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Echoes in the Ecosystem

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An overview of a collaborative project between the Lake Ecosystem Group at the Centre for Ecology & Hydrology, Lancaster, and the Grey Lab at Queen Mary University of London.
The project is funded by the Natural Environment Research Council Ecology & Hydrology Funding Initiative, and includes project partners at the Freshwater Biological Association and Queen's University Belfast.

Published in: Technology
  • Hi Andrew,
    Thanks for the interest in the work. Please just reference it as Maberly et al (2012) Echoes in the Ecosystem and maybe give the URL of the project webpages: http://www.windermere-science.org.uk/home
    What are you using it for if you don't mind me asking?
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  • Hi, with your permission I would like to powerphrase a paragraph on slide 15. How would you like me to reference your work?
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Echoes in the Ecosystem

  1. 1. Echoes in the ecosystem: top-down & bottom-up responses of Windermere to environmental perturbation Stephen Maberly, Ian Jones, Stephen Thackeray, Ian Winfield & Peter Henrys Lake Ecosystem Group Centre for Ecology & Hydrology, Lancaster UKNERC project in association with:Jonathan Grey & Peter Smyntek- Queen Mary University of LondonProject partners:Mike Dobson- FBAChris Harrod- Queen’s University Belfast
  2. 2. Windermere • England’s largest lake • Two basins: deeper, less productive North and shallower more productive South • One of the most intensively studied lakes in the world • Long-term data and archives from early 1900s and regular sampling for range of variables since 1945 • Freshwater Biology Special Issue planned for Jan or Feb 2012Photos fromFBA ImageArchive
  3. 3. Multiple stressors Natural variability in weather Schematic of changes in multiple stressors in Windermere Acidification Nutrient enrichment Climate change Invasion of non-native species Tertiary Detectable Climate change Sew age w orks installed Sulfate loading treatment change in w ater Acid declines temperature(& nutrients) Large No.s of 1 roach detected Nutrients (& toxins) 0.8 0.6 Stress 0.4 0.2 0 1940 1950 1960 1970 1980 1990 2000 2010 Year
  4. 4. Publications on invasive species & freshwater Search on Web of Science, May 2011
  5. 5. Response to changing P40 Mean winter TP (mg m-3) Mean Chla (mg m ) -335 1230 1025 820 61510 4 North Basin 5 2 North Basin South Basin 0 South Basin 0 1950 1960 1970 1980 1990 2000 2010 1950 1960 1970 1980 1990 2000 2010 Year Year 10 -3 Min O2 at depth (g m-3) Mean winter SRP (mg m )30 Max pH 10 825 North Basin South Basin20 6 915 410 8 2 North Basin North Basin5 South Basin South Basin 7 00 1950 1960 1970 1980 1990 2000 2010 1950 1960 1970 1980 1990 2000 20101950 1960 1970 1980 1990 2000 2010 Year Year Year
  6. 6. Seasonal patterns of phytoplankton change Spring Summer 20 North Basin South Basin 20 16 16Chla in M,A,M (mg m-3) Chla in J,J,A (mg m-3) 12 12 8 8 4 4 0 0 1960 1970 1980 1990 2000 2010 1960 1970 1980 1990 2000 2010 Year Year Lines are 3-year moving averages
  7. 7. Zooplankton 40 North Basin18 -3 Mean zooplankton (No. dm ) 1977-199116 Mean Zooplankton (No. dm ) 1993-2007 -314 3012108 2064 North Basin2 South Basin 1001950 1970 1990 2010 0 0 3 6 9 12 Month
  8. 8. Fish predation? 6000 CPUE (fish (Fish 100 m net-1day ) -1) 50 CPUE 100 m net-1 day -1Abundance (fish ha )-1) 5000 40 Abundance (fish ha -1 4000 30 2 2 3000 20 2000 10 1000 0 1995 2000 2005 2010 Year 0 1990 1995 2000 2005 2010 Year Largely roach
  9. 9. Climate change and roach invasion? Maitland 1972 Roach distribution Mean surface temperature (oC)1210 Davies et al. 20048 North Basin South Basin6 ‘It is not unlikely that these had been brought as live- 1950 1970 1990 2010 bait for pike, as live-baiting Year is occasionally done by strangers.’ (Watson, 1925)
  10. 10. Possible consequences for Arctic charrCatch per unit effort on spawning grounds 100 100 20 North Basin North Basin Catch per unit effort on spawning grounds 90 90 18 Summer zooplankton (No. dm-3) 80 80 16 70 70 14 60 60 12 50 50 10 40 40 8 30 30 6 20 20 4 Arctic charr 10 Arctic charr 10 2 Summer zooplankton 0 0 0 1950 1960 1970 1980 1990 2000 2010 1950 1960 1970 1980 1990 2000 2010 Year Year
  11. 11. • Echoes in the ecosystemCarnivores Changes in Pike dietPlanktivores Increase in Reduction in roach Arctic charrZooplankton Reduction in zooplankton Increase inPhytoplankton phytoplankton Chemistry Increased Reduction internal P- in oxygen at Climate load depth change Warmer Stronger water stratification Physics
  12. 12. Mixed layer depth & light availability Day of year 0 50 70 90 110 130 150 -5 -10 -15 seventiesDepth (m) -20 eighties -25 nineties naughties -30 -35 -40 seventies naughties -45 South Basin
  13. 13. Phytoplankton edibility changes? 1000000000 1000000000 Biolvol in JJA of algae < or >50 µm (µm3 cm-3) >50 umAverage biovolume in JJA (µm3 cm-3) 100000000 100000000 y = 1E+07e-0.152x P<0.05 <50 um R² = 0.155 10000000 10000000 1000000 1000000 100000 100000 10000 y = 306565e-0.065x R² = 0.174 P<0.05 1000 10000 1950 1970 1990 2010 0 5 10 15 20 Year Zooplankton density in JJA (No. dm-3) North Basin
  14. 14. Path-analysis for the North Basin (Bayesian belief network implemented in Winbugs) Roach Arctic charr numbers numbers 4% Zooplankton density in summer 12% Phytoplankton (Chla) in summer Oxygen concentration Water at depthtemperature 6% 30%
  15. 15. Conclusions• Multiple stressors have affected Windermere over the last 65 years via top-down and bottom-up processes- the response of a complicated ecosystem to perturbation is complex• Nutrient enrichment has had the major impact but more recently climate change interacting with expansion of a non-native species has started to alter the food-web and the way the lakes converts resources into algae• Climate change is likely to make the achievement of water quality and conservation objectives more difficult and nutrient targets will have to be more stringent
  16. 16. Acknowledgements• We thank the FBA (1945 to 1989) and our colleagues in CEH/IFE (1989-present) for (1989- collecting the long-term data analysed here long-• This work was funded by a NERC EHFI grant to CEH and QMUL• See our web-page: http://www.windermere- web- http://www.windermere- science.org.uk/home

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