1. Surface waters under multiple stress Peeter Nõges Centre for Limnology, Estonian University of Life Sciences

2. Outline Global change & water resources Dominant stressor combinations Stressor interactions EU project MARS

4. Global distribution of evaporation and precipitation

5. Redistribution of air moisture 19 May 2016Baltic Water Works Conference Dry becomes dryer and wet becomes wetter

6. 19 May 2016Baltic Water Works Conference Rising sea surface temperature Lehmann et al., 2011 Jurgensone et al., 2011 1990–2008 1976–2008 Average trend 1 ºC/decade

7. 19 May 2016Baltic Water Works Conference Suursaar, 2011Jaagus & Kull, 2011 Strengthening westerlies

8. 19 May 2016Baltic Water Works Conference Projected changes in river flow Higher winter runoff Earlier flood peak Slightly higher summer minimum Higher autumn runoff

9. 19 May 2016Baltic Water Works Conference Main pressures Diffuse pollution Point-source pollution Toxic pollution Hydromorphological modification Damming Water abstraction Alien species Overfishing Thermal pollution

10. The MARS review 19 May 2016Baltic Water Works Conference Nõges et al. 2016

11. Stressor combinations Nõges et al. 2016

12. Types of stressor interaction Additive Synergistic Antagonistic 2+2 = 4 2+2 = 3 2+2 = 5

13. Pressures on surface waters in Estonia Source: Ministry of the Environment

14. Point source loading in Estonia 1994-2012 Source: Ministry of the Environment

15. Mean pollutant concentrations in Estonian rivers in 1992-2012 Source: Ministry of the Environment

16. Mean total nitrogen concentration in Estonian rivers vs amount of precipitation in 1992-2012 Source: Ministry of the Environment

17. 19 May 2016 Baltic Water Works Conference Temperature & nitrogen affect cyanobacteria In warmer climate, elevated nitrogen concentrations will have a stronger stimulating effect on cyanobacteria. Jeppesen et al. 2011 Kosten et al. 2012

18. 19 May 2016Baltic Water Works Conference Global warming reinforces eutrophication Moss et al. 2012

19. 19 May 2016 Fish-kills in Lake Peipsi-Pihkva A. Kangur et al., 2007 Baltic Water Works Conference

20. Dams on Estonian rivers 19 May 2016Baltic Water Works Conference 966 man-made dams on Estonian rivers. About 300 of them hinder fish passage. 17 dams have a fish ladder (1,8%) www.kik.ee

21. Hydropower stations in Estonia 19 May 2016 Baltic Water Works Conference www.energiatalgud.ee

22. Mesocosm experiments Case study catchments Scenario modelling 2014-2017 Diagnostic tools 19 May 2016 Baltic Water Works Conference

23. What will MARS do 19 May 2016Baltic Water Works Conference WFD assessment ? Bayesian Belief Networks

24. Thank you!