ecological characterisation of sediments (flanders) · ecological characterisation of sediments...
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Ecological characterisation of sediments (Flanders)
Ward De Cooman
Flemish Environment AgencyDivision Reporting Water
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• Definitions, research & milestones• Monitoring Quality Network: why – how• Triad-approach• D-base – Geoview – mapping• SQC
Content
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Belgium and Flanders in Europe
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Flemish Environment Agency
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Definitions sediment• Natural sediment:
• part of aquatic ecosystem underneath sedimentlayer, or the ecological soil of the region (sand, clay, loam)
• Sediment (active layer):• disposed suspended
sediments (sedimentlayer).
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Milestones of the last 17 years
1994 1995 20042000 2008
characterisationStudy - Triade
StartSediment Monitoring Network
Campagne I 600 sampling points
Campagne II 600 ssampling points
Mile
sto
nes
2007
Sediment-Dbase (Ql)
2006
Sediment Quality Standards/guidelines
Extended module in D-Base: Quantity aspects (Qn)
MethodologicalStudy - Triade
2005
New sampling technique with Beekersampler
Study on the Rehabilitation of a case(Dommel)
Extra sampling in the contextOf dredging programs
Research on the qualityOf Suspended Solids 2009-2010-2011
Monitoring of sediment quantity
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Why monitoring??
• Collecting abiotic and biotic information of the aquatic ecosystem
• Sediment quality/quantity inventory with respect to
• integrated water management
• sediment policy
• international reporting of sediment quality
• Reporting sediment quality/Quantity (on maps)
• Assessment changes before and after dredging programs
• Evaluation environmental policy
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Sediment quality/quantity inventory
Sampling
• Van Veen grap sampler (2 liter/6 liter)• Zig zag sampling in 50 meter zones or
stratified ad random sampling• 20-70 subsamples• Mixed sample : ~40 à 50 liter
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TRIAD approach
• Fysico-chemical analyses• chemical content• but: bioavailability or effects
• Ecotoxicological analyses:• effects• but: extrapolation to field conditions
• Biological analyses:• effects on in situ benthic community• but: effects of other ecological factors
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TRIAD-approach
Ecological quality of sedimentsTRIAD-concept
Fysico-chemical analyses
Ecotoxicology
Biology
Degree of contamination
Chemical composition
Acute effects of sedimenst on test-
organisms (bioassays)
Sediment as an environment for
benthic organisms
Fractions, Organic matter,Mineral oil, Heavy metals,OCP’s,PAH’s,PCB’s.
Fysico-chemical parameters:
Solid-phase test:• Hyalella azteca
Ecotoxicological parameters:
Liquid-phase test: • Raphidocelis subcapitata
Biological parameter: Biotic Sedimentindex (BSI): presence of indicatororganisms and taxonomic diversity
Benthic macro-invertebrates
Liquid-phase test: • Thamnocephalus
platyurus
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Triad Assessment of 600 points (2006-2009)
Ecological characterisation of sediments in Flanders
Integrated results
1%
25%
39%
35%
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
2000-2003 2004-2007 2008-2009
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Fysico-chemical assessment
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
As t Cd t Cr t Cu t Hg t Ni t Pb t Zn t EAS
tce
EOX OCP t PAK 6 PCB t
strongly contaminated
contaminated
slightly contaminated
not contaminated
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Sediment Quality Criteria
Bad
Moderate
Poor
Good
High
C2
C1
A
B
biological abundances (LEL and SEL)
ecotoxicological thresholds(TEL and PEL)
Consensus between:
(de Deckere et al, 2011, JSS, 11: 504-517)
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