Intertidal Zone
What is the intertidal zone?
• Area between highest high tide (spring)
and lowest low tide (neap)
2 Types of Intertidal Zones
• Based on substrate:
• Rocky Intertidal
– Western Coast of US, Eastern Canada and
New England
• Sandy Intertidal
– Eastern and Gulf Coasts of US
Abiotic Factors
• Exposure to air
– Threat of high temp.
– Higher organisms live in intertidal, more time
exposed
• Desiccation – drying out
– Clam up
– Run and hide
• Wave shock
– Bigger problem along rocky shores
– Hits headland the hardest
Wave Refraction
Other Challenges
• Feeding Restrictions
– Filter feeders cannot eat when tide is out
• Predators
– More difficult to hide when tide is out
• Salinity fluctuations
– Decreases with rain
– Increases with evaporation