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Marine
Ecology
Analysis
of
Data recorded
Activity 4
Exercise 1
Zoologists and botanists use specialised keys to identify specimens of fauna and flora to species
level. Use the field keys provided to confirm identification of specimens to species level for:
a green seaweed
two types of brown seaweed
two types of red seaweed
a crustacean
a bivalve mollusc
two types of gastropod mollusc
a bryozoan
Exercise 2
A group of marine scientists conducted a survey of intertidal seaweeds on a rocky shore. They
surveyed the shore using 5 transects. For each transect they used 3 quadrats to sample the upper
shore, 3 quadrats to sample the middle shore and 3 quadrats to sample the lower shore. The scientists then calculated the mean percentage cover for each seaweed relative to each shore zone. They
then prepared kite diagrams and histograms of their results.
(a) The data sampled for Spiral Wrack in Transect 1 of the scientists’ survey is given below.
Calculate the mean percentage cover of the Wrack for each shore zone, ie. for the upper, middle
and lower shores.
Transect 1
Lower shore
Spiral wrack
Quadrat 1
Quadrat 2
Quadrat 3
0
0
0
Middle shore
Upper shore
20
15
17
50
30
60
If you have gathered you own data on the shore then us this data to calculate the mean
percentage cover of a seaweed for each shore zone
Marine Biodiversity and Ecosystem Functioning EU Network of Excellence
Sustainable development, global change and ecosystems
GOCE-CT-2003-505446
Marine
Ecology
Analysis
of
Data recorded
Activity 4
Exercise 2 (b)
The mean percentage cover of the main seaweed species sampled by the scientists for each shore
zone is given below. Prepare a kite diagram, demonstrating the distribution, abundance and
zonation of the algae on the seashore.
Transect 1
_____________________________________________________________________
Seaweed species
Lower shore
Middle shore
Upper shore
_____________________________________________________________________
Gutweed
(Enteromorpha sp.)
Sea lettuce
(Ulva sp.)
Channelled wrack
(Pelvetia canaliculata)
Spiral wrack
(Fucus spiralis)
Bladder wrack
(Fucus vesiculosus)
Egg wrack
(Ascophyllum nodosum)
Saw wrack
(Fucus serratus)
Kelp
(Laminaria digitata)
Dillisk
(Palmaria palmata)
Irish Moss
(Chondrus crispus)
0
0
30
0
5
10
0
0
40
0
17
47
5
10
0
0
20
0
20
10
0
30
0
0
10
0
0
20
0
0
________________________________________________________________
An example of a kite diagram for 3 species along the shore (A quadrat was sampled here every 0.5m drop in height)
Marine Biodiversity and Ecosystem Functioning EU Network of Excellence
Sustainable development, global change and ecosystems
GOCE-CT-2003-505446
Marine
Ecology
Analysis
of
Data recorded
Activity 4
Exercise 3
Prepare a histogram depicting mean percentage cover for each seaweed sampled on the lower
shore.
Exercise 4
Prepare a poster on marine intertidal biodiversity. The poster should contain examples of fauna
and flora that you observed on the rocky shore in your locality. Consider the following in your
display:
(a) How organisms are adapted to life on the rocky shore, eg. why does the channelled wrack
have channels on its fronds? Why does the bladder wrack have bladders (or air sacs)? Why
can’t we see the sea anemone’s tentacles when it is out of the water?
(b) How adaptations affect distribution and zonation of species on the shore, eg. why do red seaweeds live on the lower shore rather than the upper shore? Use the kite diagrams and histograms from Exercise 2 and 3 to demonstrate how zonation on the seashore can be studied using
an intertidal survey.
(c) How organisms are affected by abiotic factors on the rocky shore? eg. Why were there more
brown wrack seaweeds on the sheltered shore? Think about the differences in abiotic factors
experienced by animal and plant communities between exposed and sheltered shores.
Marine Biodiversity and Ecosystem Functioning EU Network of Excellence
Sustainable development, global change and ecosystems
GOCE-CT-2003-505446