Coral Reefs and Their Problems

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Coral Reefs and Their Problems
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Introduction to Coral Reefs

• Dynamic geomorphological and biological systems
• Can be more than one type of environment
• Best developed in the Indian Ocean and on the
  western margin of the Atlantic and Pacific Oceans
  excluded from the upwelling of cold water on
  the eastern margins
• Seawater temps rarely below 17-18 C or above
  33-34 C
• Prefer average salinities for seawater
  hypersalinity limits them
• Excess sedimentation is also a limitation
  smothers the corals
• High inputs of terrigenous sediment will limit
  their occurrence
• For example, individual reefs along the Great
  Barrier Reef are not well developed with mainland
  rainfalls are high
• At their latitudinal limits, biodiversity drops
• In the Atlantic Ocean, the northern most reefs
  off Bermuda occur due to the Gulf Stream

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Reef Morphology
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Coral Reef Zonation
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Physical and Biological Processes in Time and
Space
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African Dust

• coincidental with the decline of Caribbean coral
  reefs over the past 25 years there has been a
  sharp increase in the transport of African dust
  to the western Atlantic.
• can serve as a substrate for numerous species of
  viable spores, especially the soil fungus
  Aspergillus sydowii, the cause of an ongoing
  Caribbean-wide seafan disease.
• his fungus has been cultured from air samples
  taken during dustfalls in the Virgin Islands, but
  that spores of the fungus are absent when the air
  is clear