Welcome To The
Intertidal Zone
By: Savannah Calhoun
Brittney Daniel
Madison Hennesy
Ellen Ponder
Characteristics
• Definition: Part of marine environment
that lies between the highest tide and
the lowest tide.
• Interaction on the shoreline of wind,
waves, sunlight, creates a complex
environment.
• Organisms must be able to tolerate
radical changes.
Rocky Shore
• Shores composed of
hard material
• Either formed from
lava flow or highly
eroded areas
• Rocks provide stable
surface for animals to
attach themselves to.
Zonation
• Separation of
organisms into
different bands.
• Each level is
inhabited by
organisms adapted
to the special
conditions.
Animals in Zones
Animals must be well
adapted to temperature
change, gas exchange and
exposure to air.
Tide Pools
• Tide pools are
depressions in rocks that
retain water.
• Tide pools prevent
organisms from being
exposed to air, but they
present their own set of
difficult environmental
conditions.
o Loss of oxygen
o Decrease in salinity
o Lower pH
Wave Shock
• Animals that live in this zone have
compressed or dorsally flattened bodies of
shells that dissipate the force of waves.
Adaptations to Wave Shock
•
Organisms that live on
rocky shores have evolved
a number of different
strategies for dealing
with the crushing force of
waves.
o Cement bodies to
rock’s surface
o Hold tight to a rock
with muscular feet
o Hold with tough
byssal threads
o Some hollow out
cavities in the rock
Tide Pools
• Common organisms in tide
pools include various
species of algae, sea stars,
anemones, tube worms,
hermit crabs, and a variety
of mollusk species.
• Tide pool organisms are
filter feeders that feed on
phytoplankton and
zooplankton.
Tropical Rocky Shore
• Supralittoral Fringe
o
o
o
White Zone- true border between land and sea
Gray Zone- Periwinkles and Nerites live here.
Nerites are a tropical group that tends to replace
limpets.
Black Zone- immersed only at the highest spring
tides and lack the knobby periwinkle
• Midlittoral Zone
o
o
Yellow Zone- yellow or green because of the
microscopic boring algae covering its surface.
Pink Zone- lies under the yellow this is
characterized by the widespread encrustation of
coralline algae.
Intertidal Fishes
• Fish that visit the intertidal zone are
divide into two groups: residents and
temporary inhabitants.
• True residents have special adaptations
for surviving harsh conditions of the
intertidal zone.
Larger body size, lack of mobility
disadvantageous, no scales, compressed
o body shape, absent swim bladder.
o
Sandy Shore Organisms
Sandy Shore
• Role of waves and sediments
Swash- water running up a beach after a wave
breaks.
o Backwash- the water flowing down the beach.
o Dissipative beach- wave energy is strong but is
dissipated in a surf zone some distance form
the beach face.
o Reflective beach- wave energy is directly
dissipated.
o
Comparison of Rocky
and Sandy Shores
• Sandy beaches lack a readily apparent
pattern of zonation and superficially
appear barren and devoid of life.
• Wave action determines organism
distribution.
• Temperature has less of an effect on
inhabitants of sandy shores than those of
rocky shores.
Life in the Sandy Shore
Midlittoral Zone
• Vertical Zonation
Zone of retention- retains moisture at low
tide because of the capillary action of water.
o Zone of resurgence- water is retained at low
tide and supports different crustaceans and
polychaete worms.
o Zone of saturation- constantly moist and
support the greatest diversity of organisms.
o
Meiofauna
• Meiofauna- include the animals
that pass through a 0.5-millimeter
screen but are retained by a
62-micrometer screen. (basically
really small organisms)
• Entirely aquatic and grain size.
• Major phyla include: ciliates, flatworms,
and nematodes.
• Minor phyla include: gastrotriches,
kinorhynchs, rotifers, tardigrades, and
priapulids.
Works Cited
• "Intertidal Zone - Google Search." Google. Web.
03 Dec. 2010.
<http://www.google.com/images?um=1&hl=en&
biw=1596&bih=691&tbs=isch:1&aq=f&aqi=g10
&oq=&gs_rfai=&q=intertidal zone>.
• Karleskint, George, Richard L. Turner, and
James W. Small. Introduction to Marine Biology.
Southbank, Victoria: Thomson, 2006. Print.