Hydrothermal
Vents
http://www.divediscover.whoi.edu/vents/ventbio-infomod.html
History
• In 1977, scientists made a stunning
discovery on the bottom of the
Pacific Ocean that forever changed
our understanding of planet Earth
and life on it.
• They found seafloor vents gushing
shimmering, warm, mineral-rich
fluids into the cold, dark depths.
• And, to their complete surprise,
they found that the vents were
brimming with extraordinary,
unexpected life.
Hydrothermal Vent Basics
• Hydrothermal vents are one of the most spectacular
features on the seafloor.
• Hydrothermal vent = a deep-sea hot spring where
heated seawater forces its way up through the
crust.
• They form in places where there is volcanic activity,
such as along the Mid-Ocean Ridge.
Hydrothermal Vent Basics
Video
• Water seeps through cracks
in the seafloor and is heated
by molten rock deep below
the ocean crust to as high as
400°C (752F).
• The hot fluid rises to the
surface and gushes out of
the vent openings. This
hydrothermal fluid carries
with it dissolved metals and
other chemicals.
ZOARCID
FISH
Hydrothermal Vent Energy Source
• Sunlight does not reach the hydrothermal
vent communities at the bottom of the ocean.
• Instead, the microbes get their energy from
different chemicals in hydrothermal fluid.
• For example, some get their energy by
breaking down hydrogen sulfide.
• This process is called chemosynthesis.
Video
Copper, iron,
zinc, Silver can
be mined here!
Chemosynthetic Bacteria
are producers, use
hydrogen sulfide to make
energy! Tubeworms
&bacteria - symbiotic
relationship
• Some bacteria live inside tubeworms, clams, and
mussels, forming symbiotic relationships with these
animals.
Black Smoker
• The “black smoke”
pouring out of the
chimneys is not, in fact,
smoke.
• Rather, it is the
hydrothermal fluid that
is so hot, it can melt
metal.
• When the fluid mixes
with sea water, these
metals combine with
sulfur to form tiny black
particles, which make
the fluid look like smoke.
Hydrothermal Vent Chemistry
Video
Vents Around The World
• Hydrothermal vents are found only in areas where
there is volcanic activity and the magma is close
enough to the surface to heat the fluids.
• Most of the vents scientists have discovered are
along the Mid-Ocean
Ridge.
• Vents are also found
along some subduction
zones.
• Vents can occur at any depth. Some are as deep
as 3,600 meters. Others off the coast of New
Zealand are only 30 meters deep.
• Vents are also found on land. Two of the most
famous examples are the hot springs and
geysers in Yellowstone National Park in the
United States and on the North Island of New
Zealand.
Live Yellowstone Geyser
Hydrothermal Vent Biology
Hydrothermal Vent Life
• Octopi: There are several species of octopi that
only live around hydrothermal vents. Some
species have been seen a few times.
• They are typically one meter long and their heads
are about the size of an orange.
• Octopi are top (apex)
predators
• They live among or even
under clumps of
mussels.
• They eat crabs, clams, and
mussels.
• Tubeworms: live around hydrothermal vents
along the Mid-Ocean Ridge in the Eastern Pacific
Ocean. They can grow up to two meters long and
ten centimeters in diameter.
• Tubeworms never leave their tubes, which are
made of a hard material called chitin. The tubes
help protect the worms from the toxic vent
chemicals and from
predators such as
crabs and fish.
• Tubeworms do not eat. They have neither a mouth
nor a stomach. Instead, billions of symbiotic
bacteria (or Archaea) living inside the tubeworms
produce sugars from CO2 , hydrogen sulfide, and
oxygen. The tubeworms use some of these sugars
as food.
• Zoarcid Fish: These two-foot long white fish are top
predators around vents.
• They eat everything from tubeworms to shrimp.
• Despite their huge appetites, these fish are slow
and lethargic.
• Mussels: often the first shellfish to colonize
hydrothermal vent sites.
• They clump together in cracks in the seafloor.
Symbiotic microbes live in mussels’ gills. Like the
microbes living inside tubeworms, these microbes
use energy from chemicals in the vent fluids to
produce sugars.
The mussels use
sugars produced by
the symbiotic
bacteria for food.
• Mussels can also filter food from the water, so if
hydrothermal fluid stops flowing, mussels can
survive for a short period of time.
Video
• Microbes: Hydrothermal vent microbes include
bacteria and Archaea, the most ancient forms of
life.
• These microbes form the base of the food chain.
• They are chemo-autotrophic, meaning they harvest
energy from a variety of different chemicals gushing
out of the vents.
They use the
energy to
manufacture
sugars from
carbon dioxide.