Coral Reef Ecology

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Coral Reef Ecology
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• Importance of coral reefs
• Fisheries
• Subsistence
• Recreational
• Commercial
• Tourism
• Costal erosion
• Ocean research

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• Questions about coral reefs
• What are they?
• How are reefs formed?
• Why are reefs so diverse?
• Why are reefs declining?

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Coral reefs are an association of large
numbers of plants and animals living together in
tropical areas primarily composed of coral 

• Secretes of corals success
• simple polyp morphology
• colony formation
• external skeleton
• mutualistic zooxanthellae

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polyp stage- simple structure like
anemone composed of two layers- epidermis and
gastrodermis tissue Repro binary fission-
asexual form genetically identical individuals
form colony Sexual- gametes
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Colonial Formation
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• Calcareous skeleton provides
• support
• protection
• allows for light to enter

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Symbiotic relationship with zooxanthellae
Zooxanthellae in gastrodermis
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Mutualism

• Corals receive
• Provided with food
• Wastes are removed
• Helps secrete skeleton
• Speeds up rate of skeleton formation

• Zooxanthellae receive
• Safe place to live
• Available sunlight
• Nutrients from coral waste

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• How are reefs formed?
• Formed by accumulation of coral skeletons,
  coralline algae, and reef sediments over a long
  period of time
• Volcano- birth of reef
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• Why are coral reefs so diverse?
• They provide light, food and shelter to a wide
  variety of marine organisms
• Feeding relationship in a reef community are
  called a food web
• Different species have different roles in a reef
  community

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Coral reef community interactions

• Producers
• coral-zooxanthellae symbiont
• coralline-algae, seaweeds

• Consumers
• herbivores- plant eaters
• corallivores- coral eaters
• carnivores- animal eaters
• top predator- no one else eats 

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• Hawaiian corals- 6 common species (1st 3- 90 of
  species found mostly shallow)
• cauliflower
• lobe
• finger
• rice
• rubber
• brain
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• surgeon fish- eats seaweed- controls algae growth
• parrotfish- creates sediment
• urchins- graze seaweed
• butterfly fish eat coral
• triggerfish- microcarnivore (wide diet- seaweeds,
  coral, urchins)
• moray eels- macrocarnivore- fishes, snails
• sharks- top predator- control abundance of
  organisms below them