1. BIOTIC FACTORS

2. PLANTS:
Algae Sea grasses
 They are primary producers and provide the basic
food supply for the entire reef ecosystem.

3. ALGAE:
unicellular multicellular
Two main types of
Algae range in size multicellular algae found
on reefs are coralline
algae and calcareous

4. Unicellular algae:
 symbiotic
relationships
 Most corals need
sunlight because
they are colonized
by colorful,
photosynthesizing
algae called
zooxanthellae.
Zooxanthellae

5. Coralline algae
Porolithon Lithothamnio
 n
Produce a “skeleton” of calcium carbonate. Contribute to
reef growth.
 Encrusting coralline red algae grow in rock hard sheets over
the surface of the reef. These rock hard sheets is tough
enough to withstand waves and help keep it from washing
away.

6. Calcareous algae
 do not encrust like
coralline algae, but
grow erect.
 They too produce
calcium carbonate
(limestone).
 The limestone in turn
produces the sand
that is found on the
Halimeda beaches when these
sp. degenerate.

7. Seagrass
 Seagrassbeds are often found in areas where
coral reefs grow.
 Unlike algae, seagrassesare true flowering plants.
manatee shoal
grass grass
Turtle grass

8.  Seagrasses serve as
a habitat and shelter
for reef animals such
as the young or
juveniles of conch
and lobsters.
 These plants also
provide food for
many herbivorous
reef fish.
 The leaves of
seagrass are also a
habitat for very tiny
organisms. Seagrasses have
extensive interwoven
underground
creeping stems with
roots attached.
These stems are
called rhizomes.

9. Animals:
 Coral reefs house at least 25% of life in the ocean.
 Animals use these as a shelter and these also are a
prime source of food for them.

10. Adaptations of the
animals:

11. Adaptations:
Body Shape Adaptive Coloration
Feeding Structures

12. Body shape:
 In the complex coral reef environment however, a premium is
placed upon maneuverability rather than sheer speed.

13. Body shape:
 Thus, many reef
dwelling fishes
have evolved a
body plan that
maximizes their
ability to make
rapid turns and
stop quickly,
highly useful
traits for an
animal
attempting to
avoid predators
in physically
complex habitats.

14. Adaptive Coloration:
 The patterns have different
functions.
 Some unmistakable
contrasting patterns are
used to warn predators that
the fish has venomous
spines or poisonous flesh.
The lionfish, a venomous coral reef
fish, displays vivid warning
coloration.

15. Adaptive Coloration:
gets its name
from a large
dark spot on the
rear portion of
each side of the
body. This spot
is surrounded
by a brilliant
white ring,
resembling an
eyespot.
Four-eyed
Butterflyfish

16. Adaptive Coloration:
 Sometimes they camouflage the fish when the fish
rests in places with the right background.
Gobies
Tassledscorpionfish

17. Adaptive Coloration:
clownfish
 Coloration may also
be used for species
recognition, to
facilitate mating
success.

18. Feeding strategies
 With the unusual variety of prey items available, it is not
surprising that coral reef fish adaptations include highly
specialized jaws, mouths and teeth suited to particular
kinds of food sources commonly found in coral reef
habitats.
Eat algae growing
on reef surfaces,
utilizing mouths like
beaks well adapted
to scrape off their
food.
Parrotfish

19. Feeding strategies
 are
generalized
feeders with
more standard
jaw and mouth
structures that
allow them to
forage on a
wide range of
animal prey
types,
including small Snappers
fishes and
invertebrates.

20.  Anemones are common coral
reef animals, they have a
defense mechanism called
nematocysts.
 Some coral reef dwelling
anemones form close
symbiotic relationships with
other animals, most notably
certain fishes.
 Clownfish have adapted to
shelter among anemone
tentacles. They do so by first
performing a ritualistic "dance"
with a potential host anemone,
lightly brushing up against the
tentacles until a relationship is
established.

21. Human Impact:

22. Coral Bleaching
 What is coral bleaching?

23. Coral Bleaching
 What causes this?
 There are a number
of stresses or
environmental
changes that may
cause bleaching
including disease,
excess shade,
increased levels of
ultraviolet radiation,
sedimentation,
pollution, salinity
changes, and
increased
temperatures.

24. El Niño:
 A change in weather patterns and surface currents,
brings unusually warm water to many parts of the
ocean.
 Widespread coral bleaching and mortality occurs.

25. Sediments
 Fine sediment like silt is very
harmful to corals.
 Even a thin layer of sediment
on the colony surface
smothers the coral
 To remove the sediment,
corals use mucus opposite
opposite in the way they use
it to feed.
 Corals don’t do well in places
where there is a lot of
sediment, unless there is
enough wave action to wash
the sediment away.

26. Sediments
 Human activities that increase the sediment in coral reefs:
 Mining
 Logging
 Construction
 Dredging
This can all lead to erosion.
Also, mangrove trees and seagrasses, which normally act as
filters for sediment, are also being rapidly destroyed. This
has led to an increase in the amount of sediment reaching
coral reefs.

27. Pollution
 Corals are so sensitive to pollution of many kinds. Even low
concentrations of chemicals like pesticides and industrial wastes
can harm them.
 High concentrations of nutrients may harm the reef growth.
 Humans release tremendous amount of nutrients in sewage and
fertilizers that are washed from farmland and carried to the sea.

28. Pollution
 More important, increased
nutrients can alter the
ecological balance of the
community.
eutrophication
 Coral reefs usually grow in
water that is very low in
nutrients.
In such nutrient-poor water, seaweeds do not grow very rapidly and
are kept under control by grazers.
This allows corals to compete successfully for space and light.
When nutrients are added, sea weeds may grow much faster and
shade and choke out the slow-growing corals.

29. Fishing Methods
 Aggressive fishing methods have hurt coral reefs as well,
especially in south and southeast Asia. There, fishermen
dynamite reefs and inject cyanide into the water. Both these
methods stun the fish, making them easier to catch.
 Some estimates indicate that 90 percent of the coral reefs in the
Philippines have been harmed so much that they probably can't
recover.

30. Overfishing:
 This is a problem in many parts of the world. Many people
know the problems cod and salmon fishermen have faced
with a smaller supply of fish. However, overfishing of
certain species near coral reefs can easily affect the reef's
ecological balance and biodiversity.

31.  Here's one example. Grouper is a very popular fish to eat.
However, their removal in some cases has led to an
increase in damselfish, which groupers feed upon.
Damselfish, in turn, create pockets in coral. That's where
the algae the damselfish feed upon grow. In time, these
algae can take over a reef, essentially smothering it.
Overfishing of herbivorous (plant-eating) fish can also lead
to high levels of algal growth.
Damselfish add to the destruction of coral
reef as they create holes in the coral to eat.
Algae then grows in those holes and
eventually smother the coral.