US GLOBEC Fundamental Discoveries and Surprises David Mountain

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