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Ecoprojects
Fieldworks
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Dogwhelk example:
Methods
Results
Analysis
Discussion
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Ecoprojects example:
Nucella lapillus
(Dogwhelk) morphology : wave exposure
Discussion
•are Dogwhelks significantly
larger overall on sheltered or exposed shores?
•does
exposure result in a Dogwhelk with a relatively larger or smaller
foot (or aperture)?
•what are the advantages of a larger
foot size?
•Dogwhelks do not have a planktonic part to
their lifecycle but instead lay eggs that hatch into miniature
adults. This means if there is no movement of individuals from
other areas and the populations can become genetically isolated.
Selective pressure can therefore lead to differences between
shores.
•smaller shells would present a smaller surface
area to the moving water, a larger foot area (aperture) might
maximise adhesion to the rock's surface. There is little sea spray
on sheltered shores which might lead to greater desiccation . An
elongated shell would be able to store relatively more
water.
•crabs, particularly the Common shore crab
(Carcinus maenas) are more common on a wave sheltered
shore. What type of shell would reduce predation by crabs on the
Dogwhelk?
•how does your investigation relate to previous
work carried out in this field. Cite some references relevant to
your project and compare or contrast your data to previous
investigations.
Evaluation
•accuracy of measurement?
•was
sample size adequate?
•were there any anomalies in your
results?
•were there any limitations? problems?
•what
other parameters could you have measured to improve your
investigation and to back up some of your results? e.g. is shell
thickness affected by exposure?
•is the assumption of a
large aperture indicating a large foot size valid?
•are
food sources similar on the shores compared?
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