Transcript AAAS_Griffiths_COML

Understanding global climate change
through new breakthroughs in polar research
Huw Griffiths
[email protected]
Response of polar marine ecosystems
to climate change
• changes in sea-ice
• rising water temperatures
• ocean acidification
Sea-ice change
Colonies:
declining
growing or stable
Parkinson, 2002
Changes in krill population
© I. Arndt, source: AWI
1976 - 2003
Over 2-fold decrease / 10 years
Over 2-fold increase / 10 years
Atkinson et al 2004
Bracegirdle, 2008
Ocean warming
1955-1998
COPE or ADAPT
MOVE
• deeper
• further South
EXTINCTION
+0.05°C / year
Meredith & King 2005
Changes in species composition - 2050
Cheung et al 2009
Southern Ocean Continuous Plankton Recorder
2005
Stress: 0.05
Sea Ice Zone: January
Foraminiferans
2008
2003
1998
2007
2000
2006
1993 2001
Pre-2000:
large zooplankton (krill)
1991
0.5 mm
2004
Post-2000:
small zooplankton (Oithona)
2002
Hosie, pers. com.
Increased CO2  ocean acidification (2100)
calcium carbonate
Orr et al., 2005
© I. Arndt, AWI
• >8000 known species
• 78% of species live on the sea floor
• More than half are only known from the Antarctic
Photographs: J. Gutt/W. Dimmler, © AWI/Marum, Univ. Bremen & M. Scheidat, L. Lehnert; results: Gutt et al (submitted to DSR II)
Climate Change and Benthic Animals
• Food availability
• Invading predators
• Icebergs
• Heat stress
• Acidification
• Species ranges
Range shifts: Where should we look?
Southern Limits
Northern Limits
Barnes et al., 2009
Summary
• Sea-ice changes directly affect the Antarctic marine life
• Warming is expected to change species compositions: invasions, migrations
and extinctions
• Acidification a possible problem for pelagic and benthic species
• Shifts in species ranges will be the first indication of major changes affecting
the seafloor life
For more information about climate change in the Antarctic:
“Antarctic Climate Change and the Environment (ACCE)”
www.scar.org
Acknowledgements
I would like to thank all those who helped in the making of
this talk.
Especially Julian Gutt, Graham Hosie, all those involved
in the SCAR climate change report and my colleagues at
the British Antarctic Survey.