1. WGE 29th session, September 2010 1Brit Lisa Skjelkvåle ITEM 4 Common Workplan items ICP Waters ECE/EB.AIR/WG.1/2010/6

2. WGE 29th session, September 2010 2Brit Lisa Skjelkvåle 1. Targets and ex-post application MAGIC modeling of calibrated sites in Norway and Czech rep, possible also some other countries Relate results to possibilities for biological recovery (increase in ANC) Use long-term monitoring data on water chemistry and biota when possible Present results for discussions at JEG- meeting in late October

3. WGE 29th session, September 2010 3Brit Lisa Skjelkvåle 2. Robustness There is generally good agreement between exceedence of critical load for acidity and the acid neutralizing capacity (ANC) in surface waters. Exceptions are sites with time delays between changes in S+N deposition and response in water chemistry. Time delays are well explained by known processes in catchments and waters, and can be modelled

4. WGE 29th session, September 2010 4Brit Lisa Skjelkvåle 2. Robustness There is also good agreement between chemical criteria (ANC) and biological response

5. WGE 29th session, September 2010 5Brit Lisa Skjelkvåle 3. Links with biodiversity The major effect from S- and N-deposition on aquatic ecosystems is the loss of biodiversity. 10 000 stocks of brown trout, roach, Arctic char, and perch, have recently disappeared from Fennoscandian lakes (Tammi, 2003). A major part of the invertebrate fauna is also lost in acidifiedlakes and rivers due to acidification. Recovery of the biodiversity has begun in many regions, but lags behind chemical recovery.

6. WGE 29th session, September 2010 6Brit Lisa Skjelkvåle 3. Links to biodiversity; Areas with lost or damaged fish populations due to acid rain

7. WGE 29th session, September 2010 7Brit Lisa Skjelkvåle Deposition  water chemistry  biota (fish and inverterates) 3. Links to biodiversity; recovery of fish and ivertebrates due to redusced S-deposition

8. WGE 29th session, September 2010 8Brit Lisa Skjelkvåle 4. Trends in selected monitored/modeled parameters

9. WGE 29th session, September 2010 9Brit Lisa Skjelkvåle 4. Trends in selected monitored/modelled parameters Trends in sulphate; 1990-1999, 2000-2009 Still decreasing sulphate trends in most regions, but trends are slower rate

10. WGE 29th session, September 2010 10Brit Lisa Skjelkvåle 4. Trends in selected monitored/modelled parameters Trends in ANC; 1990-1999, 1999-2008 Still increasing trends in ANC but at a lower rate than in the 90’ies

11. WGE 29th session, September 2010 11Brit Lisa Skjelkvåle 4. Trends in selected monitored/modelled parameters - trends in biota (invertebrates) Increasing trends, but at a lower rate in recent years compared to the 90’ies