Human Impacts on Coral Reefs

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Human Impacts on Coral Reefs
Part 1 Natural Stresses and Human Uses
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Factors Correlated with Healthy Coral Reef Growth

• water temperature range 18 29?C
• normal seawater salinity 32 35
• low inorganic nutrient concentrations
  (oligotrophic waters)
• clear, transparent water
• little or no sedimentation
• vigorous water motion

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Natural Sources of Stress on Coral Reefs

• intense storms
• El Niño
• disease
• volcanic eruptions
• predator population explosions
• natural stream and river runoff
• exceptionally low tides

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Storm Wave Damage
Before
After
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Storm Damage
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Normal Wind and Ocean Circulation in the Pacific
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El Niño Conditions
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Sea Surface Temperatures
April 8, 2013
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Impacts of El Niño
Forest Fires
Drought
Bird life impacted
Marine Life Impacted
Coral Reef Damage
Coastal Erosion
Tropical Storm
Floods
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Disease
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Lava Flows
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Crown-of-Thorns Outbreaks
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Stream and River Runoff
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Low Tides
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Some Local Human Impacts

• thermal effluents
• sewage discharges and agricultural runoff
• mechanical damage to reefs
• sedimentation
• destructive resource extraction practices
• introduced species
• loving a reef to death

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Global Human Impacts

• global warming
• ozone depletion
• ocean acidification

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Possible Consequences of Stresses and Impacts on
Corals and Coral Reefs

• outright mortality of coral tissues
• breakage of coral colonies
• bleaching
• diseases
• slower growth
• reduced reproduction and recruitment
• competitive exclusion by other organisms
• increased reef erosion

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Traditional Hawaiian Uses of Coral Reef Resources
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Seaweedslimu
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Hooks andLures
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Octopus Lure
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Fishing Shrineskoa
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Hawaiian Fish Ponds
He'eia fishpond
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Ahupuaa
Ranges from the tip of the mtn to the reef area

1. Upland
2. Plains
3. Ocean

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TheAhupuaa
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Modern Uses of Coral Reefs

• Seafood
• Food Additives and Toiletries
• Health and Medicine Products
• Research and Education
• Jewelry and Art
• Marine Aquarium Specimens
• New Land
• Cement Other Building Supplies
• Shoreline Protection
• Recreation