Rocky and Sandy Shores FC PT Flashcards
(21 cards)
What causes permanent rock pools on rocky shores?
Erosion in the rock fills with water.
How does light intensity affect rocky shore organisms?
High at surface, reduced underwater; organisms adapt with behaviors or shells.
How do organisms on rocky shores deal with desiccation?
Shells trap water; seaweeds use gels or dehydrate safely while retaining moisture.
What are euryhaline organisms?
Species that tolerate a wide range of salinities; essential near high-tide areas.
How does sand cover affect rocky shore organisms?
Must be dormant or grow fast above sand; sand movement can kill, but areas are quickly recolonized.
How do organisms survive limited oxygen?
Use water trapped around them or cope with oxygen scarcity while exposed.
What are the three rocky shore zones?
Upper eulittoral (Littorina), Middle eulittoral (Balanoid), Lower eulittoral.
What characterizes upper eulittoral?
Dry for days, exposed to extremes, less predation or wave action.
What characterizes lower eulittoral?
Limited exposure; heavy wave action; intense competition and predation.
What is the cochlear zone?
Band of pear-shaped limpets on the south & west coast lower eulittoral zones.
How do limpets create mutualism with algae?
Grazing algae in rotation, defending gardens, allowing regrowth; symbiotic farming.
What is the infratidal zone?
Below spring low-tide mark, with dense beds of red bait.
Why are sandy shores unstable?
Constant motion of sand by waves; no hard substrate.
How do animals adapt to sandy shores?
Burrowing protects from waves, predators, and temperature extremes.
What happens to oxygen in fine sand?
Excluded; anaerobic bacteria thrive, releasing hydrogen sulphide.
Key upper sandy shore animals (west/south)
Sand hoppers and giant pill bugs; emerge at night to feed on decaying kelp.
Key sandy shore animal on east coast?
Ghost crab; scavenger that burrows deep and feeds on dead animals.
What defines Plough snail behavior?
Surf tide up, feed on carrion, smell cues guide them to food, burrow back after.
Key lower sandy shore animals?
White mussels (filter), surf shrimps, Mole crabs; feed in turbulent zone.
What is meiofauna?
Microscopic organisms between sand grains; drive nutrient cycling.
How do sandy shores recycle nutrients?
Bacteria break down organics to nutrients, which become phytoplankton food via meiofauna chain.
