Life in the Tidal Zone

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Life in the Tidal Zone

• Survival!

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What is an Estuary?

• An estuary is a semi-enclosed body of water where
  freshwater meeting and mixes with saltwater.

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Tidal Zone Adaptation

• Tidal habitats change daily with the tides,
• so organisms adapt, or adjust to changing
• environmental conditions with special features
  to

Avoid drying out
Anchor themselves to resist waves
Limpets shape their shells to fit a specific
rock effective seal against water loss
Tube feet of sea star used for locomotion and
suction/anchorage
Protect themselves from predators
Hermit crab hiding in its scavenged shell
Pipefish well camouflaged in eelgrass bed
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Types of Tidal Habitats
Different tidal habitats require different
adaptations
Sandy Beaches and Mud Flats
Rocky Shores

• Little protection from strong waves animals
  must anchor
• Complex tide pools possible
• Seaweeds offer protection from drying

• Substrate offers lots of nutrients,
• but little structure for attachment
• Animals bury themselves in mud
• Can also attach to plants

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Tidal Zones
Tidal habitats are divided into zones based on
relative beach location and how often they are
covered by water
Splash Zone
Intertidal Zone High, Mid and Low
High Tide Zone

• Zones affected daily by changing tides
• Adaptations are required to avoid drying out,
  wave action and predators

Middle Tide Zone
Low Tide Zone
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Splash Zone

• High on beach
• Out of water most of the time
• Species must tolerate salt, heat, cold, and
  extended dry periods
• Adaptation example Amphipods bury themselves to
  stay moist when the tide is out.

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Splash Zone Life
Lichen
Blue-Green Algae
Isopods
Amphipods
Periwinkles
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High Tide Zone

• Increased wave action
• Tide pools provide some protection
• Adaptations include ability to survive exposure
  to air without drying out and to survive wave
  action.
• Adaptation example Anemones survive wave action
  by attaching themselves to the sheltered side of
  large rocks

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High Tide Zone Life
Limpets
Anemones
Barnacles
Shore Crab
Rockweed
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Middle Tide Zone

• Most active region
• Covered and uncovered twice a day
• Life must tolerate BOTH submersion in water and
  exposure to air
• Animals move in and out of adjacent zones to feed
• Adaptation example The tube feet of a star fish
  allow it to suction on to surfaces

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Middle Tide Zone Life
Wrinkled Whelks
Pisaster Sea Stars
Anemones
Japanese Eelgrass
Batillaria snail
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Low Tide Zone

• Most food and shelter
• Less exposure to air and heat under water for a
  lot of the time
• Animals unable to exist in other zones because
  they will dry out
• Adaptation example Tube worms build hard tubes
  around their soft bodies for protection

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Low Tide Zone Life
Black Katy Chiton
Orange Sea Cucumber
Opalescent Nudibranch (sea slug)
Tube Worm
Native Eelgrass
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Summary
Splash Zone High Tide Zone Middle Tide Zone Low
Tide Zone
Each zone requires unique adaptations for survival