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Biodiversity: Present, Past, Future? Nancy Knowlton National Museum of Natural History Smithsonian Institution
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Marine Biodiversity Crisis Natural Disturbances + People CO 2 Nutrients Toxics Sediments Aliens Anything Longer or Taller than 5 cm
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1 - 9 million reef species in total (?) 1/4 of all marine species (?) Most are rare Coral Reefs : “Rainforests of the Sea” ~1000 coral species
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22 dead coral heads ~ 20% of total European diversity
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DISCOVERY BAY, JAMAICA IN 1975 GONE and not just in Jamaica Caribbean-wide: 80% decline in 30 years Pacific on same trajectory
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July 2008 At Risk ? OK
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Business as usual = no reefs by 2050 Remember: CO 2 lasts for centuries in the atmosphere Scenarios for the future
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Pristine Human Dominated Wasteland Biodiversity and Ecosystem Function ? ? Where is what being lost?
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Synergies between coral cover and diversity fish
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Jackson et al. 2001 PRISTINEDISTURBED Overfishing and Trophic Cascades Entire food webs are affected Jellyfish & Bacteria (aka “the rise of slime”) X X X
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Without management even a few people can have substantial impacts on coral reefs through fishing and sewage Kingman (US) pop. 0 Palmyra (US) pop. ~10 Tabuaeran (KR) pop. ~ 2000 Kirimati (KR) pop. ~ 6000 Hawaii Australia Time Machine Research
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Bacteria Viruses Other microbes Altered Communities Bottom cover Increasing human influence
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Reduced Resilience Increasing human influence
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California Condor Conservation Strategies Not a Realistic Option for Most Species, What Do We Do?
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Build Ecological Resilience Reduce Local Impacts so Reefs Can Recover from Impacts We Can’t Control 150 years
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Marine Protected Areas as One Tool for Building Resilience Great Barrier Reef, Australia Two of the World’s Largest MPAs Protect Coral Reefs But less than 2% of reefs are protected globally MPAs alone are not enough
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? Provides Insurance, Buys Time Short Term/Local Scale: Control fishing pressure Improve water quality Longer Term/Global Scale: Reduce CO2 emissions Resilience Strategies
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“First let’s concentrate on water. Then we’ll worry about krill” If We Fail….
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