions descended in a deep-sea research submersible to depths of 600 meters in the Gulf of Mexico. She describes her study sites, which are about 120 kilometers apart from one another, as feasts for the senses: "Near mud volcanoes, we saw thick plumes of gas bubbles ejected from boiling mud pots that are similar to those found in Yellowstone National Park. These gas plumes, consisting mainly of methane, extended hundreds of meters from the sea floor."
Bizarre phenomena abounded in the study area--from dancing eels that seemed to follow the window of the moving submersible, to a 50-foot wide volcano crater that was filled with a sulfur minerals and a reddish-colored microbial ooze. "These are the kind of scenes I imagine could exist on distant planets or other astronomical bodies," said Joye.
Adapting to Change
Conditions at mud volcanoes show tremendous short-term variation, with eruptions occurring daily to monthly to less frequently. What's more, the total lifespan of a mud volcano or brine pool is short by geologic standards--on the order of tens of thousands of years, rather than hundreds of thousands or millions of years.
After a mud volcano goes dormant, its craters and depressions persist on the sea floor and may then fill with high-salinity, high-density fluid that has ascended, along with oil and gas, from underlying salt domes, where the water was chemically altered; a brine pool is thereby formed.
The Joye team also found that the depth distribution and magnitude of key metabolic processes conducted by the microbial communities are unique to each type of geologic feature. "The diversity and distribution of the microbes we studied say a lot about how life adapts to extreme environments," said Joye. "We believe that the composition of the microbial communities and their metabolisms are linked to environmental differences, mainly in the geochemistry and intensity and frequency of fluid expulsion between the sites," said Joye.
Selection of the Study Sites
Thus far, only about five percent of the world's oceans have been explored. (By contrast, the dark side of the moon has been throughly mapped.)
Of all the world's unexplored marine environments, why did the Joye team choose to conduct their microbe study at the mud volcano and the brine pool? Because both environments are characterized by releases of gas and oil that are known to provide food and energy to microbes in deep, lightless environments where photosynthesis cannot occur. What's more, as Joye expected, the particularly harsh conditions created by the high-salinity of the brine pool selected for particularly well-adapted microbes that demonstrated distinct patterns of metabolic processes.
"The Joye team's study raises interesting and important questions," says Lita Proctor, an NSF Program Director. "For example, the Joye team's study has shown that these extreme environments can change rapidly. If these microbial communities are unique to each extreme environment, then how do the microbes that live in mud volcanoes reach and colonize these remote ecosystems in the first place or, for that matter, locate other mud volcanoes? Do they patiently wait in the ocean floor until a new mud volcano bursts through, or do they somehow migrate between mud volcanoes?"
These and other questions may be answered by future studies of these fascinating environments and help us understand how life on Early Earth may have evolved.
Lily Whiteman | EurekAlert!
Further reports about: > Brine pools > Earth's magnetic field > NSF > deep-sea mud volcanoes in > extraterrestrial environments > food chains > marine environment > metabolic process > microbial communities > microbiological life > primordial environments > reddish-colored microbial ooze > sea floor > seafloor depression > sulfur minerals > super-salty ecosystems
NASA's AIM observes early noctilucent ice clouds over Antarctica
05.12.2016 | NASA/Goddard Space Flight Center
GPM sees deadly tornadic storms moving through US Southeast
01.12.2016 | NASA/Goddard Space Flight Center
Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
05.12.2016 | Power and Electrical Engineering
05.12.2016 | Information Technology
05.12.2016 | Earth Sciences