1. Tidal Environments

2. A. Turbulence - wave action B. Keeps inshore waters from stratifying (layering) C. Causes substrate particles (sand) to remain suspended. I. Affects of Turbulence

3. II. Substrate A. Definition - material an organism lives in or on, including sand and rocks.

4. III. Tidal Zonation

5. A. Low-Tide Conditions 1. Epifauna – organisms living on substrate surface (intertidal zone organisms) 2. High stress for sessile organisms due to exposure of the elements. A. Desiccation – drying out B. Predation C. Temperature & Salinity changes 3. Survival Method A. Motile Organisms-Run & hide B. Sessile organisms-Clam up method

6. B. High Tide Conditions 1. Once Exposed Now Submerged 2. Force of crashing-in waves 3. Wave Intensity varies due to the bending of the waves

7. IV. Causes of Zonation A. Physical factors: Alternation between submersion and exposure to air B. Biological factors: 1. competition and predation 2. grazing-affects algal distribution 3. offspring reproduction-variable due to water conditions/weather and adult reproduction

8. V. Types of Tidal Zones Sandy Beach Rocky Shore

9. 1.Composed of loose sediment that’s easily shiftedby wind and waves. 2. Zones easily recognized 3.Sandy beaches are the most familiar of tidal zones. A. Sandy Beach

10. B. ROCKY SHORE 1. Occur on steep coasts (West Coast of America). 2. Formed from uplifts on tectonic plates or rising coasts from melting ice. 3. Lacking large amounts of sediment.

11. 4. Rocky Shore Zones Supralittoral zone Littoral zone Infralittoral zone

12. 5. Upper intertidal (Supralittoral zone) a. Conditions as terrestrial as they are marine b. Infrequent wetting by high tides and waves c. Sparsely inhabited by marine organisms

13. 6. Middle Intertidal (littoral zone) a. Frequently submerged by tides and waves; b. Abundance of plant nutrients, oxygen, and planktonic food c. Barnacle and Mussel habitation

14. 7. Lower intertidal (Infralittoral zone) a. Submerged most of the time b. Organisms tolerate only brief exposure to air c. Numerous seaweed species; algae – more red and brown than green d. Animals: anemones, snails, sea spiders, hydroids, sea stars, sea urchins, brittle stars, and sea cucumbers.