Coral Reef Bleaching
PPT By: Andrea Bonde
Location, Location, Location
•Covers over 284,300 square kilometers of Earth’s surface.•No coral reefs on the west coasts of America and Africa because of upwelling and cold currents.
• Biodiversity/Ecosystem•Plethora of animals and
plants live within and around Coral Reefs.• Zooxanthellae are a
very important symbiotic relationship.
Tropical Rainforest of the Ocean
Zooxanthellae•Fixed Carbon
Compounds• Symbiotic Relationship
• Photosynthesis•Energy, enhanced
calcification, elemental nutrient flux.•Provide color
*Coral Reefs provide protection and steady supply of carbon dioxide.*
10 6 zooxanthellae cm 2
Degradation• Anthropogenic:o Overexploitationo Overfishingo Increased
sedimentationo Increased nutrient
overload• Natural Causes:o Violent Stormso Floodingo High and Low
temperature extremes
Ecological Causes• Temperature• Solar Irradiance• Subaerial Exposure• Sedimentation• Fresh Water
Dilution• Inorganic Nutrients
• Xenobiotics• Epizootics
BleachingTwo main causes:
- - Density of zooxanthellae declines- - Photosynthetic pigments in zooxanthellae fall
-- 60-90% of zooxanthellae lost-- 50-80% of zooxanthellae loose photosynthetic pigments
Can it get better?
• If not too severe they can recover in weeks-months. • If zooxanthellae loss is prolonged, the coral host
eventually dies.
Hypothesis3 main hypothesis:
o High temp and irradiance stressors cause enzyme
disruption in zooxanthellaeo Photosynthesis pathways
are impaired at temps above 30*C
o Low and High temps cause cell adhesion dysfunction in
zooanthellae
o This is an adaptive mechanism
Future Hope
Works Cited
Buchheim, Jason. "Coral Reef Bleaching." Marine Biology With Odyssey Expeditions - Tropical Marine Biology Voyages!. N.p., n.d. Web. 12 Feb. 2013. <http://www.marinebiology.org/coralbleaching.
htm>."Coral Bleaching on the Great Barrier Reef." reefED - Educate to keep it Great. N.p., n.d. Web. 12 Feb. 2013. <http://www.reefed.edu.au/home/explorer/hot_
topics/coral_bleaching/coral_bleaching_on_the_great_barrier_reef>."Images." Earn Reward Points and Redeem Them For Free Stuff at Swagbucks.com. N.p., n.d. Web. 5 Feb. 2013. <http://www.swagbucks.com/>.