Science Grade 5 Coral Reefs

1. Corals
(Marine Animals of Phylum Cnidaria)
Science V

2. The Invertebrates
1. Phylum Porifera (Sponges)
2. Phylum Cnidaria (Hollow-bodied animals)
3. Phylum Platyhelminthes (Flatworms)
4. Phylum Nemathelminthes (Roundworms)
5. Phylum Annelida (Segmented Worms)
6. Phylum Mollusca (Soft-bodied animals)
Review

3. 7. Phylum Echinodermata (Spiny-skinned
animals)
8. Phylum Arthropoda (Multiple-legged
animals)
a. Class Crustacea (Crustaceans)
b. Class Chilopoda (Centipedes)
c. Class Diplopoda (Millipedes)
d. Class Arachnida (Arachnids)
e. Class Insecta (Insects)
Review

4. Look at the picture. Can you tell what this is?
Motivation

5. The tiny sea animals know as true corals
often form colonies that are attached to rocks
or reefs. The individual animal stays here
during its lifetime; after it dies, the skeleton
remains. New corals grow above them. This
process goes on and on until large buildings of
corals are formed. The coral building is called
coral reef.
Presentation

6. When coral colonies grow close to the
shore they form the fringing reefs. Fringing
reefs move slowly away from the shore. This is
because a coral reef grows mainly towards the
ocean side. At this side the ocean waves bring
the corals water and food.
As the fringing reef continues to grow
oceanward, it becomes a barrier reef. An
example of a barrier reef is the Great Barrier
Reef of Australia (2000 km long 150 km wide)

7. Corals (Marine Animals of Phylum Cnidaria)
Stony corals are reef-building species.
Coral reefs are built when the exoskeletons of
corals, composed of calcium carbonate or lime,
accumulate in large quantities. This large
accumulation happens as the limy exoskeletons
of one generation of stony corals are secreted
on the exoskeletons of the past generation.
Corals can take millions of years to form a reef.
Presentation

8. Factors that Contribute to Reef Formation
Aside from corals, other organisms with
skeletons composed of calcium carbonate (or
lime) contribute to the building of depositing
limestone sheets over the surface of the reefs.
As organisms living in canal reefs die, their
bodies are broken down by grazing organisms
like fish and sea urchin as well as natural forces
like wave action. Their limy skeletons settle and
contribute to the structure of the reef.
Presentation

9. Importance of Corals
Coral reefs are one of the most beautiful
and colorful natural resources on Earth. Did
you know that the Philippines is one of the
countries with the most extensive coral
systems in the world? Some of them can be
found in Palawan, Sulu, and Southern
Mindanao.
Presentation

10. Coral reefs are important due to several
reasons:
1. Coral reefs are the natural habitats for many
sea animals like sponges, mollusks,
crustaceans, and echinoderms.
Some of these animals graze on algae that
grow on the surface of the reef, others feed on
smaller animals. All in all, the organisms that
inhabit coral reefs participate in the complex
network of eating and being eaten.
Presentation

11. 2. Coral reefs are the breeding ground of fishes
and other forms of marine life.
Coral reefs provide environmental
conditions that favor the growth and
development of young sea animals.
3. Coral reefs provide rich sources of marine
food.
Coral reefs provide an abundant supply of
fish, shrimp, crab, and other edible marine
animals.
Presentation

12. 4. Coral reefs serve as a rich recreational area
and provide entertainment to people who
enjoy exploring underwater marine life.

13. 5. Calcium carbonate that is found in coral
reefs is an important building material.
6. Coral reefs protect coastlines from strong
waves and water currents.
Presentation

14. Factors Contributing to Destruction
1. Dynamite Fishing
A single explosion can kill all the fishes in
the area. With decreasing number of cnidaria,
there will be less corals.
2. Muro-ami Fishing
Muro-ami fishing uses movable net bag
that is spread around the reefs. The young
fishermen (ages 9-16) hammer the corals with
rocks or other objects. This drives the fishes

15. out of their homes and into the waiting nets.
Muro-ami fishing leaves behind a coral reef
completely destroyed.
With no regard for its beauty and
economic value, Muro-ami fishing contributes
to the destruction of the entire coral reefs.
3. Pollution of seawater destroys all marine life
forms.

16. Describe ways of saving the coral reefs.
Application

17. SAVING
THE
CORAL
REEFS
GOOD
FISHING
PRACTICES
REFOREST
RATION
INDUSTRIAL
AND
AGRICULTURAL
WASTES
CONTROL
CONTROLLED
LOGGING
ACTIVITIES
SEAGRASS
BED
PROTECTION
SILTATION
CONTROL

18. How Can We Save our Beautiful Coral Reefs?
1. Our government, through the Bureau of
Fisheries, provides and implements
regulations regarding collection of coral but
enforcement is difficult.
2. Prohibit the destruction of sea animals by
banning dynamite fishing.
3. Strict rules regarding the discharge of
pollutants into the sea must be
implemented.