This document discusses the tidal zone and the adaptations required for organisms to survive within it. The tidal zone is divided into four zones - splash zone, high tide zone, middle tide zone, and low tide zone - based on how often each is covered by water. Organisms in each zone have adapted in ways such as avoiding desiccation, resisting waves, and protecting themselves from predators in order to survive the varying environmental conditions caused by the tides. Examples of adaptations include barnacles fitting tightly to rocks and sea stars using tube feet to anchor themselves.

1. Life in the Tidal Zone
Survival!

2. Objective: I can identify biotic and
abiotic factors in marine ecosystems
and describe how they interact with
one another.
 Essential Question: How do
adaptations increase the likelihood of a
species’ survival in the intertidal zones?

3. 2 Major ecological concepts
are in effect:
 Competition
 For Space
 For Resources (food, water, space…)
 Adaptations
 To prevent desiccation (drying out)
 To anchor themselves
 To protect themselves

4. 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
Protect themselves from predators
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
Hermit crab
hiding in it’s
scavenged shell
Pipefish well
camouflaged in
eelgrass bed

5. COOL VIDEO!!
https://www.youtube.com/watch?v=kGMCaTwkKrc

6. Types of Tidal Habitats
Sandy Beaches and Mud Flats Rocky Shores
Different tidal habitats require different adaptations
• Substrate offers lots of nutrients,
but little structure for attachment
• Animals bury themselves in mud
• Can also attach to plants
• Little protection from strong waves:
animals must anchor
• Complex tide pools possible
• Seaweeds offer protection from
drying

7. Tidal Zones
Splash Zone
High Tide Zone
Middle Tide Zone
Low Tide Zone
Zones
affected daily
by changing
tides
Adaptations
are required
to avoid
drying out,
wave action
and predators
Intertidal Zone
High, Mid and Low
Tidal habitats are divided into zones based on relative
beach location and how often they are covered by water
Tides are controlled by moon’s
gravity pulling on the ocean.

8.  High on beach
 Out of water most of the time
 Species must tolerate salt, heat,
cold, and extended dry periods
 Adaptation example: Barnacles
and algae are most tolerant to
desiccation (drying out)
Splash Zone

9. Splash Zone LifeSplash Zone Life
Amphipods
Periwinkles
Isopods
Blue-Green
Algae
Lichen

10.  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
High Tide Zone

11. High Tide Zone LifeHigh Tide Zone Life
Acorn BarnaclesLimpets
Shore Crab
Rockweed
Anemones
Hermit Crabs
Black
Turban
Snails

12.  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
an ochre sea star allow it to suction
on to surfaces
Middle Tide Zone

13. Middle Tide Zone LifeMiddle Tide Zone Life
Gooseneck
barnacles
Ochre sea star
Sea palmsAnemones
California mussels Black leather
chitons
Click here for a quick video!

14.  Most food and shelter
 Most diversity of organisms compared to other
zones
 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: Anemones have tentacles that inject
a paralyzing neurotoxin when touched
Low Tide Zone
(Subtidal zone)

15. Low Tide Zone LifeLow Tide Zone Life
Nudibranch
(sea slug)
Kelp crabs
Gumboot Chiton
Purple sea
urchin Giant Green Sea
Anemone
Coralline algae
Bull kelp

16. Summary
Exposure to Water
Most time
Each zone requires unique
adaptations for survival
Splash Zone
High Tide Zone
Middle Tide Zone
Low Tide Zone

17. Intertidal Zone Organisms

18. What is an Estuary?
An estuary is a
semi-enclosed body
of water where
freshwater meeting
and mixes with
saltwater.