1. Coral Reefs
Oasis of the Sea
Coral Reefs

2. Coral Reefs
Why are coral reefs unique?
Coral Reefs

3. Coral Types Hermatypic Ahermatypic
Both groups belong to the phylum Cnidaria
Coral Reefs

4. Coral Structure & Anatomy
Coral Reefs

5. Coral Reproduction
Coral Reefs

6. Coral Nutrition
Zooxanthellae provide nourishment for the coral through photosynthesis
Polyps eat and are voracious predators on zooplankton
Coral Reefs

7. Other Reef Builders Corals do not build a reef alone
Coralline algae produces a skeleton of calcium carbonate that grows in hard sheets on the surface of the reef
Coral Reefs

8. Conditions Needed For Reef Growth
Temperature
All reefs are bounded by the 20 C isotherm
Optimal reef development occurs at 23-25 C and up to 36-40 C
Water temperature that is too warm will cause coral bleaching
The zooxanthellae is expelled from the coral
El Nino events cause massive bleaching in some areas ( )
Coral Reefs

9. Coral Reefs

10. Light
Zooxanthellae dependent corals do not develop in water deeper than meters
This limitation occurs due to photosynthetic requirements
Coral Reefs

11. Salinity and Sedimentation
Corals are intolerant of salinities ranging outside of ppt
Human activities; dredging, mining, logging, and construction increase the amount of sediment and freshwater runoff
Sedimentation clogs feeding mechanism and reduces the penetration of sunlight
Coral Reefs

12. Wave Action Usually not a problem due to hard coral exoskeletons
Benefits: renews oxygen, removes sediment, brings in new plankton
Reefs cannot tolerate extended periods of exposure to air
Coral Reefs

13. Fringing Reefs
Coral Reefs

14. Barrier Reefs
Coral Reefs

15. Atoll Reefs

16. Coral Reef Ecology
Coral reefs are easily the richest and most diverse of all the oceans ecosystems
How do these animals interact with each other, what role do they play in the ecosystem?
Reefs are found in areas that are usually poor in nutrients, lack phytoplankton and other means of primary production
The question is how do these habitats thrive in these nutrient poor waters?
Coral Reefs

17. Nutrient Cycling
Coral Reefs

18. Competition Space is a limiting resource
Sessile animals compete for space in interesting ways
Fast growers shade out their neighbors
Some use mesentery filaments or sweeper tentacles to sting neighbors
Coral Reefs

19. Predation and Grazing Predation Grazing
Grazers are very important to the ecosystem since they help keep the algae in check
Coral Reefs