The Mariana Trench - Biology (cont.)
A Closer Look at Life in the Trench
We have mentioned that the creatures which inhabit the Mariana Trench
are all uniquely designed to survive in its extreme environment, but
contrary to what one might readily assume, these life forms are not
the result of evolution and adaptability - Quite the contrary, they
are perhaps the most prehistoric life forms on the planet, some
species, such as the Indians Ocean's deep-sea dweller the Coelacanth
which has remained unchanged for millions of years.
There is much to learn about the origins of life on the planet by
studying the denizens of the deep.
While plants and other organisms on the planet's surface convert
water, minerals and carbon dioxide into nutrients by gathering light
in their pigments through the process of photosynthesis, the plants
and microorganisms of the deep use a process called chemosynthesis to
convert the chemically rich discharge of hydrothermal vents into food.
Hydrothermal vents, also called "black smokers" are chimney like
undersea geysers which spew out sea water which has seeped in and come
in contact with the hot volcanic core. The discharge of
hydrothermal vents is a black smoke which contains a variety of
chemicals and dissolved metals, which are then consumed or processed
by the microorganisms, animals, and plants. Vents which
have been active for a long period grow to resemble chimneys; some of
them reaching heights of over 15 meters (49 feet).
As we have mentioned before, certain deep-sea animals feature
bioluminescent appendages and features which serve a wide variety of
purposes, from mating to self-preservation, and even hunting, as is
the case with the Angler Fish. Bioluminescence is light
generated by a living organism as the result of an internal chemical
reaction. The only surface animal which features this
ability is the Pyractomena borealis, also known as the Firefly.
Animal: The Coelacanth
Creatures of the Deep: Hidden Depths
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