us globec fundamental discoveries and surprises david mountain
TRANSCRIPT
US GLOBECFundamental Discoveries and Surprises
David Mountain
How to Choose?
Fundamental discoveries or findings - integrative, bigger picture Surprises - big, small … whatever…
Apologies
Northwest Atlantic
Salinity anomaly
Low salinity in 1990s – particularly during GLOBEC
Phytoplankton – seasonal timing/abundance
Zooplankton – community structure
Cod & Haddock early life survival consistent with stock abundance
Northwest Atlantic
Salinity anomaly
Gulf ofMaine
GeorgesBank
So where did the low salinity come from?
In flow from Scotian Shelf Gulf of St. Law & north Arctic outflow
So where did the low salinity come from?
In flow from Scotian Shelf Gulf of St. Law & north Arctic outflow
Ecosystem changes are driven by external advectionAnd the response of the internal system dynamics to that forcing
Multi-decade simulation captures system variability
Response to large-scale atmospheric forcing changing the amount and source of upwelling
High NPGO – upwelling from deeper depths (higher nutrients, lower O2)
(Di Lorenzo et al., 2008)
Zooplankton:
Community changes caused by horizontal advection associated with that same forcing (PDO variability)
(Keister et al., 2011)
Zooplankton:
Community changes caused by horizontal advection associated with that same forcing (PDO variability)
Ecosystem changes are driven by external advection (vertical and horizontal)And the response of the internal system dynamics to that forcing
(Keister et al., 2011)
Coastal Gulf of Alaska
Cross-shelf gradients in factors controlling production
Macro- vs micro- nutrients Large vs small phytoplankton Large vs small micro-zooLarge vs small copepods
Different dynamics over short distances
Single quantitative framework (…model…) needs all of the above to represent both regions simultaneously
HNLC
LNHC
(Hinckley et al., 2009)
Coastal Gulf of Alaska
Cross-shelf gradients in factors controlling production
Macro- vs micro- nutrients, Large vs small phytoplankton , Large vs small micro-zooLarge vs small copepods
Different dynamics over short distances
Single quantitative framework (…model…) to represent both regions simultaneously needs all of the above
HNLC
LNHC
Changing climate likely will influence these regions differently with different implications for the local populations
Southern Ocean
Onset of winter ice coverage
2001 - Late
2002 - Early
Cold temperatures in 2002
Low winter krill survival in 2001
- low ice algae concentrations
2001
2002
Winter krill concentration
(Lawson et al., 2008)
Biological ‘Hot Spots’ Regions where predators concentrate
bathymetric, physical and biological conditions combine to provide consistent source of prey
Influx of Circumpolar Deep Water - heat, nutrients higher PP - ties to the ACC
Southern Ocean
(Pinones et al., 2011)
Southern Ocean
Ecosystem sensitive to climate change affecting both local atmospheric forcing and external advection associated with the ACC
Biological ‘Hot Spots’ Regions where predators concentrate
bathymetric, physical and biological conditions combine to provide consistent source of prey
Influx of Circumpolar Deep Water - heat, nutrients higher PP - ties to the ACC
Surprises
3 flavors:
- Unexpected
- Assumed but didn’t find
- Assumed and found
Unexpected
Northwest Atlantic
In 1990s
Haddock early survival increased by x4
Cod early survival decreased by x4
And stock abundance changed similarly
Fishery management to get some credit,
but significant ecosystem component controlling change in stock abundance
Unexpected
California Current System
Low dissolved oxygen Oregon shelf (2002 obs) CALCOFI region (retrospective)
Temporal trend of lower oxygen - adverse biological effects
Upwelling of deeper, offshore waters (lower O2 and higher nutrients) associated with higher NPGO/lower PDO
Shoaling of hypoxic boundary1984-2006
(Bograd et al., 2008)
Unexpected
California Current System
Delayed upwelling in 2005 – Poor survival/condition for salmon and other organisms (major economic consequences)
Unexpected
California Current System
Delayed upwelling in 2005 – Poor survival/condition for salmon and other organisms (major economic consequences)
Timing Matters
Expected but didn’t find:
Northeast Pacific
Expected inverse salmon production in CGOA and CCS – split of west wind drift
Not found – other factors dominant in that variability
Assumed and found
Species Matter
Species specific characteristics (e.g., behavior, nutrition) necessary to explain observations
Assumed and found
Species Matter
Species specific characteristics (e.g., behavior, nutrition) necessary to explain observations
Its not just total carbon (or other currency)
Species Matter
Identified major pathways through which climate change will influence these ecosystems
andthe internal phy/bio dynamics controlling the
system response to that forcing
Summary:
GLOBEC!
Summary
Identified major pathways through which climate change will influence these ecosystems
andthe internal phy/bio dynamics controlling the
system response to that forcing
But history and experience caution humility
These are large, complicated ecosystems
We have learned a lot
But history and experience caution humility
These are large, complicated ecosystems
We have learned a lot
… so the new generation of researchers need have no fear of running out of new, fundamental discoveries to be made.
End