Download Rocky Shore Zonation - Field Studies Council

Rocky Shore Zonation
The Rocky Shore ecosystem is very diverse due to the increased nutrients and light
that come from being close to the surface.
However, the organisms living there need to be able to cope with the tides.
Spiral Wrack
Egg wrack
Bladder wrack
Saw wrack
Species
Zonation..... the variation in the distribution of organisms
caused by differences in both biotic and abiotic conditions
along an environmental gradient.
Gutweed
Sea lettuce
Irish Moss
Coralweed
Sea laver
TIDES The gravitational pull of the moon and the sun create a bulge in the ocean
1
2
3
4
5
on either side of the earth. The earth then spins within this bulge creating two high
tides and two low tides each day.
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7
8
9
Station number
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11
12
Method An Interrupted belt transect with 0.6m intervals
running up the shore was used to assess the relative
abundance of all the species present. ESACFOR abundance
scale was used to describe the abundance of each organism
Theseashore
within a 1m2 quadrat. The data could then be plotted on a kite
histogram to clearly show the replacement of one species
A cross staff was used to move
with another along the environmental gradient.
0.6m vertically up the shore
Rocky shore
advantages
Abiotic Factors Causing Rocky Shore Zonation
Desiccation: occurs as a result of emersion at low tide affecting the upper and middle shores.
Light: is needed for photosynthesis. Seaweeds need to be in seawater for this to occur. However, the water
will filter off some of the wavelengths of light and reduce the intensity.
Organisms living on the
rocky shore have different
adaptations to these
factors and therefore will
be able to survive at
different heights on the
shore accordingly.
Wave Action: more wave action means the water splashes higher and so the zones occur higher up on
the shore. The strong force produced by powerful wave action will determine not just whether that organism
can remain attached to the rock but also may have an effect on its growth.
Temperature: immersion in water buffers against temperature change. Upper shore species will have to
tolerate the greatest variation in temperature whilst it has least affect in the lower
www.theseashore.org.uk
http://prezi.com/4jp5qyhxrcip/rockyshore-advantages/