Download Zonation and Adaptations at Rhyd y Creuau

Zonation and Adaptations
at Rhyd y Creuau
Aims:
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To investigate the type, distribution and abundance of organisms inhabiting a rocky shore
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To explain any vertical zonation found by considering abiotic gradients on the shore and
adaptations of organisms present
Objectives:
Tick when achieved
This study will allow us to:
 Understand the environmental gradients present on the rocky shore
 Use systematic sampling in the form of an interrupted vertical belt transect
 Recognise a range of marine organisms common to a sheltered rocky shore
habitat and be aware of their adaptations to the environment
 Identify and explain the zonation trends observed
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Rank from 1 (unknown) to 5 (very confident)
Concept’s we’ll be covering:
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Before
After
Interspecific and intraspecific variation
Interspecific and intraspecific competition
Systematic sampling and belt transect
Structural adaptations
Behavioural adaptations
Hypothesis:
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Justification:
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Location: Penmon Point, Isle of Anglesey
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Sheltered rocky shore on the eastern tip of Anglesey
Adjacent to Puffin Island
Submerged limestone pavement providing a variety of
microhabitats
Inside the proposed Menai Straits Marine Nature
Reserve
Penmon Point
Effects of Climate change?

UK Climate Projections predict an increase of around
2.5°C in average sea-surface temperature by the
2080s
 Warm water species, such as the limpet species
Patella
depressa
are migrating further north
Rocky
shore
ecology
 Spawning times and areas of commercial fish such as
mackerel are showing changes around the UK
Fig. 1: Map showing location of field
site
Rhyd
y creuau
Rocky
Tides and
Shore
abiotic
Ecology:
gradients
Tides and Data Collection
Tides are:
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Tides are caused by the gravitational pull of
the moon and the sun on the ocean.
Every day the rocky shore experiences two
high tides and two low tides. Over a month,
the changing alignment of the moon and the
sun cause a cycle of small tides (neaps) and
large tides (springs).
Vertical movement of tidal waters cause
zones of the rocky shore to be exposed to
the air for differing lengths of time, creating
vertical gradients in abiotic conditions.
Fig. 2: Changes in water levels around mean water height (0m)
Abiotic gradients affected by the tide include:
1.
2.
3.
4.
Method:
Sampling strategy:....................................................................
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Zdf 
Discontinuous, vertical belt transect
Place your first 1m2 quadrat at the top or bottom of the shore (depending on the tide)
Identify the species of algae and animals present, and record their abundance using a
qualitative abundance scale
Place your next quadrat 0.5m lower/higher on the shore, using the gradations on the ranging
poles to measure the height difference
Exposure: Risk of desiccation via increased
exposure to air determines the upper limit
of each species (see Fig. 3).
Competition: Interspecific competition
with faster growing larger species
determines the lower limit of each species.
Loss of mass (%)
[Type a quote from the document or the summary of an interesting point. You can position the text
Rocky Shore Ecology: Algae Adaptations
box anywhere in the document. Use the Text Box Tools tab to change the formatting of the pull
1. Zonation
of brown algae
quote
text box.]
100
Channel
The zonation of brown algae is strongly
wrack
80
influenced by factors including:
Spiral wrack
60
40
Bladder
wrack
20
Serrated
wrack
0
0
12
24
36
48
Kelp
Time exposured to dry air (hours)
Fig. 3: Graph comparing loss of mass from brown
seaweeds
2. Adaptations to low light availability
In cloudy coastal waters, light infiltraion is
limited. Brown algae have two main
adaptations to enable them to survive low
light conditions:
1. Air bladders to lift seaweed thalli
to the surface
2. Accessory pigments to allow
increased use of green and blue
light (e.g. fucoxanthin and
rhodophycin) (see Fig. 4).
Fig 4: Graph showing absorption ranges of accessory pigments
Rocky Shore Ecology: Animal Adaptations
1. Intraspecific adaptation
The flat periwinkle show two distinct
colours as a result of selective predation
2. Interspecific competition
Barnacle species show zonation. Upper limits tend to
be controlled by risk of desiccation, whilst lower
limits are controlled by interspecific competition.
Upper middle shore:
Main predators are birds. Brown
periwinkles are more likely to ecape
predation, camoflagued on the fucoids
Lower middle shore:
Main predators are fish. Yellow
periwinkles are more likely to escape
predation, camoflagued against the light
filtering through the Fucoids
Where two morphs are found within the
same species this is known as a genetic
polymorphism
Fig. 5: Distribution of barnacle species on the rocky shore
Zonation of life on the rocky shore:
Lower Shore
Middle Shore
Upper Shore
Splash
Organisms, adaptations and biotic gradients
Abiotic factors