Coral Reefs

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Coral Reefs
http//ourworld.compuserve.com/homepages/ mccarty_
and_peters/coral/C-intro.htm
http//tools.coralreef.org/content/ objects/view.a
cs?object_id545
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Importance of Coral Reefs

• 0.2 of worlds oceans
• Habitat for 1/3 of marine fishes
• Habitat for tens of thousands of other animals
• The rainforests of the oceans

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Importance of Coral Reefs

• PROTECTION TO COASTLINES
• ECONOMIC RESOURCES
• BIODIVERSITY
• NATURAL BEAUTY

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Importance of Coral Reefs

• PROTECTION TO COASTLINES
• absorb energy of ocean waves
• reduce erosion of shoreline
• storm damage
• flooding

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Importance of Coral Reefs

• ECONOMIC RESOURCES
• Fisheries for food
• Fisheries for jobs
• Tourism
• Building materials
• Aquarium trade

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Importance of Coral Reefs

• BIODIVERSITY
• The rainforests of the sea
• Genetic diversity
• Pharmaceuticals

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Importance of Coral Reefs

• NATURAL BEAUTY

http//sustainableseas.noaa.gov/missions/ florida2
/background/coralspawning.html
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375 billion in environmental goods and
services Reefs at Risk 1998 (http//www.wri.org/p
owerpoints/reefswww/sld011.htm
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Caribbean reef values(annual net benefits in
2000)

• Fisheries 310 million
• Dive tourism 2.1 billion
• Shoreline protection 0.7-2.2 billion
• Total 4.1-4.6 billion

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REEFS WORLDWIDE ARE THREATENED

• 11 of reefs have been lost
• 16 of reefs severely damaged
• 60 of studied reefs threatened by human
  activities
• No pristine reefs left

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CARIBBEAN REEFS DECLINING

• 1970s 50 coral cover
• Present 10 coral cover
• 80 reduction in coral cover over last 30 years

Gardner et al. 2003 Science 301 958-960
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Threats to coral and coral reefs

• 1) Natural
• 2) Anthropogenic
• of human origin

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Natural disturbances that affect corals and coral
reefs?

• Hurricanes
• Tsunamis
• Volcanoes
• Earthquakes
• Predators competitors
• Bleaching
• Pathogens

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Hurricanes

• Physical damage

• Smothering

http//www.nhc.noaa.gov/ 1989hugo.html

• Freshwater poisoning

• Destruction of other ecosystems upon
• which coral reefs depend

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Tsunamis

• Physical damage

• Erosion

• Possible disruption of reproduction and
  recruitment

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Volcanoes

• Depends upon where volcano occurs

• Heat

• smothering and sedimentation

http//volcano.und.nodak.edu/vwdocs/ current_volcs
/montserrat/montserrat.html
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Earthquakes

• Little direct impact

• Indirect impacts

• triggers tsunamis

• coastal landslides

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Predators

• crown of thorns starfish
• snails
• parrotfish
• butterflyfish

http//www.aims.gov.au/pages/reflib/ cot-starfish/
pages/cot-q07.html
http//www.sanctuaries.nos.noaa.gov/pgallery/pgflo
wer/living/fg_living.html
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Competitors

• algae

http//catbert.er.usgs.gov/african_dust/algae.html
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Bleaching

• Loss of zooxanthellae
• causes
• higher than usual ocean temperature
• sharp changes in salinity
• heavy UV light exposure

http//ourworld.compuserve.com/homepages/ mccarty_
and_peters/coral/Bleach.htm
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http//orbit-net.nesdis.noaa.gov/orad/coral_bleach
ing_index.html
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Pathogens

• Diseases on the rise
• new pathogens (8)
• land pathogens (Aspergillus)
• occurring at all depths
• More susceptible when stressed

http//ourworld.compuserve.com/ homepages/mccarty_
and_peters/ coral/Bbd.htm
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Threats to coral and coral reefs

• 1) Natural
• 2) Anthropogenic
• of human origin

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Anthropogenic threats to coral reefs

• Overfishing
• Development
• Mining and dredging
• Recreation

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Overfishing

• Ecological imbalance

http//www.photolib.noaa.gov/reef/reef2570.htm
http//tools.coralreef.org/content/objects/view.ac
s?object_id545
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Overfishing

• Ecological imbalance

http//catbert.er.usgs.gov/african_dust/events.htm
l
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Overfishing

• Destructive fishing practices

http//oceanworld.tamu.edu/students/coral/coral5.h
tm
http//www.wri.org/indictrs/rrcyanid.htm
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Development

• Sediment ? smothering
• Freshwater input
• Pollutants nutrients (sewage,
  pesticides, fertilizer, heavy metals, pathogens)

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Development
http//www.wcmc.org.uk/marine/data/coral_mangrove/
coral.danger.html
http//ourworld.compuserve.com/homepages/mccarty_a
nd_peters/coral/c-intro.htm
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Development
http//www.sanctuaries.nos.noaa.gov/scied/science/
habitat/influences.html
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Mining for construction materials and dredging

• Destruction of reef structure
• stirs up sediment

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Recreation

• Anchors, boats, flippers, hands, feet
• Kill animal tissue
• Skeleton breakage

http//www.sanctuaries.nos.noaa.gov/scied/science/
habitat/influences.html
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Synergistic effects

• interaction of natural changes human activity
• multiple insults

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Global climate change

• Reduced reef building
• Increase in frequency and intensity of hurricanes
• Increases in bleaching
• Increased in disease

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Synergistic effects
CORAL DOMINATED ALGAL DOMINATED
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JAMAICA
OVERFISHING HURRICANE ALLEN 1980 ACROPORA DIE-OFF
1980S DIADEMA DIE-OFF 1983
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JAMAICA
MORE ALGAE NO GRAZERS LESS CORAL PHYSICAL
DAMAGE ALGAL DOMINATED
SYNERGISTIC EFFECTS
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BUCK ISLAND, ST. CROIX
PROTECTION SINCE 1961 ACROPORA DIE-OFF
1980S DIADEMA DIE-OFF 1983 HURRICANE HUGO
1989 HURRICANES MARILYN/LUIS 1995
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BUCK ISLAND, ST. CROIX
PROTECTION LITTLE OVERFISHING DISEASE PHYSICAL
DAMAGE CORAL DOMINATED