Human Impacts on Coral Reefs Part 3 Global Impacts Part 3 Global Impacts

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

Human-Produced Greenhouse Gases Carbon Dioxide (CO 2 ) Methane (CH 4 ) Nitrous Oxide (N 2 O) Ozone (O 3 )

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

Greenhouse Gases

Carbon Dioxide & Temperature Year

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 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

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

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

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

Global Bleaching (2002) none low moderate severe severity unknown

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.)

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

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

Acidity CO 2 makes water acidic Corals and other calcium carbonate species can’t make skeleton Impact on plankton development impacts food web Ocean Acidification

Temperature Higher temperature results in less O 2 - Results in hypoxia Ice melting leaves no resting/hunting areas for polar bears Antarctic Krill impacts food web Temperature

Invasive Species Algae smothers coral Invasive species out-compete natives Invasive Species

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

Sea Level Rise

Projected Sea Level Rise

Effects of Sea Level Rise on Human Populations Sinking Islands

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

Artificial Islands a Solution?

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

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

Global Warming

l Click on link Global Warming

Ice Ages in Hawai`i

100 m sea level rise Global Warming

100 m sea level rise

1 Meter Sea Level Rise Waikiki

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

Ozone Depletion

Ozone (O 3 ) in the Atmosphere

Absorption of Ultraviolet Radiation by the Earth’s Atmosphere

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

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

Antarctic Total Ozone Trend Total ozone (Dobson units) Ozone blocks UV

Size of the Antarctic ozone hole Average Area: millions sq km North America Antarctica Prediction: 50 years to return to 1980 size

Oct. 1979

Sep million miles 2

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

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

Human Produced Ozone Destroying Chemicals

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 damage to DNA resulting in mutations damage to other biological molecules –proteins: enzyme inactivation –lipids: disruption of cell membranes and membrane transport systems

Corals and UV Radiation decreased growth decreased rates of calcification transplantation experiments (deep corals brought to the surface) demonstrate corals may be UV-sensitive (exhibit bleaching and increased mortality) coral sperm appears to be UV-sensitive (note spawning normally takes place at night) decreased growth decreased rates of calcification transplantation experiments (deep corals brought to the surface) demonstrate corals may be UV-sensitive (exhibit bleaching and increased mortality) coral sperm appears to be UV-sensitive (note spawning normally takes place at night)