Into the Abyss

• Mid-Oceanic Ridges

• Hydrothermal Communities

• Vent Bio-Chemistry

• Hypotheses about Life's Origins

• Current Research

• Links

Inner Space ... The Final Frontier ... ta da These are the voyages of the deep sea vehicle "Alvin" whose five year mission is to explore strange, new worlds... ta dum (with apologies to Star Trek)

The deep ocean floor was long thought to be a relatively sterile environment, inhabited at best by only scavenger lifeforms that led a minimalistic subsistence feeding off the organic detritus coming from the thriving "organic" layer. With sunlight unable to penetrate much past 300 feet of water, it seemed obviously that this set the limits on any kind of dynamic foodweb, long assumed to be based on photosynthesis. This fit well with our other notions of the "abyss" - static and unchanging.

Deep Sea Vehicle "Alvin"

Into the Abyss
-- Nova Online Adventure

Mid-Oceanic Ridges

The active spreading centers are along the mid-oceanic ridges, where the magma, at
temperatures over 1,000 °C, is erupting to form new oceanic crust.

In 1977, scientists discovered hot springs at a depth of 2.5 km at a ridge off the coast of South America. Since that time, numerous hydrothermal sites have been discovered at the bottom of the ocean. These are also referred to as geothermal vents - or smokers.

Geothermal Vents
What happens here is that due to plate shifting, there are fissures that open up in the earth's surface. The ambient bottom water is sucked down into the cracks and goes down toward the center of the earth and comes in contact with the hot molten magma at the center of the earth, is superheated and then is forcibly discharged back into the environment through the ocean floor.

from Life with toxic hydrogen sulfide
- Access Excellence (Genentech, Inc., sole sponsor), national educational program for biology, 7/30/97

American Museum of Natural History: Black Smokers
"... scientists are attempting to collect a black smoker to bring back to their laboratories for further investigation ... Once the research is complete the black smoker structure that is collected will eventually be on display in The Hall of Planet Earth at the American Museum of Natural History due to open in 1999."
-- American Museum of Natural History

Hydrothermal Communities

A Host of Animals
... a great deal of biological life ... pillow lava here in the foreground, sort of a rocky substrate and clams that are wedged into the fissures between the pillow lava. As you get in closer to the vent proper, there are tubeworms, there are white smoker chimneys and black smoker chimnies with the hot water percolating out and a lot of free ranging animals roaming in and out of the vent environment, Brachyuran crabs, Galatheid crabs, several species of fish and a host of other animals.

One of the most dramatic and most well known of the animals from the hydrothermal vent environment is the giant tubeworm. This is Riftia pachyptila. Riftia, named after rift. Colonies of Riftia group together around effluent points in the hydrothermal vent. In other words, they are growing right in the water that is percolating out from the sea floor.

The Food Chain at the Vent
... what was going on ...with the basis of the food chain, the source of the energy to power the biology at this remote location. Prior to the discovery of the hydrothermal vents, most biologists believed that all life depended upon the energy of sunlight. That is, the basis of the food chain was photic energy which powered photosynthesis, obviously in green plants that went down the chain with animals eating plants, and animals eating animals. When the hydrothermal vents were discovered, it was clear very rapidly that they were a very enriched biological environment, very, very remote from the surface sunlight. It was difficult to imagine that energy could basically drift down in high enough quantities to nurture this environment.

Other interesting data that came to mind, or that came to be known, were that most of the animals here, the large invertebrates, basically had no digestive system. The large tubeworm, Riftia, has no mouth, no gut, no anus. However, it is a huge animal - they're about a 1.5 M in length and up to 2 cm in diameter and there are many, many of them in these hydrothermal vent sites. So the question was, how are they managing to make a living down there?

... were harboring bacteria within their body cavities. Now bacteria, free living bacteria, in this environment and in our own backyard, have been known for years to be able to use chemical energy as a basis of their metabolism. So in the case of the free living bacteria, there are many sulfide oxidizing bacteria which can use chemical sulfide to basically run their metabolic pathways - to produce organic compounds, small nutrient compounds, that form the basis of their nutrition. What is happening in some of the hydrothermal vent animals is that they are harboring these chemical utilizing bacteria, within their body tissues. So for instance the large tubeworm, Riftia, and the clam, Caliptogena, harbored dense aggregations of bacteria, either in what was the residual gut of the tubeworm or in the gill area for the clam. These bacteria then are able to utilize the inorganic chemicals in the environment. They utilize hydrogen sulfide. What they do with the hydrogen sulfide is analogous to what plants do with photic energy. So it is called chemosynthesis rather than photosynthesis.

This was a fairly fundamental discovery, because this was the first very well defined ecosystem, and very elaborate ecosystem, that was completely independent of sunlight at any level of the food chain.

from Life with toxic hydrogen sulfide
- Access Excellence (Genentech, Inc., sole sponsor), national educational program for biology, 7/30/97

Hydrothermal Vent Communities
"... hydrogen sulphide is the basis of the hydrothermal vent community, providing essential nutrients for chemosynthetic bacteria that use the hydrogen sulphide as a source of energy. These bacteria do not need sunlight to produce energy, which is how they are able to live and grow in the ocean depths ... The bacteria themselves are a food source for a variety of creatures"
-- Northern New South Wales marine ecosystems

Bio-chemistry at the Vents

Chemosynthesis
What is happening is that hydrogen sulfide is oxidized, so oxygen is necessary for this process, and the energy released from this oxidation of this hydrogen sulfide molecule is used to power, the fixation of carbon dioxide into small organic compounds. So this cycle ... is the same metabolic pathway that is utilized by plants in photosynthesis ... takes inorganic carbon dioxide and fixes it into organic compounds that are then food. But, the difference here, the critical difference, is that rather than using sunlight, these animals and bacteria are completely independent of sunlight. They utilize chemical energy to power that reaction.

from Life with toxic hydrogen sulfide
- Access Excellence (Genentech, Inc., sole sponsor), national educational program for biology, 7/30/97

Thermostable Proteins
The organism is the first thermophilic bacterium sequenced ... Theromophilic bacteria love heat, not minding in the least temperatures as high as 95 degrees Centigrade (203 degrees Fahrenheit) ... Each of the 1,500 newly identified genes encodes for thermostable proteins ... the scientists may uncover the genetic origins of Earth’s first bacterium ...

The genomes of bacteria such as these hold great interest for evolutionary biologists seeking insight into the earliest life on Earth. It is hypothesized that life originated in a high-heat, low-oxygen environment like that most suited to A. aeolicus ...

from Bacteria DNA Unraveled
-- ABCnews.com, 3/25/98

Prokaryote vs. Eukaryote
Certain simple, "prokaryotic" organisms grow at temperatures above 235.4 degrees Fahrenheit (113°C), Cary says, but such high heat kills eukaryotes. "The nuclear and mitochondrial membranes in more complex organisms were thought to be their Achilles heel," he explains. "When those membranes melt, it's curtains for the eukaryote."

from Scientists getting to know heat-tolerant worms
-- Environmental News Network, 2/9/98

Membrane Protection
Higher body temperatures, he points out, require special saturated lipids in the membranes that don't melt at high temperatures. To survive, Somero says, the worm may have this sort of lipid in its tail and another low-temperature version in its head. Carey hopes the worms--and the bacteria that coat their backs--might also provide a storehouse of new enzymes that work at a wide range of temperatures.

from Warrior Worms
-- American Association for the Advancement of Science News Service, 2/4/98

Hydrothermal Vent Geochemistry
-- National Oceanic and Atmospheric Administration

Hypotheses about Life's Origins

And so what they realized is that photosynthesis was not the only way to support life. We could say that this discovery stretches our concept of the origin of life on our own planet. Because these deep sea hydrothermal vents could be the most ancient sites of life on Earth.

Oceans have existed, more or less, since the beginning of Earth's history. Life on the bottom of the oceans is actually well protected from variability on the surface of the Earth. This environment is insulated by the oceans and very, very old. And so for that reason, it's a good candidate for the origin of life.

from Deep Sea Vents -- Origin of Life?
-- Pulse of the Planet, American Museum of Natural History

Chemical of life, ammonia, produced at vents
... report that one of the necessary first steps for life to begin the conversion of nitrogen to ammonia may have occurred readily in deep ocean vents. Nitrogen is an essential ingredient of amino acids and nucleic acids. But molecular nitrogen, N2, is relatively inert and unlikely to have given rise to the first vital signs of life. Most scientists believe instead that nitrogen in a more reduced, reactive form, i.e., ammonia, or NH3, was required. How did nitrogen, then, become ammonia?

... that the most likely sites for ammonia production to occur were in the early Earth's crust and in hydrothermal vents, where iron-bearing minerals act as catalysts.

Using iron sulfides, they found that at 500C, up to 89% of the nitrogen converted to NH3 within 15 minutes! Iron oxide converted up to 46% of the nitrogen to ammonia, while powdered basalt converted up to 20% under these conditions. Reduction of N2, the largest reservoir of nitrogen on Earth, was slower but still resulted in up to 17% conversion to ammonia within 24 hours. The ammonia is stable, they found, to temperatures up to 800C, but only nitrogen gas survives temperatures above that temperature. Thus, N2 or its oxidized forms would have provided raw materials for an important and plentiful source of ammonia in the ancient oceans, perhaps providing oases of NH3 for the production of amino acids and nucleic acids in early life forms.

from Key chemical in life creation - ammonia - created at hydrothermal vents
-- exosci.com, 10/23/98

Life Origins from Undersea Volcano
"Life probably started at similar hot springs as a way of speeding up the reaction of hydrogen with carbon dioxide in ancient ocean water.”
-- ABCnews.com, 10/9/98

Current Research

Researchers from NASA's Jet Propulsion Laboratory are conducting these first-time engineering tests at the California aquarium as a precursor to an experiment that will place a scientific probe in an underwater Hawaiian volcanic vent later this year. The Lo'ihi Underwater Volcanic Vent Mission Probe will investigate an undersea volcano located 27 kilometers (20 miles) east of the Big Island of Hawaii at a depth of about 1,300 meters (4,250 feet).

from Aquarium test helps scientists look for life in extreme environments
-- JPL, 8/20/98

New Millennium Observatory at Axial Volcano
The NeMO 1998 expedition left aboard the NOAA research ship Ronald H. Brown Aug. 24 and returned Sept. 20. The ship was loaded with a multitude of sampling, sensing and photographic instruments, some of which are being left behind at the summit of the Axial Volcano, 240 miles off the coast of Oregon, to continue their work for the next year. The Canadian-built remote operating vehicle known as ROPOS -- Remotely Operated Platform for Ocean Science -- was also on board, destined to take more than 20 unmanned dives in the pursuit of science.

... the beginning of a totally unique, long-term, unmanned observatory on the sea floor ... 'NeMO,' short for New Millennium Observatory ... NeMO will make it possible to begin understanding relationships between volcanic and hydrothermal hot springs and the microbial biosphere which lies beneath the volcano's surface.

from Sea floor observatory set up at volcano
-- CNN.com, 10/21/98

Links

Deep Sea Vents -- Origin of Life?
"Scientists have long suspected that life on Earth originated in the ocean and strong evidence now suggests that the earliest life on our planet occurred in the depths of the ocean in the absence of heat and light."
-- Pulse of the Planet, American Museum of Natural History

Deep Sea Vents -- Underwater Geysers
"For the past 25 years, scientists have been investigating hot water vents which occur along the ridges that cross the ocean floor. These hydrothermal vents are marked by dramatic plumes of black or white water which look like clouds of smoke. "
-- Pulse of the Planet, American Museum of Natural History

Deep Sea Vents -- Inside Alvin
"For scientists investigating the ocean floor, doing their field work means climbing into a submarine and going where few humans have gone before. "
-- Pulse of the Planet, American Museum of Natural History

Life with toxic hydrogen sulfide
"The interesting thing about hydrogen sulfide, biologically, is that it is a highly toxic molecule. It is toxic on the same level as cyanide ... There are a number of animals that are tolerant of sulfide and can live in sulfide rich environments ... strategies that could be employed for the tolerance of sulfide"
- Access Excellence (Genentech, Inc., sole sponsor), national educational program for biology, 7/30/97

Hydrothermal Vent Geochemistry
"Seafloor hydrothermal systems have a major local impact on the chemistry of the ocean..."
-- National Oceanic and Atmospheric Administration

Warrior Worms
"Few creatures adapted to one extreme can survive long in the other, partly because most enzymes critical for life work only in a narrow temperature range. Now scientists have discovered that a worm at the bottom of the ocean shatters all endurance records."
-- American Association for the Advancement of Science News Service, 2/4/98

Exploring the deep ocean floor [This Dynamic Earth]
"In 1977, scientists discovered hot springs at a depth of 2.5 km, on the Galapagos Rift (spreading ridge) off the coast of Ecuador ... More exciting, because it was totally unexpected, was the discovery of abundant and unusual sea life -- giant tube worms, huge clams, and mussels -- that thrived around the hot springs."
-- United States Geological Service, 9/9/97

"Studying hydrothermal vents... it's not like collecting postage stamps."
Example profile of researcher, with bibliography
-- Private website

Deep Sea Hydrothermal Vents
"Deep-sea hydrothermal vents form along mid-ocean ridges, the volcanic undersea mountain ranges where new seafloor is created ... The chemicals contained in the vent fluids support a thriving ecosystem on the ocean floor. This ecosystem is completely independent of the sun's energy."
-- University of Washington School of Oceanography Exploraquarium

Resources on Hydrothermal Vents
Links
-- Fisheries-Oceanography Library, University of Washington

American Museum of Natural History: Black Smokers
"... scientists are attempting to collect a black smoker to bring back to their laboratories for further investigation ... Once the research is complete the black smoker structure that is collected will eventually be on display in The Hall of Planet Earth at the American Museum of Natural History due to open in 1999."
-- American Museum of Natural History

Marine Science Information and Interaction
FAQ: Ecology - Oceanography - Hydrothermal Vents/Deep Sea Biology - Other
-- Oceanlink (British Columbia)

Ocean Floor
"Here we will examine the deep sea geography of this world's unexplored frontier. You will hopefully see some sea mountains, and hydrothermal vents ..."
-- Canadian Institute of Oceanography

Hydrothermal Vent Communities
"... hydrogen sulphide is the basis of the hydrothermal vent community, providing essential nutrients for chemosynthetic bacteria that use the hydrogen sulphide as a source of energy. These bacteria do not need sunlight to produce energy, which is how they are able to live and grow in the ocean depths ... The bacteria themselves are a food source for a variety of creatures"
-- Northern New South Wales marine ecosystems

Scientists getting to know heat-tolerant worms
"... the first report of a "eukaryotic metazoan" or higher-order life form capable of surviving sustained, long-term exposure to temperatures up to 176 degrees Fahrenheit."
-- Environmental News Network, 2/9/98

The Escanaba Trough of Gorda Ridge: A Laboratory for Mineral-forming Processes
"The Escanaba Trough provides opportunities for scientists to learn details about tectonics, volcanism, mineral formation, and biological activity that are not normally observed at mid-ocean ridges. It is a geological laboratory of grand proportions."
-- United States Geological Service,, 7/1/96

NASA site on hydrothermal vents
"Far from sunlight, sulfur supports strange life forms. In 1977 geologists exploring fractures in the ocean floor found more than they had anticipated. Large, odd-looking animals were surviving on the sunless, otherwise barren sea floor by what turned out to be an entirely unknown mode of life..."
-- NASA, SeaWiFS (global ocean color monitoring mission) & Ocean Planet

Deep-Sea Page
Life in the Deep - Research at Sea - High Pressure Deep Sea Animals - New Discoveries - Other
-- Private website

Deep-sea scientists explore origins of life
"At the same time the Sojourner rover explored the surface of Mars, another scientific expedition -- this one going to the bottom of the North Atlantic Ocean -- gathered data that may help scientists get a better understanding of the origins of life on Earth and provide clues about how and where life might exist on other planets."
-- Environmental News Network, 8/7/97

NOAA VENTS Website
"The VENTS Program, established in 1984, conducts research on the oceanic impacts and consequences of submarine volcanoes and hydrothermal venting. The program focuses on understanding the chemical and thermal effects of venting along northeast Pacific Ocean seafloor spreading centers"
-- National Oceanic and Atmospheric Administration

Symposium on Evolution of hydrothermal ecosystems on Earth (and Mars?)
Program with abstracts
-- Ciba Foundation, London,January 30–February 1 1996

Archaic Genome
" The sequencing of the genome of ancient organisms found in inhospitable climates deep in
thermal vents under the sea should greatly advance understanding of the evolution of life on Earth."
-- - Access Excellence (Genentech, Inc., sole sponsor), national educational program for biology, 8/23/96

Fossil Hydrothermal Vent Community at Yaman Kasy, Russia
"Ancient analogues of these vent sites in the fossil record ... Several ancient VMS deposits contain fossils, mostly tube fragments of uncertain affinity. Museum scientists are currently working on a unique Silurian-age (430 million years ago) fossil assemblage from the Yaman Kasy VMS deposit in the Urals of Russia"
-- Natural History Museum, London, Department of Minerology

Scientists Unravel DNA of Bacteria
"... report identifying more than 1,500 genes of the bacterium Aquifex aeolicus. This heat-loving microorganism, which thrives in undersea volcanic vents where life is thought to have sprouted, has very simple requirements. It needs little more than hydrogen, oxygen, carbon dioxide and mineral salts to grow."
-- ABCNews.com, 3/25/98

MITI turns up heat on research into thermophile genes
"Japan's Ministry of International Trade and Industry (MITI) is stepping up its investment in genome-related research by financing the construction of a new research annexe at its Institute for Bioscience and Human Technology ..."
-- Nature, 6/6/96 (requires free registration)

Deep Sea Vents
List of links
-- Miningco.com

Aquarium test helps scientists look for life in extreme environments
"NASA's search for life elsewhere in the solar system is bringing space scientists to the giant kelp forest exhibit at the Monterey Bay Aquarium to test a new scientific probe that might one day look for life in oceans that may exist on Jupiter's icy moon Europa."
-- JPL, 8/20/98

Sea floor observatory set up at volcano
"Tubeworms living in 360 degree Celsius water, snow-blower vents, hydrothermal vents harboring what may be the oldest life form on Earth; these are a few of the things a team of oceanographers were looking for -- and found -- in their quest to establish a sea floor observatory at the Axial Volcano."
-- CNN.com, 10/21/98

Key chemical in life creation - ammonia - created at hydrothermal vents
"New high-pressure research ... reveals that unexpected chemical reactions occur in deep hydrothermal vents of the sea reactions that may have played a key role in the origin of life."
-- exosci.com, 10/23/98

Life Origins from Undersea Volcano
"Life probably started at similar hot springs as a way of speeding up the reaction of hydrogen with carbon dioxide in ancient ocean water.”
-- ABCnews.com, 10/9/98

from Bacteria DNA Unraveled
"The feat, reported in the British journal Nature, is important for its glimpse into the earliest life on hellishly hot Earth This heat-loving microorganism, which thrives in undersea volcanic vents where life is thought to have sprouted, has very simple requirements. It needs little more than hydrogen, oxygen, carbon dioxide and mineral salts to grow."
-- ABCnews.com, 3/25/98