1. Survival and Diversity
Life in the Tidal Zone
Survival and Diversity

2. High levels of primary (food) production: driven by phytoplankton
Tidal Habitats
Great places to live:
High levels of primary (food) production: driven by phytoplankton
Nutrient rich waters created from river drainage into the sea, and upwelling: the replacement of deep, cold water for surface water driven away by winds.

3. 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 it’s scavenged shell
Pipefish well camouflaged in eelgrass bed

4. 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

5. Tidal Zones Intertidal Zone
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
Most adaptation required
Middle Tide Zone
Low Tide Zone
Subtidal Zone

6. Splash Zone High on beach Out of water most of the time
Species must tolerate salt, heat, cold, and extended dry periods
Low diversity

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

8. High Tide Zone Increased wave action
Species must survive exposure to drying
Tide pools provide some protection
Higher diversity: includes some animals from splash zone and middle zone (in tide pools)

9. High Tide Zone Life
Barnacles
Limpets
Shore Crab
Rockweed

10. Middle Tide Zone Most active region Covered and uncovered twice a day
Life must tolerate BOTH submersion and exposure to air
Animals move in and out of adjacent zones to feed

11. Purple and Ochre Sea Stars
Middle Tide Zone Life
Wrinkled Whelks
Purple and Ochre Sea Stars
Aggregate Anemones
Green Algae
Blue Mussels

12. Low Tide Zone
Most diverse zone: more plants and animals in low tide zone than in all other zones combined
Most food and shelter
Less exposure to air and heat
Animals unable to exist in other zones

13. Opalescent Nudibranch
Orange Sea Cucumber
Low Tide Zone Life
Eelgrass
Black Katy Chiton
Purple Sea Urchin
Opalescent Nudibranch
Brittle Star
Calcareous Tube Worm
Giant Green Anemone

14. Subtidal Zone Just below Intertidal Zone Almost never exposed
Many consumer animals: prey on animals in low tide zone
Life forms less tolerant to changes: do not have adaptations to allow them to survive without water

15. Subtidal Zone Life
Wolf Eels
Pipefish
Jellyfish
Octopus
Salmon

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