Biodiversity: Present, Past, Future? Nancy Knowlton National Museum of Natural History
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Transcript of Biodiversity: Present, Past, Future? Nancy Knowlton National Museum of Natural History
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Biodiversity:Present, Past,
Future?
Nancy Knowlton
National Museum of Natural History
Smithsonian Institution
Marine Biodiversity CrisisNatural Disturbances
+People
CO2
NutrientsToxicsSedimentsAliens
Anything Longer or Taller than 5 cm
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
22 dead coral heads ~ 20% of total European diversity
DISCOVERY BAY, JAMAICA IN 1975
GONE
and not just in Jamaica
Caribbean-wide:80% decline in 30 years
Pacific on same trajectory
July 2008
At Risk
?
OK
Business as usual = no reefs by 2050
Remember: CO2 lasts for centuries in the atmosphere
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Scenarios for the future
Pristine Human Dominated Wasteland
Bio
dive
rsit
y an
d E
cosy
stem
Fun
ctio
n?
?
Where is what being lost?
Synergies between
coral cover and
diversity
fish
Jackson et al. 2001
PRISTINE DISTURBED
Overfishing and Trophic CascadesEntire food webs are affected
Jellyfish & Bacteria(aka “the rise of slime”)
X
X X
Without managementeven 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
Bacteria
Viruses
Othermicrobes
Altered Communities
Bottom cover
Increasing human influenceIncreasing human influence
Reduced Resilience
Increasing human influence
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 globallyMPAs alone are not enough
?Provides Insurance, Buys TimeProvides Insurance, Buys Time
Short Term/Local Scale:
Control fishing pressureImprove water quality
Longer Term/Global Scale:
Reduce CO2 emissions
Resilience Strategies
“First let’s concentrate on water. Then we’ll worry about krill”
If We Fail….