climate and carbon impacts on productivity, chemistry and...
TRANSCRIPT
1
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
2
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
3
Biogeochemistry is elemental cycling and flux between reservoirs, and interactions with lower food web
Sarmiento and Gruber, 2006, fig 4.4.1
4
Physics sets the stage
Talley et al., 2011, fig 9.1; NASA image
Satellite Chlorophyll
5
Physics sets the stage
Movie of modeled tracer advection in Lake
Superior shown here (MITgcm.Superior)
6
Together, physics and biogeochemistry are the infrastructure on which ecosystems depend
7
New York Times, 8 Jan 2013
Climate change has arrived
8
The Great Lakes are feeling the heat
Desai et al. 2009, Austin and Colman 2007
9
Impacts of climate change and other stressors on ecosystems? Non-linear effects? Need to understand physics, biogeochemistry.
Allan et al., 2013
10
Further, warming is due to anthropogenic CO2
11
What is the Great Lakes role in the carbon cycle?
IPCC AR4, 2007, Figure 7.3
12
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
13
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
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
16
High-fidelity models offer lake-wide perspective
Physical Validation
Velocity and Temperature off the Keweenaw in 1999
Bennington et al. 2010
18
Lower food web / biogeochemistry module
Bennington et al. 2012
19
Ecosystem Validation: Nearshore Respiration
HN ONT
20 Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep
LAKE SUPERIOR CARBON BUDGET
21
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.
Bennington et al. 2012
22 Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep
LAKE SUPERIOR CARBON BUDGET
23 Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Bennington et al. 2012, Urban et al. in prep
LAKE SUPERIOR CARBON BUDGET
R 4.3 – 5.6
7.9-10.1
24
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
25
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
26
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
27
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
28
Organic matter from nearshore may provide energy source to help support Diporeia community on slope
Auer and Kahn, 2004; Auer et al. in review
29
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
30
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
32
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
33
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)
34
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
36
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
37
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
38
Model Projection for CaCO3 saturation in 2100
Southern Ocean becomes corrosive to CaCO3 Impacts likely before – some observed already
Orr et al. 2005
39
Clearly not good for calcifiers… What about ecosystem effects?
40
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
41
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
42
Observed trends? Source: EPA bi-annual survey,
average of April and August data, 8-20 sites per lake
43
Observed trends? Add box model prediction (black) Source: EPA bi-annual survey,
average of April and August data, 8-20 sites per lake
44
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
45
Why not? Significant spatio-temporal variability
Modeled: April, August 2000
46
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
47
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
48
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
49
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
50
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).
51
Questions?