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