Intertidal Communities Lecture 6: Suez Canal University

Intertidal Zone

• The area between the highest high tide and lowest low tide is called the intertidal zone.

Beach Zones

• The beach below the mean low water is described as the sublittoral zone.
• The area extending from above the high tide to the dunes is called the supralittoral zone.

Ecological Factors

• Abiotic factors are physical or nonliving factors that shape an ecosystem.
• Biotic factors are biological influences on organisms within an ecosystem.

Intertidal Community Challenges

• The main challenge for intertidal communities is dealing with drastic fluctuations in salinity and water loss (desiccation).
• Extreme heat is a challenge for sessile animals in intertidal communities, which they deal with by estivating or burrowing underground.

Adaptations

• Algae in intertidal communities withstand water loss in tissues by producing protective compounds and drying out slowly.
• The primary mode of feeding for almost all sessile animals in intertidal communities is filter feeding.

Behavior and Migration

• Mobile animals in intertidal communities respond during low tide by migrating to find shelter or food.

Zonation

• 'Zonation' in the rocky intertidal occurs due to the vertical gradient of environmental conditions.

Species Adaptations

• Littorina (Periwinkle) has adapted to deal with extreme heats by producing a thick shell and estivating during low tide.