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Climate Change and Freshwater
Biology 402 Lecture October 1, 2009
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Outline Current and Projected Climate Change Case Studies
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES CASE STUDY LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Outline Current and Projected Climate Change Case Studies Climate Change Impacts Lakes in Canada’s Boreal Forest Climate Change Reduces Productivity in Lake Tanganyika, Africa Ways of Forecasting the Effects of Future Climate Change
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IPCC 2001 CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES
LAKE TANGANYIKA FORECASTING FUTURE IMPACTS IPCC 2001
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IPCC 2007 CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES
LAKE TANGANYIKA FORECASTING FUTURE IMPACTS IPCC 2007
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Surface waters of northern hemisphere lakes expected to increase 1-7°C by 2100 Magnuson et al. 1997
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IPCC 2007 CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES
LAKE TANGANYIKA FORECASTING FUTURE IMPACTS IPCC 2007
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Changes in Precipitation
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Changes in Precipitation IPCC 2007
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Changes in Glacier Mass
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Changes in Glacier Mass IPCC 2007
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Alberta Glaciers Reduced By ~25% in Last Century
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Alberta Glaciers Reduced By ~25% in Last Century 1897 2002 Schindler and Donahue, 2006
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Climate Warming Is Extending Ice Free Season
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Climate Warming Is Extending Ice Free Season Jensen et al. 2007
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Invasive Species Rahel and Olden, 2008 CLIMATE - CURRENT AND PROJECTED
CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Invasive Species Rahel and Olden, 2008
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Effects of Climatic Warming on Lakes of the Central Boreal Forest Science D.W. Schindler, K.G. Beaty, E.J. Fee, D.R. Cruikshank, E.R. DeBruyn, D.L. Findlay, G.A. Linsey, J.A. Shearer, M.P. Stainton, and M.A. Turner
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Long Term Data Set (1969-1990) ELA - Experimental Lakes Area
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Long Term Data Set ( ) ELA - Experimental Lakes Area Climate Data Hydrological Data Lake Chemistry Data Biological Data Schindler et al. 1990
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Increased by ~2°C Schindler et al. 1990 CLIMATE - CURRENT
AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Increased by ~2°C Schindler et al. 1990
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Warmer Lake Temp Longer Ice Free Season Increased by ~2°C
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Warmer Lake Temp Longer Ice Free Season Increased by ~2°C Schindler et al. 1990
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Reduced run-off and water renewal rates Schindler et al. 1990
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Increased by ~2°C Reduced run-off and water renewal rates Reduction in average precipitation Schindler et al. 1990
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Leads to overall increase in N:P ratio, increasing P limitation
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Increased Nitrogen Reduced run-off and water renewal rates Leads to overall increase in N:P ratio, increasing P limitation
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Increased Phytoplankton
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Increased Nutrients Increased Phytoplankton Biomass and Diversity Warmer Water Schindler et al. 1990
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Forest Fires in 1974 and 1980 Burned Large Parts of Watershed
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Forest Fires in 1974 and 1980 Burned Large Parts of Watershed
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Warmer Temperatures and Reduced Forest Cover Caused Higher
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Warmer Temperatures and Reduced Forest Cover Caused Higher Wind Velocities Schindler et al. 1990
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Increase in Water Clarity
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Reduced Runoff and Organic Matter in Watershed Caused an Increase in Water Clarity Schindler et al. 1990
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Increased Light Penetration and Wind Velocity Caused
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Increased Light Penetration and Wind Velocity Caused Thermocline to Deepen Schindler et al. 1990
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Deepening of Thermocline May Extirpate Species That
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Deepening of Thermocline May Extirpate Species That Rely on Cold Oxygenated Water in The Hypolimnion as a Refuge nas.er.usgs.gov Schindler et al. 1990
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Summary Longer Warmer Summers More Nutrients and Phytoplankton
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Summary Longer Warmer Summers More Nutrients and Phytoplankton Deeper Thermoclines Possible Extirpation of Cold Water Species Schindler et al. 1990
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Climate Change Decreases Aquatic Ecosystem Productivity of Lake Tanganyika, Africa Nature C.M. O’Reilly, S.R. Alin, P-D. Plisnier, A.S. Cohen, and B.A. McKee
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Lake Tanganyika Extremely large
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Lake Tanganyika Extremely large Average Depth - 570m Max Depth - 1,470m Mean Width - 50km Mean Length - 650km Surrounded by Burundi, Tanzania, Zambia, and the Democratic Republic of Congo O’Reilly et al. 2003
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Importance of Lake Historically supported highly productive fishery
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Importance of Lake Historically supported highly productive fishery 165, ,000 metric tons per year Large source of nutrition and revenue for neighboring countries travel.aol.com However, fishery productivity has been declining O’Reilly et al. 2003
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Climate Changes Warmer air temperatures Lower wind velocities
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Climate Changes Warmer air temperatures Lower wind velocities O’Reilly et al. 2003
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More Stable Surface Waters
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS More Stable Surface Waters 150 m Warmer waters at all depths Reduced mixing Decreasing upwelling of nutrient rich deep waters 600 m Depth of Stratification O’Reilly et al. 2003
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Warmer Waters and Shallower
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Warmer Waters and Shallower Overall reduction in primary productivity (~20%) Explains the decrease in fish productivity O’Reilly et al. 2003
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Summary Climate change increased surface water stability - warming and less wind Reductions in deepwater nutrient upwelling Lower primary productivity resulted in declines in fish productivity Future projections of °C air temp warming in next 80 years Further reductions in ecosystem productivity O’Reilly et al. 2003
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Forecasting Future Impacts of Climate Change
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Forecasting Future Impacts of Climate Change
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Long Term Data Sets Look at past changes in climate and extrapolate using future climate scenarios
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS However . . . The way ecosystems respond may not be constant across further increases in temperature
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Arctic Daphnia show non-linear feeding response with increasing temperature If curve different from prey growth rates, trophic interactions will change with temperature Yurista 1999
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Requires investigation into the mechanisms behind biotic interactions
CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Requires investigation into the mechanisms behind biotic interactions
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CLIMATE - CURRENT AND PROJECTED CASE STUDY CANADA’S LAKES LAKE TANGANYIKA FORECASTING FUTURE IMPACTS Long term data sets coupled with mechanistic experiments provide good way of predicting future climate change effects on aquatic ecosystems
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