1. Science 112: Brian Saunders Intertidal Communities

2. Intertidal Stressors Water loss Heat balance Mechanical stress
Respiration
Feeding
Salinity stress
Reproduction

3. Resistance to Water Loss
Behavior
Enclose body
Seaweed tolerance

5. Resistance to Overheating
Large body size
Behavior
Ridges and flutes
Light color
Water compartment
Freezing is not as much of a problem

6. Resistance to Mechanical Stress
Squat body form
Streamline
Flexible
Sessile  thick shell
Mobile  shelter

7. Respiration Water reserve Vascularized mantle Operculum
Vascularized skin

8. Other Adaptations Feeding Salinity stress Reproduction
Usually when submerged or at night
Salinity stress
Osmoconformers or use water reserve
Reproduction
Coordinated with tides (timing)

9. Intertidal Zonation Distinctive bands of organisms Found globally
Causes?

10. Intertidal Zonation Distinctive bands of organisms Found globally
Causes?
Slope / exposure
Emergence (critical tides?)
Biological

12. Intertidal Zonation An organisms distribution boundary
Upper limit set by physical tolerance
Lower limit set by biological interactions

13. Biological Interactions
What are the major ways species interact in the intertidal?
Competition
Predation
Grazing
Larval recruitment

15. Grazing and Zonation Grazers select tasty species
Grazers have physical limits
Grazers can affect algal morphology (bet-hedging)

16. Algal Morphology
Mastocarpus species
Foliose form
Crustose form

17. Tide Pools
Temperature, Salinity, Oxygen, Grazers

18. Washington
l Thursday, July
47°36.2'N122°20.4'W
Marina Beach

19. Grazers on the Beach

20. Beach Hoppers

21. Idotea isopod

22. Periwinkle snails

23. The Limpets

24. The Chitons

25. Purple & Green Shore Crab

26. The hermit crabs

27. Predators on the Beach

28. The Whelks

29. Lewis’ Moon Snail

30. The Crabs

31. Worms

32. The Anemones

33. The Sea stars