Download Phytoplankton - Madison County Schools

The Role of Single-Celled
Organisms in the Oxygen
and Carbon Cycles
Phytoplankton
• The name “phytoplankton” comes from the Greek
word “phyto” that means “plant” and “plankton”
that means to “wander or drift”.
• Phytoplankton are microscopic drifting plants that
live in aquatic environments, but are not restricted
to the oceans. They come in lots of shapes, colors,
and varieties – ranging from single-celled
photosynthetic bacteria (cyanobacteria) to plantlike diatoms (a major group of algae) and armorplated cocolithophores (eukaryotes – Protista –
marine plants).
Phytoplankton
Photosynthesis
• REMEMBER – about 71% of the earth is made up of
water. In this water, phytoplankton are living. That
means that these single-celled organisms are going
through photosynthesis and releasing oxygen back
into the air.
• It is hard to believe, but these organisms are
producing as much or more oxygen than the trees
and plants on land. How can this be? Well – land
makes up about 29% of the earth and not all of it is
covered with plants.
Photosynthesis and the Cycles
• The phytoplankton’s photosynthesis abilities impact
the carbon and oxygen cycles in a big way!
• There are so many of these organisms and they
collect a vast amount of carbon dioxide. They use
the carbon dioxide for photosynthesis and they also
store it inside. They also release oxygen back into
the atmosphere.
• Phytoplankton are also a first link in the food chain
(a primary producer). When they are consumed,
some carbon makes its way back to near-surface
waters. When they die, the carbon can be buried in
the depths of the ocean (think fossil fuels).
Phytoplankton: Small Organisms
with a Massive Impact
• According to scientists, phytoplankton ”have
played, and continue to play, such principal roles in
shaping the Earth’s biogeochemical composition.
They…provide the elements necessary for all other
organisms to survive.”
• Science Daily says that “Phytoplankton is the fuel
on which marine ecosystems run. A decline of
phytoplankton affects everything up the food chain,
including humans.”