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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Ward De Coomanw.decooman@vmm.bewww.vmm.be