Download Effects of Climate Change on Marine Ecosystems

Effects of Climate Change on Marine Ecosystems
David Mountain
US CLIVAR Science Symposium
14 July 2008
US GLOBEC Program
Effect of Climate Change on Marine Ecosystems
Process oriented
Physics-Plankton-Fish
Regional Programs
Given climate predictions,
predict ecosystem response
Application to fishery management
Outline:
- Effects of climate change on Ecosystems
- Climate parameters desired by Ecosystems
- Ecosystem-CLIVAR collaborations
Effects of Climate Change on Marine Ecosystems
General:
Warming
- shifting species distributions
- corals – bleaching
ENSO frequency, strength
Low dissolved Oxygen (‘dead zones’)
Loss of sea ice
Ocean acidification
Northwest Atlantic – Gulf of Maine/Georges Bank
44.5
Two major inflows:
44
43.5
Scotian Shelf Water (blue arrow)
(cold, fresh)
43
42.5
Slope water (red arrow)
(warm, saline)
42
41.5
41
40.5
Change in SSW inflow
40
-71
-70.5
-70
-69.5
-69
-68.5
-68
-67.5
-67
-66.5
-66
-65.5
-65
-64.5
-64
NW Georges Bank Salinity Anomaly (0-30m)
Decrease in salinity
during the 1990’s
44.5
44.5
44
44
43.5
43.5
43
43
Increased Scotian Shelf inflow
42.5
42.5
42
42
41.5
41.5
41
41
40.5
40.5
40
-71
-70.5
-70
-69.5
-69
-68.5
-68
-67.5
-67
-66.5
-66
-65.5
-65
-64.5
-64
40
-71
-70.5
-70
-69.5
-69
-68.5
-68
-67.5
-67
-66.5
-66
-65.5
-65
-64.5
-64
Ecosystem Response to Salinity Changes
Georges Bank salinity anomaly
R / Egg Hatched
Haddock 1st Year Survival vs Zoo-X
Zooplankton community structure
(Kane, 2007)
Zoo X-Coordinate
Salinity Anomaly &
Labrador Current Transport
Origin of Low Salinity?
O18 indicates high latitude source
2.8
0.0
3.0
-0.5
Labrador Current
Salinity Anomaly
0.5
3.2
-1.0
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006
Labrador current transport
(one year lag)
Gulf Stream movement
Rossby’s north wall of the Gulf Stream
250
0.5
300
0.0
All part of large-scale response
of the ocean to climate forcing
350
400
-0.5
450
-1.0
-1.5
1992
500
1994
1996
1998
2000
2002
Northeast Pacific
Regime Shifts
1976-1977
Major changes in many
physical and biological
parameters
PDO (Pacific Decadal
Oscillation – 1st mode of SSTa)
(Peterson and Schwing, 2003)
Actually 2 modes of variability:
- PDO
- North Pacific Gyre Oscillation (NPGO)
1st
PDO
mode of SSTa
2nd
NPGO
mode of SSHa
PDO – single gyre
+ Alaska gyre
- California Current
NPGO – two gyres
+ Alaska Coastal Current
+ California Current
(Di Lorenzo et al, 2008)
Di Lorenzo et al. (2008) –
ROMS model of the N. Pacific Ocean,
forced by NCEP winds and heat flux,
with an NPZD for 1950-2004
Response in coastal system to large
scale, regional forcing.
North (48 N)
Upwelling
Delayed Upwelling in 2005
Delay in seasonal production cycle
Adverse affect on young salmon survival
Closure of salmon fishing in 2008
Seasonal timing is important !
(Schwing et al., 2006)
South (33 N)
Important points:
Continental shelves are important (..very important…)
Climate changes elsewhere can be advected into the region
Stratification and vertical processes important
Timing within a season can be important
Decadal Climate Predictions
What ‘Marine Ecosystems’ would want to know:
The ‘usual suspects’ –
Winds
Ocean temperature
Ocean circulation
Precipitation (and river discharge)
The ‘not-so-usual suspects’
Major atmospheric & oceanic indices
(ENSO, PDO, NPGO, NAO, AO, ….)
and …
The “…hard, but critical…” needs –
Resolve continental shelves (horizontal)
(coastal-scale oceanic and met conditions)
Resolve ocean surface layer (vertical)
(upwelling, stratification, convection….)
Other considerations:
“When you’re dead …. you’re dead.”
Variability often more important than the mean
(e.g., salmon & delayed upwelling)
Range, probability distribution for critical parameters
Important for application to decision processes
Ecosystem – CLIVAR Collaborations
Topics areas:
Spatial resolution for shelves – nesting fine scale models
horizontal and vertical resolution
Including biology
coupled bio-physical models
Regions:
Northeast Pacific –
Gulf of Alaska & N California Current
(following Di Lorenzo et al. 2008)
North Atlantic –
Basin-scale changes and fish
‘BASIN’
BASIN: Basin-scale Analysis,
Synthesis, and Integration.
Resolving the impact of climatic processes on
ecosystems of the North Atlantic
basin and shelf seas.
BASIN is an initiative to
develop a joint EU/North
American ocean ecosystem
research program.
(Courtesy of Peter Wiebe, WHOI)
Concerning application of results:
The science is:
this hard
Transition to application is:
this hard
- Involve a ‘manager’ from the beginning
- Keep expectations modest
The End
Low Dissolved Oxygen
‘Dead zones’ – many areas around the world
Land derived nutrients + increased stratification
Off Oregon –
deeper upwelling (lower O2 + nutrients)
stratification
residence time on shelf (?)
Pre-2000
(Chan et al., 2008)
+ 2000-2005 (green)
+ 2006 (red)
Probability …
could be important for management applications
R / Egg Hatched
Haddock Survival
Zoo X - Coordinate
Probability of bad years ahead? Protect the stock
Increase in Oceanic Low Productivity Areas
Surface chl-a < 0.07 mg/m3
Increasing area
Increasing SST
Likely increasing stratification
(Polovina et al., in press)