Scientists
often have a reputation for working in stuffy laboratories, cut off from the
world around them. But this certainly isn't the case at the Centre for
Geobiology, University of Bergen, Norway.
The
center has operated two summer cruises thus far in which researchers embarked
on voyages to study conditions on the ocean floor. Using state-of-the-art
technology, including a remotely operated vehicle, the scientists have
discovered a new field of deep-sea vents, one of the most northerly in the
world. [This discovery was reported
by LiveScience in July.]
Creatures
living around these "black smokers" show just how tough life on Earth
can be, and hint that organisms on other worlds may be able to thrive in very
hostile environments.
Life on the ocean floor
Scientists
used to think that life on Earth was always based on ecosystems with
photosynthesis — making food and energy from sunlight — as the foundation. Dive
deeper than 656 feet (200 meters) and you'll be lucky to see any light at all — below 3281 feet (1000 meters), there is none. Amazingly, researchers have found
organisms there, generally referred to as "extremophiles" (as they
exist in extreme environments), often thriving despite the harsh conditions.
Just
how unforgiving are environments deep in the ocean?
Creatures
living 1968 feet (600 meters) deep endure crushing pressures around 60 times more
powerful than at sea level. But that is only one of the problems they face. The
temperature on the sea floor is very low, averaging about 39 F (4 C). This
changes abruptly around hydrothermal vents, where temperatures can suddenly
soar up to 752 F (400 C).
These
vents, like the ones discovered during the research cruise, actually create
havens for life despite the scorching heat. Creatures that live in hot
environments are called thermophiles, which means "heat loving."
They're perfectly happy on the outskirts of vents, where the temperature is
around 122 F (50 C). Another group of organisms are known as hyperthermophiles.
They live up to this impressive name by thriving at temperatures up to 248 F
(120 C). Many chemicals spewed out at the vents are toxic to more common forms
of life, but some exteremophiles are so hardy that they actually can use these
chemicals for food and energy!
Scientists take to the seas
Elinor
Bartle is the Centre for Geobiology's Information Officer. She was part of the
Centre's team aboard the newest, largest and most advanced research ship in the
Norwegian fleet. After sailing for two days, they reached the first study site
off the west coast of Norway. Says Bartle, "Each leg [of the trip]
involved a group of around 25 researchers, technicians and public outreach
personnel in addition to the ship's crew. The group was international with
representatives from a number of international partner institutions."
Their
main mission was mapping the sea floor, hunting for areas of interest like
elusive vents. They also collected rock samples that could provide clues about
the local geology.
The
researchers found the black smokers on mineral deposits that may be among the
largest ever discovered, having been built up over the course of 100,000 years.
An entire ecosystem surrounds these newly-discovered vents, using
chemosynthesis for energy. Instead of light being the basis for energy,
chemicals from the vents supply the foundations for life. Samples of the
creatures were collected to be studied, and the hope is that they will help us
gain better understanding of extremophile life.
Alien parallels?
Studying
these organisms is very important for astrobiologists. Says Bartle, "We
are finding microbial organisms in unusual and extreme environments, and this
is providing extremely relevant information for the search for life on
other planets."
There
may be similar hydrothermal vents on the ocean floors of other worlds, such as
Jupiter's icy moon Europa.
Scientists also think that conditions around the vents could match what it was
like when life
first formed on the Earth four billion years ago. The deep ocean would have
provided protection from deadly solar radiation before the ozone layer had
formed.
The
summer cruise's results are certainly good news when thinking about life on
other worlds. The fact that there are many hydrothermal vents on the ocean floor
hint that they could be common on geologically active planets and moons. And
the existence of life in these areas indicates there could be havens for
biological communities spread throughout the solar system and beyond.
Having
been spurred on by these discoveries, Bartle says, "We are going to follow
up the cruise with intensive work to isolate, characterize and describe some of
the unusual microbes we have found in three different types of extreme settings
this summer. It is critical that we continue to build on the information we
have gathered this year."
advertisement
