Lecture 8 - Rocky Shores Flashcards
Are rocky shores generally high or low energy?
High, depending on their exposure to waves.
In what way are rocky shores similar to reefs?
They are autochthonous - energy is derived from the same location that it is used.
What acts as food for detritivores in rocky shores?
Broken/rotting seaweed
Name four factors that favour life in a rocky shore environment.
- High primary productivity
- Low sediment supply
- Stable substrate that erodes slowly
- Diverse habitat types present (ledges, overhangs, crevices, pools etc.)
Give seven challenges faced by organisms in a rocky shore habitat.
- Desiccation
- Wave action
- Temperature fluctuation
- Salinity fluctuations
- Range of illumination
- Double predation
- Pollution
Give the three zonations in a rocky shore environment.
- Upper shore (furthest from ocean)
- Middle shore
- Lower shore (edge of ocean)
What is the main physical factor for marine organisms living in rocky shores?
Submergence
What organisms are often present in the upper shore, supra-littoral zone?
Lichens
Which zone of a rocky shore does tide never fully cover?
The ‘splash zone’, above the upper shore.
Name an organism found in high water.
Brown algae/seaweed.
Pelvetia canaliculata
Name the seaweed found at low water.
Fucus serratus
What is the fleshy algae normally found at the bottom of rocky shores?
Laminaria species.
Where on the rocky shore are limpets found?
At highest high tide.
What kind of organisms are normally found at lowest tide zone?
Soft-body organisms, such as sponges.
Name a species of lichen that is similar to a marine woodlouse.
Ligia italic
Name an organism found in the intertidal / Eulittoral zone within the:
a) Upper littoral
b) Mid-littoral
c) Lower littoral
a) Upper littoral = barnacles
b) Mid-littoral = limpets
c) Lower littoral = Actinia species (anemone)
Name some organisms that are found in the sublittoral.
- Kelps
- Soft sponges
- Urchins
Why do organisms at the bottom of the shore need to be more sticky?
Exposed to surging waves, which can remove things.
Name four biotic factors determining the distribution of organisms in a rocky shore habitat.
- Thermal tolerance
- Food availability
- Competition (for space and resources)
- Predation
Describe seaweed zonation in a rocky shore.
- Top of shore; Helvetia
- Upper shore; Fucus spiralis
- Mid shore; Fucus vesiculosus and Ascophyllum.
- Then Fucus serrates
- Then Laminaria