1. Marine Shores: Life Between the Tides Toni Christopher

2. Overview Geography Structure Physical Conditions Chemical Conditions Biology Human Influences

3. Geography Intertidal Zones – Area covered and uncovered by the tides – Tide pools, salt spray, and sweet smelling kelp Thousands of kilometers(.6 miles/km) worth worldwide Can be either exposed(rocky) or sheltered(sandy/muddy) shores

4. Structure

5. Physical Conditions: Light and Temperature Light – Varies with the tide High tide, water turbulence = less light Low tide = full sun Temperature – Every changing; varies with tide and location Low tide= below freezing at high latitudes when exposed to air; above 40  C(104  F) in tropics and subtropics High tide = temperature is that of water, 17  C(62.6  F)

6. Physical Conditions: Water Movement: Tides and Waves Tides – Vary in strength and frequency Semidiurnal or diurnal Can vary from few cm to 15m in Canada’s Bay of Fundy – Affected by alignment of both sun and moon At full and new moons, sun, moon, and Earth align; stronger tides; called Spring At ¼ and ¾ moons, sun and moon at right angle, opposing one another; weakest tides; called Neap Size and location of bay, sea, coastline, etc determine if sun and moon effect amplified or dampened Waves – Vary greatly from area to area; affect distribution of life Headlands vs. Coves and Bays

7. Chemical Conditions: Salinity and Oxygen Salinity – Varies more on the shores than in the oceans Desert shores: higher from evaporation Rainy shores and tropics in wet season: much lower Oxygen – Amount typically not a limitation factor Species exposed to air at low tides Water is mixed and well oxygenated – Exceptions are sandy/muddy shores of sheltered bays, etc that don’t have good water circulation

8. Biology Life adapted to a marine/terrestrial existence – Covered and uncovered by tides periodically Zonation of species – Species live where best adapted Habitats include tide pools, the different zones, salty streams, sandy/muddy shores, and rocky shores

9. Human Influence Some species devastated by humans – Mussels, oysters, clams, etc Exploitation for food, education, and research Oil spills pollute and ruin habitats Introduction of non-native species on bottoms of ship hulls

10. Resources Molles, Manuel C Jr. Ecology, Concepts and Applications. Fifth Ed., 2010. http://studentweb.cortland.edu/knowles 86/Intertidalzone.gif http://www.clarku.edu/departments/bio logy/biol201/2002/JLagliva/Organisms. html Google Images