Climate and carbon impacts on productivity, chemistry and invasive species in the Great Lakes

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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

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 2

3 Biogeochemistry is elemental cycling and flux between reservoirs, and interactions with lower food web Sarmiento and Gruber, 2006, fig

4 Physics sets the stage Satellite Chlorophyll Talley et al., 2011, fig 9.1; NASA image 4

5 Physics sets the stage Movie of modeled tracer advection in Lake Superior shown here (MITgcm.Superior) 5

6 Together, physics and biogeochemistry are the infrastructure on which ecosystems depend 6

7 Climate change has arrived New York Times, 8 Jan

8 The Great Lakes are feeling the heat Desai et al. 2009, Austin and Colman

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

10 Further, warming is due to anthropogenic CO 2 10

11 What is the Great Lakes role in the carbon cycle? IPCC AR4, 2007, Figure

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 12

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 13

14 Inland waters may play significant role for carbon PgC/yr 1.4 (40-50%) (30-50%) 0.6 (10-20%) Cole et al. (2007), Tranvik et al. (2009) 14

15 LAKE SUPERIOR CARBON BUDGET Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep 15

16 High-fidelity models offer lake-wide perspective 16

17 Physical Validation Velocity and Temperature off the Keweenaw in 1999 Bennington et al. 2010

18 Lower food web / biogeochemistry module Bennington et al

19 Ecosystem Validation: Nearshore Respiration H ONT N 19

20 LAKE SUPERIOR CARBON BUDGET Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep 20

21 Model indicates a factor of 10 variation in respiration (volumetric) Past estimates used a factor of 2 with respect to observations off the Keweenaw TgC/yr. Modeled mean = 5.45 TgC/yr Bennington et al

22 LAKE SUPERIOR CARBON BUDGET Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Urban et al. in prep 22

23 LAKE SUPERIOR CARBON BUDGET R Cotner et al, 2004; Urban et al., 2005; Sterner 2010; Bennington et al. 2012, Urban et al. in prep 23

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 24

25 Why do Diporeia cluster on the slope? Diporeia density (#/m 2 ) (a) Auer and Kahn, 2004; Auer et al. in review 25

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 26

27 How much and where does Production and Respiration of labile organic carbon occur? Evaluate with model River TgC/yr 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 27

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 28

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 29

30 Sea Lamprey and Climate Change Kitchell et al. in press, Cline et al.,

31 CPUE (kg/km) Temperature ( C) Weight (g) Prey (trout) increasing Temperature increasing Sea Lamprey weight increasing CPUE = Catch per unit effort Second lamprey increase starts mid-1980 s, after prey level off Year 31

32 Sea lamprey weight increase with more days of water at >10C; Model details the warming pattern Weight vs. Days > 10C (annual data) Days > 10C have increased from 80 s to 00 s 32

33 Bioenergetic model of fish and Sea Lamprey Active Metabolism Costs from activity Consumption Respiration Basal Metabolism Specific Dynamic Action Costs from digestion Gonads Reproduction ΔBiomass Growth Egestion-F & Excretion -U C = (R + A + S) + (F + U) + (ΔB + G) For Sea Lamprey: Kitchell and Breck (1980) through Madenjian et al. (2008) 33

34 Up to 10% increase blood consumption with recent warming Latitude Change in blood consumption between and Longitude Percent Change in Annual Blood Consumption (g/lamprey) Kitchell et al. in press 34

35 CPUE (kg/km) Temperature ( C) Weight (g) Prey (trout) increasing Temperature increasing Sea Lamprey weight increasing CPUE = Catch per unit effort Second lamprey increase starts mid-1980 s, after prey level off Year 35

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 36

37 Ocean Acidification: CO 2 + H 2 O = CARBONIC ACID Doney et al Carbonic acid lowers ph (increases H + ) With CO 2 emissions since 1800, surface ocean ph has declined 0.1 units = 10% increase in H + 37

38 Model Projection for CaCO 3 saturation in 2100 Southern Ocean becomes corrosive to CaCO 3 Impacts likely before some observed already Orr et al

39 Clearly not good for calcifiers What about ecosystem effects? 39

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 40

41 Will the Great Lakes experience OA? Michigan BOX MODEL PREDICTION Erie Ontario Huron Superior YES Business as Usual scenario (solid) results in ph decline of 0.3 units by 2100, same as surface ocean 41

42 Observed trends? Source: EPA bi-annual survey, average of April and August data, 8-20 sites per lake 42

43 Observed trends? Source: EPA bi-annual survey, average of April and August data, 8-20 sites per lake Add box model prediction (black) 43

44 Is lake-wide, annual mean ph well-represented by these data? Model Sampled as data Observing System Simulation Experiment (OSSE) with MITgcm.Superior True annual mean 44

45 Why not? Significant spatio-temporal variability Modeled: April, August

46 Why not? Significant spatio-temporal variability Observed ph, June-Sept 2001, every 30 min /6/01 7/1/01 8/1/01 9/12/01 46

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 47

48 Impacts of Ocean Acidification in the Great Lakes? Survey of Experts Water Quality Fish: Early life stages Phillips 2012, Phillips et al. in prep 89 respondents, spring

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 49

50 References 1. Allan, J. D. et al. Joint analysis of stressors and ecosystem services to enhance restoration effectiveness. (2013).doi: /pnas / 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 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, (2007). 7. Cotner, J. B., Biddanda, B. A., Makino, W. & Stets, E. Organic carbon biogeochemistry of Lake Superior. Aquatic Ecosystem Hlth. & Man. 7, (2004). 8. Desai, A. R., Austin, J. A., Bennington, V. & McKinley, G. A. Stronger winds over a large lake in response to weakening airto-lake temperature gradient. Nature Geoscience 2, (2009). 9. Doney, S. C. The dangers of ocean acidification. Sci. Am. 294, (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, (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 Sarmiento, J.L. and N. Gruber Ocean Biogeochemical Cycles. Princeton University Press. 16. Talley et al Descriptive Physical Oceanography, Elesvier 17. Tranvik, L. J. et al. Lakes and reservoirs as regulators of carbon cycling and climate. Limnol Oceanogr 54, (2009). 18. Urban, N. et al. Carbon cycling in Lake Superior. J. Geophys. Res 110, C06S90 (2005). 50

51 Questions? 51