CORAL REEFS

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CORAL REEFS
To this
From this
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AN IMPORTANT ECOSYSTEM

• Coral reefs are as biodiverse as Tropical
  rainforests with 5000 tonnes of new growth per
  km² per year.
• It is an ancient ecosystem which has not evolved
  for millions of years.

But A FUSSY ECOSYSTEM!

• Coral reefs need the following conditions to
  survive .
• Sea water at a temperature of 25ºC or more
• Depth of water must be less than 100m
• Water must be sediment-free.
• Changes in salinity can affect the reefs.

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LOCATION OF CORAL REEFS
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A few hardy species temperatures and salinity
high and can dry out at low tide.
Growth of coral fastest food, water-borne
nutrients and oxygen.
Mobile corals that regenerate poorly, have high
numbers of larvae and a high death rate.
Atolls dead coral islands form when coral is
exposed e.g. Maldives
5m
Reef limestone dead and compacted organic
remains of coral, algae etc.
Large stationary animals slow growing and long
living.
Coral here has adapted to turbulent water
colonies break up but fragments survive.
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Threats to coral reefs
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How bad are these threats?
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• CASE STUDIES
• Great Barrier Reef
• Florida Keys
• Tahiti, Pacific Ocean
• Sinai Peninsula, Red Sea
• Cebu, Philippines

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• Florida Keys
• Corals covered in slime but unsure why.
• Phosphorus and nitrates from farming and sewage
  causes eutrophication.
• Draining the everglades has led to sediment
  increase.

THREATS

• Great Barrier Reef
• 1960-70s threatened by oil spills.
• Nutrients from farmland affecting structure of
  reef
• Crown of the Thorn starfish affected 1 in 5 reefs
  in 1980s.

• Cebu, Philippines
• Fish makes up 50 60 of the SE Asian diet and
  the population has doubles to 68 million in last
  30 years leading to overfishing.
• Dynamite fishing are illegal but common.
• International marine trade poaches fish and coral
  for aquariums (eg. Florida). Cyanide is used to
  make fish drowsy before capture.
• Rubbish

• Tahiti
• Changes in local sea temperatures has led to
  coral bleaching.

• Sinai Peninsula
• Tourism has increased to over 800,000 tourists
  per year and the increase in diving and boat
  activity is damaging the reef.

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Management strategies

• Florida Keys
• Removal of all coral is prohibited and waters are
  heavily policed.
• Educational parks
• Coral reef sanctuaries
• (NB. Florida imports coral to sell from
  Philippines)

• Great Barrier Reef
• 95 is now a marine park
• Permits are restricted to dive companies are
  given an area permanently so encouraged to look
  after it.
• Some companies like Quicksilver are employing
  marine biologists as dive guides.

• Cebu, Philippines
• Locals agree to protect 0.5km of reef as a
  sanctuary where fishing is banned.
• Fish numbers increase and spread to other areas
  increasing fish catches.
• Coral reproduces through larvae which move down
  current allowing these source sanctuaries to
  populate other areas.

• Sinai Peninsula
• Multiple use National Park both land and sea
• Supported by EU who provided 50 of funding