1. BSU, Minsk

2. The Naroch Lakes consist of three connected lakes: Batorino, Miastro, and Naroch in Northwest Belarus LakesNarochMiastroBatorinoShvakshti Chl, mkg/l0.953.458.4041.89

3. Naroch lakes Нарочь Мястро Баторино

4. General characteristics of the Naroch lakes Indices Lakes NarochMiastroBatorino Watershed area, km 2 279,0133,092,3 Lake area, km 2 79,613,106,3 Specific watershed 3,510,214,6 Depth (average), m 9,05,43,0 Depth (maximum), m 24,811,35,5 Water exchange time, yr 11,02,51,0

5. Dynamics of total phosphorus in the lakes of Naroch group.

6. Dynamics of chlorophyll concentration in the lakes of the Naroch group

7. Dynamics of zooplankton biomass in the lakes of the Naroch group

8. Dynamics of the Secchi depth in the lakes of the Naroch group.

9. The cause of changes observed in Naroch lakes Management of external nutrient flows (decrease of external nutrient loading) Appearance in lakes powerful filtrator - Dreissena polymorpha Decrease of intensity of economic activity

10. Dynamics of the ratio of trophogenic/total lake volume in the Naroch lakes

11. Dynamics of the ratio of trophogenic/total bottom area in the Naroch lakes

12. L. Naroch Standing crop of macrophytes

13. L.Naroch Total GPP (plankton + macrophytes + mikrophytobenthos + epiphyton) in different periods

14. L. Naroch Biomass of zoobenthos before and after Dreissena polimorpha invade

16. Benthification “We define benthification as an increase in the importance of benthic processes following increased water clarity promoted by nutrient reduction and Dreissena introduction” Christine Mayer Lake Erie Center of the University of Toledo

17. Dynamics of GPP/R ratio in Naroch Lakes

18. Multiannual dynamics of GPP/R ratio, chlorophyll concentration, total nitrogen and phosphorus in the water samples of lake Miastro (values normalized to 1978)

19. Multiannual dynamics of GPP/R ratio, chlorophyll concentration, total nitrogen and phosphorus in the water samples of lake Batorino (values normalized to 1978)

20. Multiannual dynamics of GPP/R ratio, chlorophyll concentration, total nitrogen and phosphorus in the water samples of lake Naroch (values normalized to 1978)

21. Dynamics of GPP/R ratio (%) in Naroch Lakes and the “forecast” this ratio for L. Naroch

22. Correlation between GPP/R ratio and water level in lakes Naroch and Mjastro

23. Partition of the assimmilation fluxes in L. Naroch (gС/m 2 veg. season) over the periods of 1980-1985 and 2004-2009 CommunityPeriod Ratio 2/1 1980–1985 (1) 2004-2009 (2) Phytoplankton73112 1,5 Makrophytes15775,1 Periphyton57460,8 Σ autotrophic1452351,6 Bacterioplankton1201050,9 Zooplankton13211,6 Zoobenthos35217,3 Σ heterotrophic 1351771,3

24. Naroch biological station in the past and in the present

25. Naroch biological station

28. Thank you for your attention!