Phytoplankton are the
plant-like organisms of
the sea that carry out
photosynthesis and
float in the upper
areas of the world’s
oceans.
Most of the
ocean is too
deep for
plants to
attach to the
bottom like
this Giant Kelp
off the coast
of California.
Therefore,
most of the
photosynthesis
is carried out
by microscopic
single celled
organisms or
chains of
single cells.
These
organisms
often have
long
projections to
increase their
surface area
or oils to keep
them in the
photic zone.
Diatoms are
dominant
members of the
phytoplankton
that can be
caught in a net.
They are
especially
common in
temperate ,
coastal and
polar regions.
They have
sculptured
shells, or
frustules, made
of silica.
Diatoms can
come in a
variety of
shapes.
More Diatom Shapes
Life Cycle of a Diatom
Fish Killer
Some diatoms,
like this one
can kill fish
when found in
large numbers
The glasslike
projections
cause mucus
to build up in
the fish’s gill
which can
lead to the
fish's death.
Dinoflagellates
Dinoflagellates are
found throughout
the world’s oceans,
but tend to prefer
warmer areas.
Given nutrients,
dinoflagellates can
bloom or
explosively grow
to huge numbers
sometimes causing
RED TIDES
Dinoflagellates:
red tides
Florida red tide organism:
Gymnodinium breve
Around 60
species of
Dinoflagellates
are known to
cause red tides.
A few species
produce poisons
that are among
the most
powerful natural
toxins known.
During a red tide,
dinoflagellates
may poison the
waters, turning
the surface into
a sea of dead
fish.
Red tides can also
threaten human
health.
Mussels, clams
and other
bivalves store
the toxins as
they filter feed.
People who eat
the shellfish can
get Paralytic
Shellfish
Poisoning.
Victims suffer
numbness and
tingling, loss of
balance, slurred
speech, and in
extreme cases,
paralysis and
death!
Symbiotic Dinoflagellates
Some
dinoflagellates
like
Zooxanthellae,
are symbiotic
with corals or
jellyfish.
Coccolithophorids
Coccolithophorids
are common
members of the
nanoplankton.
Most are too
small to be
taken in a
regular plankton
net.
Though found in
coastal waters,
they do best in
open oceans
where they
often far
outnumber all
other types of
phytoplankton.
These single
celled
organisms are
covered by
plates made of
calcium
carbonate.
Silicoflagellates
Because of there
small size, very
little is known
about
silicoflagellates
except that they
can be very
important to the
primary
production in the
world’s oceans.