Effects of Climate Change on Marine Ecosystems David Mountain US CLIVAR Science Symposium 14 July 2008.

Effects of Climate Change on Marine Ecosystems

David Mountain

US CLIVAR Science Symposium14 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

Two major inflows:

Scotian Shelf Water (blue arrow) (cold, fresh)

Slope water (red arrow) (warm, saline)

Change in SSW inflow-71 -70.5 -70 -69.5 -69 -68.5 -68 -67.5 -67 -66.5 -66 -65.5 -65 -64.5 -64

40

40.5

41

41.5

42

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44.5

NW Georges Bank Salinity Anomaly (0-30m)

Decrease in salinity during the 1990’s

-71 -70.5 -70 -69.5 -69 -68.5 -68 -67.5 -67 -66.5 -66 -65.5 -65 -64.5 -6440

40.5

41

41.5

42

42.5

43

43.5

44

44.5

Increased Scotian Shelf inflow

-71 -70.5 -70 -69.5 -69 -68.5 -68 -67.5 -67 -66.5 -66 -65.5 -65 -64.5 -6440

40.5

41

41.5

42

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Georges Bank salinity anomaly

Zooplankton community structure (Kane, 2007) Zoo X-Coordinate

R /

Eg

g H

atch

ed

Haddock 1st Year Survival vs Zoo-X

Ecosystem Response to Salinity Changes

1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006

-1.0

-0.5

0.0

0.5

Sal

init

y A

no

mal

y

3.2

3.0

2.8

Lab

rad

or

Cu

rren

t

Salinity Anomaly & Labrador Current

Transport

1992 1994 1996 1998 2000 2002-1.5

-1.0

-0.5

0.0

0.5

500

450

400

350

300

250

Origin of Low Salinity?

O18 indicates high latitude source

Labrador current transport (one year lag)

Gulf Stream movementRossby’s north wall of the Gulf Stream

All part of large-scale response of the ocean to climate forcing

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)

PDO NPGO1st mode of SSTa 2nd 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.

Delayed Upwelling in 2005

North (48 N)

South (33 N)

Delay in seasonal production cycle

Adverse affect on young salmon survival

Closure of salmon fishing in 2008

(Schwing et al., 2006)

Upwelling

Seasonal timing is important !

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’ –

WindsOcean temperatureOcean circulationPrecipitation (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 modelshorizontal and vertical resolution

Including biologycoupled 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’

Resolving the impact of climatic processes on ecosystems of the North Atlantic basin and shelf seas.

(Courtesy of Peter Wiebe, WHOI)

BASIN is an initiative to develop a joint EU/North American ocean ecosystem research program.

BASIN: Basin-scale Analysis, Synthesis, and Integration.

Concerning application of results:

The science is:

Transition to application is:

this hard

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)stratificationresidence time on shelf (?)

Pre-2000 + 2000-2005 (green) + 2006 (red)(Chan et al., 2008)

Probability … could be important for management applications

Zoo X - Coordinate

R /

Eg

g H

atch

edHaddock Survival

Probability of bad years ahead? Protect the stock

Increase in Oceanic Low Productivity Areas

Surface chl-a < 0.07 mg/m3

Increasing areaIncreasing SSTLikely increasing stratification

(Polovina et al., in press)