Climate and carbon impacts on productivity, chemistry and...

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Climate and carbon impacts on productivity, chemistry and invasive

species in the Great Lakes Galen A. McKinley

University of Wisconsin - Madison Atmospheric and Oceanic Sciences

Nelson Institute Center for Climatic Research

17 January 2013

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Thanks to

• Val Bennington, UW-Madison • C. Mouw, N. Urban, M. Auer, Michigan Technological Univ. • J. Kitchell, UW-Madison • McKinley Research Group – J. Phillips and D. Pilcher • Funding from the National Science Foundation;

CCR/Climate People and Environment Program; Sea Grant

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Biogeochemistry is elemental cycling and flux between reservoirs, and interactions with lower food web

Sarmiento and Gruber, 2006, fig 4.4.1

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Physics sets the stage

Talley et al., 2011, fig 9.1; NASA image

Satellite Chlorophyll

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Physics sets the stage

Movie of modeled tracer advection in Lake

Superior shown here (MITgcm.Superior)

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Together, physics and biogeochemistry are the infrastructure on which ecosystems depend

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New York Times, 8 Jan 2013

Climate change has arrived

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The Great Lakes are feeling the heat

Desai et al. 2009, Austin and Colman 2007

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Impacts of climate change and other stressors on ecosystems? Non-linear effects? Need to understand physics, biogeochemistry.

Allan et al., 2013

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Further, warming is due to anthropogenic CO2

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What is the Great Lakes role in the carbon cycle?

IPCC AR4, 2007, Figure 7.3

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Advancing understanding of Great Lakes biogeochemistry and physics

1. Carbon budget of Lake Superior 1. Energy sources for Diporeia in Lake Superior

2. Warming and the Sea Lamprey in Lake Superior 1. Ocean Acidification in the Great Lakes

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14 Cole et al. (2007), Tranvik et al. (2009)

1.4 (40-50%)

0.6 (10-20%)

2.9

PgC/yr

0.9 (30-50%)

Inland waters may play significant role for carbon

15 Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep

LAKE SUPERIOR CARBON BUDGET

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High-fidelity models offer lake-wide perspective

Physical Validation

Velocity and Temperature off the Keweenaw in 1999

Bennington et al. 2010

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Lower food web / biogeochemistry module


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Ecosystem Validation: Nearshore Respiration

HN ONT

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Model indicates a factor of 10 variation in respiration (volumetric)

Modeled mean 1997-2001 = 5.45 TgC/yr

Past estimates used a factor of 2 with respect to observations off the Keweenaw 13-42 TgC/yr.


23 Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Bennington et al. 2012, Urban et al. in prep


R 4.3 – 5.6

7.9-10.1

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Why do Diporeia cluster on the slope?

0

1000

2000

3000

4000

5000

0 50 100 150 200 250 300

Dipo

reia

den

sity (

#/m

2 )

(a)

Auer and Kahn, 2004; Auer et al. in review

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Productivity highest nearshore – as is Respiration

Chlorophyll, after removal of terrestrial dissolved matter signal SeaWiFS satellite August 31, 2006

Mouw et al. in review; in prep

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How much and where does Production and Respiration of labile organic carbon occur? Evaluate with model

• R:P = 1 in nearshore and offshore • Labile organic carbon is largely respired on slope, in a quantity

equivalent to the river subsidy

McKinley and Bennington, in prep

TgC/yr River

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Organic matter from nearshore may provide energy source to help support Diporeia community on slope

Auer and Kahn, 2004; Auer et al. in review

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Sea Lamprey and Climate Change

Kitchell et al. in press, Cline et al., 2013

31 Year

CPU

E (k

g/km

) Te

mpe

ratu

re (°

C)

Wei

ght (

g)

Prey (trout) increasing

Temperature increasing

CPUE = Catch per unit effort

Sea Lamprey weight increasing Second lamprey increase starts mid-1980’s, after prey level off

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Weight vs. Days > 10C (annual data) Days > 10C have

increased from 80’s to 00’s

Sea lamprey weight increase with more days of water at >10C; Model details the warming pattern

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Bioenergetic model of fish and Sea Lamprey

Consumption

C =

Gonads Reproduction

ΔBiomass Growth

+ (ΔB + G)

Respiration Basal Metabolism

Active Metabolism Costs from activity

Specific Dynamic Action Costs from digestion

(R + A + S)

Egestion-F & Excretion -U

+ (F + U)

For Sea Lamprey: Kitchell and Breck (1980) through Madenjian et al. (2008)

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Latit

ude

Longitude

Percent Change in Annual Blood Consumption (g/lamprey)

49°

48°

47°

-91° -92° -90° -88° -89° -86° -87° -85°

Change in blood consumption

between 1979-84 and 2001-2006

Up to 10% increase blood consumption with recent warming

Kitchell et al. in press

35 Year

CPU

E (k

g/km

) Te

mpe

ratu

re (°

C)

Wei

ght (

g)

Prey (trout) increasing

Temperature increasing

CPUE = Catch per unit effort

Sea Lamprey weight increasing Second lamprey increase starts mid-1980’s, after prey level off

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Ocean Acidification: CO2 + H2O = CARBONIC ACID

Carbonic acid lowers pH (increases H+)

With CO2 emissions since 1800, surface ocean pH has declined 0.1 units = 10% increase in H+

Doney et al. 2006

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Model Projection for CaCO3 saturation in 2100

Southern Ocean becomes corrosive to CaCO3 Impacts likely before – some observed already

Orr et al. 2005

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Clearly not good for calcifiers… What about ecosystem effects?

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Will the Great Lakes experience OA?

TWO-BOX MODEL

Simple physics, imposed cycle of productivity,

complete carbon chemistry

Phillips 2012, Phillips et al. in prep

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Will the Great Lakes experience OA? Michigan

Erie Ontario

Huron

Superior

YES

“Business as Usual” scenario (solid) results in pH decline of 0.3 units by 2100, same as surface ocean

BOX MODEL PREDICTION

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Observed trends? Source: EPA bi-annual survey,

average of April and August data, 8-20 sites per lake

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Observed trends? Add box model prediction (black) Source: EPA bi-annual survey,

average of April and August data, 8-20 sites per lake

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Is lake-wide, annual mean pH well-represented by these data?

Observing System Simulation Experiment (OSSE) with

MITgcm.Superior

Model Sampled as data

True annual mean

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Why not? Significant spatio-temporal variability

Modeled: April, August 2000

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Why not? Significant spatio-temporal variability

8.6

8.0

8.2

8.4

Observed pH, June-Sept 2001, every 30 min

6/6/01 7/1/01 8/1/01 9/12/01

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Is Ocean Acidification happening in the Great Lakes?

• Projections with full carbon chemistry indicate OA should occur at same rate as in the ocean in all Great Lakes

• However, the most comprehensive monitoring has not been designed to capture these trends

• High quality, high temporal resolution data, sited to capture lake-wide means, are needed

• Better understanding the mechanisms driving the observed spatio-temporal variability in pH is critical

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Impacts of Ocean Acidification in the Great Lakes? Survey of Experts

Phillips 2012, Phillips et al. in prep

Water Quality

Fish: Early life stages

89 respondents, spring 2012

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Conclusions • Biogeochemistry and physics set the stage for ecosystems

• Predicting responses to changing climate requires better

knowledge of all components

• Well-validated models are an important tool

• Shown here: • Lake Superior’s carbon budget can be balanced once we account for

spatial heterogeneity of respiration • Diporeia in L. Superior may be supported by organic carbon fixed in the

nearshore and advected to the slope • Warming increases Sea Lamprey blood consumption in L. Superior • Ocean Acidification is likely in the Great Lakes, but adequate monitoring

has not yet been implemented

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References 1. Allan, J. D. et al. Joint analysis of stressors and ecosystem services to enhance restoration effectiveness.

(2013).doi:10.1073/pnas.1213841110/ 2. Auer, M. T., Auer, N. A., Urban, N. R. & Auer, T. Distribution of the Amphipod Diporeia in Lake Superior: The Ring of Fire.

SUBMITTED to JGLR 1–45 (2012). 3. Austin, J. A. & Colman, S. M. Lake Superior summer water temperatures are increasing more rapidly than regional air

temperatures: A positive ice-albedo feedback. Geophys Res Lett 34, L06604 (2007). 4. Bennington, V., Mckinley, G. A., Urban, N. R. & McDonald, C. P. Can spatial heterogeneity explain the perceived

imbalance in Lake Superior's carbon budget? A model study. J. Geophys. Res 117, G03020 (2012). 5. Bennington, V., McKinley, G., Kimura, N. & Chin, W. General circulation of Lake Superior: Mean, variability, and trends

from 1979 to 2006. J. Geophys. Res 115, C1201 (2010). 6. Cole, J. J. et al. Plumbing the Global Carbon Cycle: Integrating Inland Waters into the Terrestrial Carbon Budget.

Ecosystems 10, 172–185 (2007). 7. Cotner, J. B., Biddanda, B. A., Makino, W. & Stets, E. Organic carbon biogeochemistry of Lake Superior. Aquatic

Ecosystem Hlth. & Man. 7, 451–464 (2004). 8. Desai, A. R., Austin, J. A., Bennington, V. & McKinley, G. A. Stronger winds over a large lake in response to weakening air-

to-lake temperature gradient. Nature Geoscience 2, 855–858 (2009). 9. Doney, S. C. The dangers of ocean acidification. Sci. Am. 294, 58–65 (2006). 10. Kitchell, J.F., T. Cline, V. Bennington and G.A. McKinley (2012) Challenges of managing invasive sea lamprey in Lake

Superior. In Bioeconomics of Invasive Species: Integrating Ecology, Economics, Policy and Management. ed: R. P. Keller, D. M. Lodge, M. A. Lewis, J. F. Shogren, University of Chicago Press, in press.

11. McKinley, G. A., Urban, N., Bennington, V., Pilcher, D. & McDonald, C. Preliminary Carbon Budgets for the Laurentian Great Lakes. OCB News 4, (2011).

12. Orr, J. C. et al. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437, 681–686 (2005).

13. Phillips, J. G.A. McKinley, H. Bootsma, R.W. Sterner, N. Urban and V. Bennington. Evaluating the prospects for Great Lakes Ocean Acidification

14. Phillips, J.C. Learning from the global oceans: The potential for and ecological impacts of CO2-driven acidificaiton of the Great Lakes. MS Thesis, University of Wisconsin – Madison. 2012

15. Sarmiento, J.L. and N. Gruber. 2006. Ocean Biogeochemical Cycles. Princeton University Press. 16. Talley et al. 2011. Descriptive Physical Oceanography, Elesvier 17. Tranvik, L. J. et al. Lakes and reservoirs as regulators of carbon cycling and climate. Limnol Oceanogr 54, 2298–2314

(2009). 18. Urban, N. et al. Carbon cycling in Lake Superior. J. Geophys. Res 110, C06S90 (2005).

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Climate and carbon impacts on productivity, chemistry and...

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