ICP waters; use of data from EMEP …and some results Brit Lisa Skjelkvåle and Heleen de Wit Norwegian Institute for Water Research

ICP Waters: International cooperative programme on assessment and monitoring effects of air pollution on rivers and lakes Programme aims Assess the degree and geographic extent of the impact of atmospheric pollution, in particular acidification, on surface waters Collect information to evaluate dose/response relationships Describe and evaluate long-term trends and variation in aquatic chemistry and biota attributable to atmospheric pollution

Surface water ecosystems

The recovery process Damage Recovery (conceptual model by Posch et al.) Simplified description of development of acid deposition, a lake chemical variable (ANC) the corresponding biological response Damage Recovery

Lake Saudlandsvatn in Southern Norway

Observations L.Saudlandsv Reference. Hestagen et al 2011, Sci Tot Environ

Ex-post deposition scenarios for L Ex-post deposition scenarios for L.Saudlandsvatn Reference:WGE Joint report

Ex-post water chemistry scenarios for L Ex-post water chemistry scenarios for L.Saudlandsvatn NAT – scenario MAGIC Reference: WGE Joint report

Exceedance of CL for acidification of surface waters in Norway using NAT, PRI and MFR scenarios The calculated exceedance of critical loads for acidification of surface waters, using the FAB model (Reference: Letter to KLIF, T. Larssen Dec 2010)

ICP Waters network Chemistry at all sites Biology at selected sites and not in all countries

Trends in ANC 1990-1999 and 1999-2008 ICP Waters sites All median trend slopes in all regions are positiv Slightly lower increase 1999-2008 than 1990-1999

Some reflections The aim of the effects work is to: document the effects of decreases or increases in air pollution by monitoring sensitive parts of natural and seminatural ecosytems, health and materials document need for further emission reductions From ICP Waters reporting: The consistent pattern of chemical recovery across a large number of sites is the strongest evidence that emission control programmes are effective. In many areas, water quality is now sufficient for the return of acid-sensitive aquatic biota.

..and some more reflections ICP Waters needs: Measured precipitation chemistry for relating observed trends in water chemistry with observed precipitation chemistry Historical S and N (and base cation) deposition for calibrating dynamic models Future S and N deposition scenarios for calculating possible water chemical responses possible biological responses exceedance of CL Better cooperation EMEP - WGE; define joint projects and publish results together

Thank you!