secret cities of the sea

2. Coral
Bleaching
Causes and
Consequences
A CASE STUDY OF ANDAMAN AND NICOBAR ISLAND

3. What is Coral ?
Tiny organism
belonging to
group anthozoa
of phylum
Cnidaria
Secrets a massive
calcareous
skeleton and
collectively
deposits calcium
carbonate to build
colonies
Hard corals
harbor an algae
called
“Zooxanthallae”
Pigment of this
algae gives
extensive color
to coral tissue

4. Coral Polyps
Corals
consists of
small polyps
living together
in a group or
colony
A single polyp
has tube
shaped body
with a mouth
surrounded
by tentacles
Tentacles
helps in
capturing prey
for feeding
During
daytime
polyps are
withdrawn in
their
skeletons
At night
polyps
protrude out
for feeding

5. What is Coral Reef ?
 Concentrated growth of a
variety of corals in a
localized habitat forms
coral reef
 A complex system which
consist of many animals,
including corals and plants

6. Why are they important ?
 Protects coastline from erosion
 Employment to the Fisherman
 Tourism
 Contains most diverse ecosystem of planet
 Provide habitats and shelter for many
marine organisms.

8. Coral Bleaching and causes
Cause of bleaching
 Major change in temperature (increase or decrease)
 Oxygen starvation caused by an increase in
zooplankton due to overfishing
 Increased solar irradiance
 Increased sedimentation
 Bacterial infections

9. Coral Bleaching and causes
 Change in salinity of water
 Elevated sea levels due to global
warming
 Low tide
 Exposed to sun
 Elevated thermal stress resulting
from increased sea surface
temperatures (SST) leads to mass
coral bleaching

11. Consequences of Coral Bleaching
 Decrease in concentration of zooxanthellae causes paling
 Increased concentration results in deepening of colour
 Coral provides protection to algae and algae provides oxygen
and gets rid of waste
 Without zooxanthallae corals are liable to starving
 Coral growth and reproduction are reduced
 Coral becomes increasingly susceptible to disease
 Prolonged bleaching causes death of the coral

12. Corals of Andaman Sea
 Andaman Sea is a home to a total of 177 species of hard
corals belonging to 57 genres
 Area covered by reef is about 2000 sq. km, i.e. 6% of total
island
 Andaman harbors a rich population of corals, molluscus,
fishes etc.
 Most of reefs have luxuriant mangrove vegetation
 Pre-dominant species are Acropora formosa, Acropora no-
bilis, Acropora robusta, Acropora breuggemanni and Acropora
grandis

13. Coral Bleaching in Andaman Sea
 Increased Sea Surface Temperature (SST) caused mass bleaching
effect in 1998, 2002, 2005 and 2010
 Tsunami, 2004 exposed the reefs causing mass bleaching
 Most effected corals were maximum at
 Havelock Island (69.49%)
 South Button Island (67.28%)
 Nicolson Island (56.45%)
 Red Skin Island (43.39%)
 North Bay (41.65%)
 Chidiyatapu (36.54%)

14. Threats to Corals in Andaman
 Natural
 Starfish feeds on Corals
 Use of Rotenone, a poison used for fishing
 Thermal Pollution
 Removal of mangrove forest
 Logging
 Excess use of coral reefs in medical purpose, i.e. for bone
transplant as reefs are rich in calcium
 Removal of reefs to be used in cement industries

15. Government Policies & Law of Action
 “Coastal Regulation Zone Notification 1991” regulates onshore
developmental activities for coastal environments
 CRZN prohibits the collection and trade of corals
 “Wildlife Protection Act, 1972” provides protection for protected areas and
marine species
 Coral Reef Conservation is also included in “Environmental Protection Act,
1972” and the National Conservation Strategy and Policy on
“Environmental Development, 1992”
 Action plan of “Ministry of Environment, Forest & Climate Change” plans
on conservation and management of coral reef resources
 “Indian Coral Reef Monitoring Network” has been framed.

16. THANK YOU
Presented By :
 Abhinav Jha
 Akash Porte
 Amit Kumar Sahu
 Atul Sharma
 Dheeraj Neduthodi
 Sandeep Kumar Sinha
 Saurav kumar Jha
 Sumit Suman

17. Reference
 https://scholar.google.co.in/scholar?hl=en&q=coral+bleaching+in+andaman+ni
cobar&btnG=
 http://eprints.cmfri.org.in/9243/1/24.pdf
 http://www.iisc.ernet.in/currsci/dec252000/1723.pdf
 http://www.qm.qld.gov.au/microsites/biodiscovery/05human-
impact/importance-of-coral-reefs.html