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WGE 27.-29. September 2011 1Brit Lisa Skjelkvåle
Trends in precipitation chemistry, surface water chemistry and aquatic
biota in acidified areas in Europe and North America from 1990 to
2008
ICP Waters Programme CentreNorwegian Institute for Water Research
WGE 27.-29. September 2011 2Brit Lisa Skjelkvåle
Aim of the report
• Describe the changes in acid sensitive aquatic ecosystems in Europe and North America due to emission reductions
WGE 27.-29. September 2011 3Brit Lisa Skjelkvåle
The last 50 years
• 60s – 70s: increase in deposition - severe acidification – fish deaths – forest dieback – concerns leading to establishment of the LRTAP Convention
• 80s : decrease in deposition - small (no) changes in water chemistry and no changes in biota
• 90s : large decrease in deposition - large changes in water chemistry and small positive changes (recovery) in biota
• 00s : ??
– Does the positive development in water chemistry continue? and at what rate?
– What is the rate of change in the biological recovery?
WGE 27.-29. September 2011 4Brit Lisa Skjelkvåle
Chain of effects
Emission reductions of S and N
changes in precipitation chemistry
changes in water chemistry
possible effects on aquatic biota (recovery)
WGE 27.-29. September 2011 5Brit Lisa Skjelkvåle
Responsible for the different parts of the report
• Emissions: From EMEP reports
• Precipitation: EMEP CCC contribution
• Water chemistry: ICP Waters database and all Task Force members
• Biology: National contributions from 6 countries
WGE 27.-29. September 2011 6Brit Lisa Skjelkvåle
Time spans in the report
1990 – 1999 = 90s1999 – 2008 = 00s
and the whole period together1990 - 2008
WGE 27.-29. September 2011 7Brit Lisa Skjelkvåle
Emissions reductions US Canada Europe
1990-2008 50% 46% 61% 1990-19991) 24% 28% 50% 1999-20081) 35% 25% 24%
-75%
-50%
-25%
0%
25%
50%
75%
100%
1990-2008 1990-1999 1999-2008 1990-2008 1990-1999 1999-2008
Sites with decreasing trend Average change in concentration
Europe (EMEP) US(NADP+ CAPMoN)
Changes in concentrations in precipitation
S
WGE 27.-29. September 2011 8Brit Lisa Skjelkvåle
Emissions reductions US Canada Europe
1990-2008 36% 14% 25% 1990-19991) 11% -3% 24% 1999-20081) 28% 13% 2%
-50%
-25%
0%
25%
50%
75%
100%
1990-2008 1990-1999 1999-2008 1990-2008 1990-1999 1999-2008
Sites with decreasing trend Average change in concentration
Europe (EMEP) US(NADP+ CAPMoN)
NOx
Changes in concentrations in precipitation
WGE 27.-29. September 2011 9Brit Lisa Skjelkvåle
EMEP CCC monitoring network used for the analysis
WGE 27.-29. September 2011 10Brit Lisa Skjelkvåle
ICP Waters network
Chemistry at all sitesBiology at selected sites and not in all countries
WGE 27.-29. September 2011 11Brit Lisa Skjelkvåle
Changes in sulphate* concentrations in surface waters
Region % 90-08 % 90-99 % 99-08 NoNordic -39 -21 -18 SoNordic -58 -37 -21 UKIreland -48 -33 -15 WCEurope -30 -18 -11 ECEurope -34 -35 1 Alps -25 -18 -7 Maine_Atlantic -38 -16 -22 Vermont_Quebec -39 -25 -14 Adirondacks -33 -16 -17 Appalachians -20 -13 -7 Blue Ridge Mountains -1 0 -1 Ontario -33 -27 -6
÷÷
÷
÷
÷
÷
÷
÷
+
+
+
÷
WGE 27.-29. September 2011 12Brit Lisa Skjelkvåle
Trends in ANC 1990-1999 and 1999-2008 ICP Waters sites
All median trend slopes in all regions are positivSlightly lower increase 1999-2008 than 1990-1999
WGE 27.-29. September 2011 13Brit Lisa Skjelkvåle
Main conclusions of changes in water chemistry
Sulphate:
About 70 % of nearly 200 sites, and 11 of 12 regions show significant declines in non-marine sulphate in the 90s and the 00s.
Decrease has slowed down in the 00 compared to the 90s
Nitrogen:
Most sites show no significant trends in nitrate
The relative importance of NO3 for acidification of surface waters has increased
The changes in N is the same for the 90s and the 00s
WGE 27.-29. September 2011 14Brit Lisa Skjelkvåle
Main conclusions of changes in water chemistry
Alkalinity/ANC:
Increase has slowed down in most regions
pH:
Most European regions show more improvements in the 00s while in North America the changes it is much of the same
Organic carbon:
No evident differences between the two periods – still increase
WGE 27.-29. September 2011 15Brit Lisa Skjelkvåle
Biological recoveryRegion Country Biota period Trends recovery potential
reached?
North Nordic Finland Fish 1985-2007 no informationPeriphyton n.d. yes
South Nordic Norway Zoobenthos 1982-2010 no
Sweden Phytoplankton 1988-2008 no
Zoobenthos 1988-2008 no
Finland Fish 1985-2007 no
Zoobenthos n.d. noPeriphyton n.d. no
East Central Europe Czech rep. Phytoplankton 1990-2009 no
Zooplankton 1990-2009 noZoobenthos 1990-2009 noMacrophytes 2004-2010 no
Alps Switzerland Zoobenthos 2000-2009 no informationZoobenthos 2000-2009 no information
West Central Europe Germany Zoobenthos 1982-2010 no
1982-2010 noGermany Zoobenthos
WGE 27.-29. September 2011 16Brit Lisa Skjelkvåle
Conclusions• Improvements in acidification of surface waters are related to lower
acid deposition
• The reductions of acidifying components in precipitation are larger and quicker than the observed improvements in water chemistry
• Increase in pH, alkalinity and ANC indicate that biological recovery can be expected
• Biological recovery is documented in many regions in Europe
– Full recovery is not documented anywhere.
– A return to pre-industrial biodiversity is unlikely
• Several areas in Europe will never achieve good (non-acidified) water quality with current legislation of emissions of acidifying components.
• Future reductions of both S and N deposition would be necessary to achieve biological recovery not influenced by acidification.
WGE 27.-29. September 2011 17Brit Lisa Skjelkvåle
The last 50 years
• 60s – 70s: increase in deposition - severe acidification – fish deaths – forest dieback – concerns leading to establishment of the LRTAP Convention
• 80s : decrease in deposition - small (no) changes in water chemistry and no changes in biota
• 90s : large decrease in deposition - large changes in water chemistry and small positive changes (recovery) in biota
• 00s : less decrease in deposition - chemical recovery is slowing down, more signs of biological recovery, but ecosystems are still fragile
WGE 27.-29. September 2011 18Brit Lisa Skjelkvåle
www.icp-waters.nothe report will be avilable in October