wge 27.-29. september 20111brit lisa skjelkvåle trends in precipitation chemistry, surface water...

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


Aim of the report

• Describe the changes in acid sensitive aquatic ecosystems in Europe and North America due to emission reductions


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?


Chain of effects

Emission reductions of S and N

changes in precipitation chemistry

changes in water chemistry

possible effects on aquatic biota (recovery)


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


Time spans in the report

1990 – 1999 = 90s1999 – 2008 = 00s

and the whole period together1990 - 2008


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


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


EMEP CCC monitoring network used for the analysis


ICP Waters network

Chemistry at all sitesBiology at selected sites and not in all countries


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

÷÷

÷

÷

÷

÷

÷

÷

+

+

+

÷


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


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


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


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


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.


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


www.icp-waters.nothe report will be avilable in October

wge 27.-29. september 20111brit lisa skjelkvåle trends in precipitation chemistry, surface water...

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