Coral
reefs
By
Marjorie Henry, Contributor
 |
| An
intensive basketball game between
Ardenne High and Jamaica College'
recently. - Ian Allen Photo |
TODAY,
I will continue to share with you the
answers to questions on coral reefs
that were given in a previous lesson.
You may have noticed that there is similarity
between the questions taken from the
papers for June 2000 and June 2003.
They are both asking for conditions
under which coral reefs thrive. Only,
the number of conditions in each question
varies. These are:
1.
Seawater with temperature between
20 and 30 degrees Celsius. Because
of this, they can only survive in
tropical and
sub-tropical marine environments.
2.
Saline water
3.
Cclear, clean water which free from
sediments;
4.
Shallow water since sunlight must
be able to penetrate to where coral
is growing.
5.
Water that is well supplied with oxygen
and plankton.
The
last question given comes from the
paper of June 2002. It states:
'Describe
the appearance of a fringing reef.'
'The
fringing reef lies near the shore.
It consists of a low platform, separated
from the landmass by a narrow lagoon.
The surface of the platform is usually
flat or slightly concave and its outer
edge drops away steeply to the surrounding
sea floor. The corals grow outwards
from the shore to a depth of about
5.5km, and upwards to low water level,
so that the edge of the platform lies
at approximately the 5.5km line. As
the outer corals grow most freely,
they may reach the surface first,
leaving a shallow channel or lagoon
between the platform and the land.'
Although
you were not asked to draw a diagram
of the fringing reef you can gain
marks should you choose to do one.
Make sure to label it properly. Sometimes
what you miss in the written account
may be shown in the diagram.
As
I complete this topic, here are a
few multiple choice questions I have
constructed. Try to answer them. Choose
the most suitable answer from A, B,
C and D.
1.
Coral reefs survive in sea water where
the temperature is between:
A.
18ºC and 27ºC
B.
27ºC and 35ºC
C.
20ºC and 27ºC
D.
18ºC and 25ºC
2.
Corals grow only in sea depths of
about
A.
55m
B. 75m
C.
30m
D. 15m
3.
Few corals are found close to the
mouths of large rivers because
A.
there is too much sediment.
B. there is too much fresh water.
C. the ideal temperature of the sea
water may not be present.
D.
All of the above.
4.
(i) It lies near the shore.
(ii)
It consists of a low platfor
(iii) It is separated from the land
mass by a narrow lagoon.
The
statements above best describe a/an
A.
fringing reef
B. barrier reef
C.
atoll
D. patch reef
5.
Isolated boulders of coral that form
in shallow water in irregular patches
on the sea bed are called
A.
fringing reef
B. barrier reef
C.
atoll
D. patch reef
6.
The second largest barrier reef of
the world is found off the coast of
A.
Andros in the Bahamas.
B.
Belize
C.
Anegada in the British Virgin Island.
D.
Jamaica
7.
Corals are important for the following
reasons except.
A.
they protect coastlines against wave
action.
B. they stabilise beaches against
erosion
C. they contribute to the formation
of sandy beaches.
D.
they encourage the growth of algae.
8.
The following are marine activities
that will destroy the coral reefs
except
A.
shipping.
B. oil spills.
C.
organic pollution.
D. fishing.
9.
The 'bleaching' of reefs results from
A.
Higher sea temperatures.
B.
Very shallow water
C.
Too much exposure
D.
Too much chemical
These
are the answers:
1.
- C
2. - A
3.
- D
4. - A
5.
- D
6. - B
9. - A
*
Marjorie Henry is Geography teacher
at Glenmuir High School in Clarendon.
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