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Frontiers
Take a Stroll Through the Octopus's Garden
February 1996
Most of us will never see the part of the ocean
that biologist Cindy Van Dover studies. Associate professor of oceanography
at the University of Alaska and a Navy-certified pilot of the submersible
craft Alvin, Van Dover explores the ocean's deepest depths, studying
life that is supported not by sunlight and photosynthesis but by hot
vents and chemosynthesis.
Scientifically speaking, Van Dover works in a new world. In her recent book,
The Octopus's Garden, the NSF grant recipient describes discoveries of life forms
previously unknown.
Some excerpts follow:
'SOUP IN THE SORCERER'S KETTLE'
A sample bottle of vent water opened in the laboratory can clear a room
in seconds as the ripe odor of rotten egg escapes. A variety of bacteria
thrive on the sulfide, using its chemical energy through chemosynthesis
in much the same way that plants use energy from light to produce organic
carbon through photosynthesis.
The stunning implication is that submarine hydrothermal systems, fueled by the
heat of volcanic processes, can support life in the absence of sunlight. Vent
water may be the ultimate soup in the sorcerer's kettle. The water has a primeval
chemistry that has prevailed along mountain ranges since the breakup of Gondwanaland.
... Deep-sea vents may have been the site where life originated on this planet.
The life from this water is sometimes odd, Van Dover writes, but as she investigates
she derives satisfaction not only from her scientific work, but also from the
new aesthetics.
'A CHORUS OF TUBEWORMS'
A painted tropical fish can be just a lost rainbow among the gaudy carnival
of colors of a coral reef; a vividly feathered tropical bird is veiled in a green
lace of leaves and twigs. But giant tubeworms [of hydrothermal vents] are 6-foot-long
expletives, shouts of brilliance, startling in their vivid simplicity and exposure.
Crimson plumes bloom atop long white tubes that emerge from cracks in glossy
black lava. Warm water rising up from a vent ruffles the leaf-like lamellae of
the plume. There must be a special cue in the vent effluent, a chemical billboard,
that causes a cohort of tiny tubeworm larvae to settle out of the water to grow
together side by side as dense thickets of tubes because often the tubes are
nearly all the same size and growing in parallel array. The growth of the whole
guides the growth of one: a chorus of tubeworms.
While the landscape is often desolate, after many dives, Van Dover has found
a favorite spot.
'BLACK SMOKERS'
Give me a dive where I am free from any obligation to collect samples or data,
a day just to do whatever I want as if I were on a picnic on a lazy Sunday afternoon.
I will spend that day in a field of black smokers, just looking.
Raw and powerful, black smokers look like cautionary totems of an inhospitable
planet. Like the undersea volcanoes that drive them, black smokers are born of
primal forces, a consequence of the first-order geophysical processes that control
the motions of our ocean's crust. I have often worked black smokers in Alvin
and I never fail to be awed by them. Approach the simplest structures: they first
loom as tall dark shadows, black against surrounding blackness at the gloomy
edge of Alvin's pool of light. ... As you ascend the chimney, watch for hot water.
It is usually at the very top, sometimes 6 or more meters above the seafloor.
Chimney walls may be leaky and alive with animals drinking up a warm seepage
of noxious chemicals, or the chimney might be hot and young and sterile, devoid
of life.
From the book The Octopus's Garden. Text Copyright© 1996
by Cindy Lee Van Dover. Reprinted by permission of Addison-Wesley Publishing
Co. Inc. All rights reserved.
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