Intertidal Zones
General Characteristics
- Unique among marine environments because it is regularly exposed to the air (emersion/immersion)
- Community depends on type of bottom substrate (rocky and hard vs. sandy and soft))
- Located on the shoreline between high and low tide)
- The Tide Pool Song and its lyrics!
Rocky Shore Communities
- Steep coasts without large amounts of sediment
- Organisms live on rock surface and undergo great physical stress because they are always exposed
- Exposure at low tide can result in
- dessication
- Run and hide (tide pools)
- Clam up
- Extreme changes in temperature and salinity
- Lack of food, especially for filter feeders
- Risk of predation
- Organisms must be able to withstand or protect themselves from wave shock
- Seaweeds have holdfast
- Barnacles use glue substance
- Mussels hold on with byssal threads (hairy looking protein fibers)
- Some fish have suction cups to hold on and lack swim bladders to they sink
- Food is not a limiting resource
- Plenty of light for photosynthesis
- High tide washes in detritus
- Biggest problem is competition for space to latch on to rock
- Vertical zonation
Soft Bottom Communities
- Composed of sediment instead of rock, animals can burrow easily
- Unstable and constantly shift in response to waves, tides, currents
- Particle size determines type of sediment
- Fine sediments in calm waters, coarse sediment in areas with more wave action
- Organisms mostly deposit feeders of detritus
- Oxygen in sediments used up very quickly and water circulation is very important for replenishment since there’s no photosynthesis
Random Pictures from our Gallery!
