Welcome To The Intertidal Zone

By: Savannah CalhounBrittney Daniel

     Madison HennesyEllen 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 ZonesAnimals 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 oxygeno 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 White Zone- true border between land and sea

o Gray Zone- Periwinkles and Nerites live here. Nerites are a tropical group that tends to replace limpets.

o Black Zone- immersed only at the highest spring tides and lack the knobby periwinkle

• Midlittoral Zoneo Yellow Zone- yellow or green because of the

microscopic boring algae covering its surface.

o 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.o Larger body size, lack of mobility

disadvantageous, no scales, compressedo body shape, absent swim bladder.

Sandy Shore Organisms

Sandy Shore• Role of waves and sediments

o 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.

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 ShoreMidlittoral Zone

• Vertical Zonationo 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.

Meiofauna• Meiofauna- include the animalsthat 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.