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Human Impacts on Coral Reefs

Human Impacts on Coral Reefs. Part 3 Global Impacts. The Greenhouse Effect. atmosphere. 25%. reflected. 5%. 25%. 45% reaches the surface. Human-Produced Greenhouse Gases. Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O) Ozone (O 3 ). Natural Phenomena. Direct evidence.

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Human Impacts on Coral Reefs

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  1. Human Impacts on Coral Reefs Part 3 Global Impacts

  2. The Greenhouse Effect atmosphere 25% reflected 5% 25% 45% reaches the surface

  3. Human-Produced Greenhouse Gases Carbon Dioxide (CO2) Methane (CH4) Nitrous Oxide (N2O) Ozone (O3)

  4. Natural Phenomena Direct evidence Volcanic emissions? Sea spray? Upper atmosphere research satellite sunspots

  5. Greenhouse Gases

  6. Carbon Dioxide & Temperature Year

  7. Possible Impacts of Global Warming on Corals and Coral Reefs • bleaching • eustatic sea level rise creating more growth room for reefs • increased carbon dioxide may increase reef primary productivity • increased storm damage • changes to patterns of terrestrial runoff • changes to ocean circulation patterns

  8. Effect on Marine Life • Phytoplankton bloom due to light and temperature cues • Changes will impact food web • Hypoxia may result

  9. Effect on Fisheries • Migrations are in response to temperature • May impact fisheries

  10. Effect on Corals • Coral bleaching • Leads to loss of habitat and food for reef- dependent species

  11. Global Bleaching (2002) none low moderate severe severity unknown

  12. Some causes of coral bleaching • Unusually high or low temperatures • Unusually high or low salinity • High amounts of visible or ultraviolet light • Sedimentation • High levels of nutrients (sewage, etc.) • High levels of toxins (pesticides, etc.)

  13. Currents Currents • Oceanic conveyor belt may change ocean currents • Currents carry plankton • Bring food and oxygen • Distribute eggs and larvae • Remove wastes and pollutants

  14. Salinity Salinity • Animals have a narrow range of tolerance • Glacial melting inputs lots of freshwater

  15. Ocean Acidification Acidity • CO2 makes water acidic • Corals and other calcium carbonate species can’t make skeleton • Impact on plankton development impacts food web

  16. Temperature Temperature • Higher temperature results in less O2 • - Results in hypoxia • Ice melting leaves no resting/hunting areas for polar bears • Antarctic Krill impacts food web

  17. Invasive Species Invasive Species • Algae smothers coral • Invasive species out-compete natives

  18. Weather Events Weather Events • More severe weather patterns • El Niño • Hurricanes • Mudslides • Forest Fires • Drought

  19. Sea Level Rise Sea Level Rise

  20. Sea Level Rise

  21. Projected Sea Level Rise

  22. Effects of Sea Level Rise on Human Populations Sinking Islands

  23. Effects of Sea Level Rise on Human Populations Sinking Islands Kiribati Tuvalu

  24. Artificial Islands a Solution?

  25. Consequences: Worst Predictions 4-6o F increase (2-3oC) in 20-30 years End of the Ice Age: 1oC per 500 years Now: 1oC per 10 years Highest temperature in 2 million years

  26. Temperature Rise Melting: glacier & polar ice cap 11% in last 100 years Sea temperature increase: 2oF increase = 2 ft (0.6 m) rise

  27. Global Warming Global Warming

  28. Global Warming Click on link http://www.glaciers.pdx.edu/Projects/LearnAboutGlaciers/ROMO/BasicsIceAges.htm l

  29. Ice Ages in Hawai`i

  30. Global Warming 100 m sea level rise

  31. Global Warming 100 m sea level rise

  32. 1 Meter Sea Level Rise Waikiki http://www.soest.hawaii.edu/HMRG/FloodingOahu/index.php http://www.soest.hawaii.edu/coasts/sealevel/waikiki.html

  33. Sea Level Rise • Destroys coastal habitat (e.g. salt marshes, mangroves) • Destroys human property • Increases pollution • Decreases freshwater supply

  34. Ozone Depletion

  35. Ozone (O3) in the Atmosphere

  36. Absorption of Ultraviolet Radiation by the Earth’s Atmosphere

  37. 2 Ultraviolet Radiation “A threat to the continuation of life” Infrared (IR) Visible UV Humans: DNA damage Cancer Crops: Productivity decrease Ocean plants: Death?

  38. Ultraviolet Radiation stratospheric ozone layer UV destroy CFCs: refrigeration electronics foam packaging spray propellants ‘96: CFC decrease noticed 2006: stabilization?

  39. 400 Ozone blocks UV 300 Total ozone (Dobson units) 200 100 0 1950 1960 1970 1980 1990 2000 2010 Antarctic Total Ozone Trend

  40. Size of the Antarctic ozone hole Average Area: millions sq km North America 30 20 Antarctica 10 0 2001 1979 Prediction: 50 years to return to 1980 size

  41. Oct. 1979

  42. 8.2 million miles2 Sep. 2012

  43. Naturally Occurring Ozone Destroying Chemicals • nitrogen from soils and the ocean • hydrogen from atmospheric water vapor • chlorine from the ocean

  44. Human Produced Ozone Destroying Chemicals • chlorofluorocarbons • jet aircraft exhaust • other industrial chemicals

  45. Human Produced Ozone Destroying Chemicals

  46. Effects of UV on Living Things • damage to DNA resulting in mutations • damage to other biological molecules • proteins: enzyme inactivation • lipids: disruption of cell membranes and membrane transport systems

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