Dogwhelk example:
Methods
Results
Analysis
Discussion
Ecoprojects example:
Nucella lapillus
(Dogwhelk) morphology : wave exposure
The shell morphology of Nucella lapillus can be studied in relation to wave exposure.
Possible investigations:
-effect
of wave exposure on shell length, aperture size, shell shape and
shell thickness
Methods :
•hypothesis?
•what
is the independent variable? the dependent variable?
•optimum
sample size? calculate by running mean or standard
deviation?
•sampling methods? random or systematic
sampling?
•how to measure the dimensions of Dogwhelks? the
accuracy of the calipers and the smallest Dogwhelk that it is
possible to measure?
•where do Dogwhelks occur on the
shore? how to locate this zone accurately on different shores?
•how to assess wave exposure?
•minimise
environmental disturbance? specimens should be measured on site
and not removed from the shore and must be returned to their
original location after measuring.
•are food sources
similar on each shore?
•how to minimise environmental
variables? - e.g. if comparing shores of different wave exposure,
sampling needs to be at similar levels on each shore, in similar
areas in terms of barnacle and algal density, and avoiding rock
pools, crevices and overhangs all of which may possibly influence
morphology. Abiotic factors such as temperature, humidity and wind
speed are impossible to control but should also be measured at
each location
• risk assessment ?
•statistical
analysis ?
Measuring Dogwhelk length using calipers
