The Mariana Trench - Biology
 The
deepest part of the ocean is called the abyssal zone. it is host to
thousands of species of invertebrates and fish including such oddities
as the Angler Fish (see illustration), so called because it uses
a bioluminescent (life light) protrusion to attract its prey. The
Challenger Deep in the Mariana Trench is very cold,
and highly pressurized; its floor features hydrothermal (hot water ) vents formed by spreading
tectonic plates which release hydrogen sulfide and
other minerals which are consumed by the barophilic bacteria which are then
consumed by other microorganisms, which are in turn, consumed by the
fish, and so on. The temperature around the vents
can reach up to 300° Celsius (572° Fahrenheit). The
venting fluid is highly acidic, while the water from the deep ocean is
slightly basic. Although the venting fluid is prevented from boiling
due to its dissipation into the surrounding freezing water,
creatures from the deep show an incredible resistance to temperature
extremes by having different proteins which are adapted for life under
these conditions; allowing the animals to eat, process food,
and reproduce.
The highest temperature bacteria can withstand is 113° Celsius (235°
Fahrenheit), and the highest any animal can withstand is 50°
Celsius (122° Fahrenheit). One animal which thrives near
hydrothermal vents is the Bythograea thermydron, of "Vent Crab" -
their numbers are so vast that scientists are using the crab clusters
to locate hydrothermal vents.
Crabs and Angler Fish are but few of the many species of the Mariana
Trench. One mud sample taken from Challenger Deep by
Oceanographers from the Kaiko yielded nearly over 200 different
microorganisms. Although there seems to be an abundance of life
at these depths, no human being could withstand the pressure extremes.
Another interesting characteristic of these deep sea creatures is
their longevity; many of these animals having a lifespan of over one
hundred years, provided of course that they do not end up in fishing
nets. Since these creatures seldom migrate and are slow to
develop, there is growing concern over their endangerment.
Most of the planet's oceans are very dark. At a depth of 150
meters (approx. 500 feet), there is little if any light left, and
colors are no longer visible to the human eye. As odd as it may
seem, we know more about outer space than we do about the deep oceans
of our own planet.
The ocean floor at such depth consists of pelagic sediment, also
known as biogenous "ooze". Pelagic
sediment is composed of shells, animal skeletons, decaying
microorganisms and plants; it is generally yellowish and very viscous.
Continued »
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Fact Finder
The deep sea represents 80% of the biosphere, which
makes it the largest habitat for creatures on the planet Earth.
creatures from the deep show an incredible
resistance to temperature extremes by having different proteins which
are adapted for life under these conditions.
At a depth of 150 meters (approx. 500 feet), there
is little if any light left, and colors are no longer visible to the
human eye. |
