Characterizing the risks to aquatic ecosystems: A tentative approach in the context of freshwater dredged material disposal

Authors

  • Marc P. Babut,

    Corresponding author
    1. Cemagref, Freshwater Ecosystems Biology Research Unit, Ecotoxicology Laboratory, 3 bis Quai Chauveau—CP 220, 69336 Lyon Cedex, France
    • Cemagref, Freshwater Ecosystems Biology Research Unit, Ecotoxicology Laboratory, 3 bis Quai Chauveau—CP 220, 69336 Lyon Cedex, France
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  • Hélène Delmas,

    1. Cemagref, Freshwater Ecosystems Biology Research Unit, Ecotoxicology Laboratory, 3 bis Quai Chauveau—CP 220, 69336 Lyon Cedex, France
    2. ENTPE, Laboratoire des Sciences de l'Environnement, Ecole Nationale des Travaux Publics de l'Etat, rue Maurice Audin, 69518 Vaulx-en-Velin, France
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  • Marc Bray,

    1. Cemagref, Freshwater Ecosystems Biology Research Unit, Ecotoxicology Laboratory, 3 bis Quai Chauveau—CP 220, 69336 Lyon Cedex, France
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  • Claude Durrieu,

    1. ENTPE, Laboratoire des Sciences de l'Environnement, Ecole Nationale des Travaux Publics de l'Etat, rue Maurice Audin, 69518 Vaulx-en-Velin, France
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  • Yves Perrodin,

    1. ENTPE, Laboratoire des Sciences de l'Environnement, Ecole Nationale des Travaux Publics de l'Etat, rue Maurice Audin, 69518 Vaulx-en-Velin, France
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  • Jeanne Garric

    1. ENTPE, Laboratoire des Sciences de l'Environnement, Ecole Nationale des Travaux Publics de l'Etat, rue Maurice Audin, 69518 Vaulx-en-Velin, France
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Abstract

The development of relevant frameworks for assessing ecological risks posed by dredged material management does not only involve an appropriate selection of assessment and measurement endpoints but also requires a sound approach to both risk characterization and the associated uncertainty. A formal methodology addressing both aspects has been developed in France for freshwater sediment deposits in water. Both exposure and effects measurements are 1 st transformed into scores or classes. As far as possible, class boundaries are based on existing knowledge or expertise. Benthic organism exposure is based on a ratio of the deposit area to the burrow pit area, whereas pelagic species exposure is based on the ratio of porewater volume to water column volume. The combination of exposure and effect scores yields risk scores, or classes, which are linked to management decisions. Uncertainty is assessed with respect to a set of 4 predetermined criteria for exposure (the strength of association with the assessment endpoint, spatial and temporal representativeness, and the use of standard methods) and 4 criteria for effects (strength of association, the distinction between effect and no effect, sensitivity, and the use of standard methods). This approach was applied to 8 sediments from French canals contaminated to varying degrees.

EDITOR'S NOTE:

The following represents supplemental data and information provided by the author to support the research reported in IEAM 2(4):330–343.

Appendix Table

Table Appendix Table.. Ranks and scores for a score ordination approach on the basis of 4 criteria and 3 modalitiesa
ABCDRankScore
  1. a H = high; M = medium; L = low.

HHHH10.12
HHHM20.25
HHHL30.37
HHHH40.49
HHMM50.62
HHML60.74
HHLH70.86
HHLM80.99
HHLL91.11
JMHH101.23
HMHM111.36
HMHL121.48
HMMH131.60
HMMM141.73
HMML151.85
HMLH161.98
HMLM172.10
HMLL182.22
HLHH192.35
HLHM202.47
HLHL212.59
HLMH222.72
HLMM232.84
HLML242.96
HLLH253.09
HLLM263.21
HLLL273.33
MHHH283.46
MHHM293.58
MHHL303.70
MHMH313.83
MHMM323.95
MHML334.07
MHLH344.20
MHLM354.32
MHLL364.44
MMHH374.57
MMHM384.69
MMHL394.81
MMMH404.94
MMMM415.06
MMML425.19
MMLH435.31
MMLM445.43
MMLL455.56
MLHH465.68
MLHM475.80
MLHL485.93
MLMH496.05
MLMM506.17
MLML516.30
MLLH526.42
MLLM536.54
MLLL546.67
LHHH556.79
LHHM566.91
LHHL577.04
LHMH587.16
LHMM597.28
LHHL607.41
LHML617.53
LHLM627.65
LHLL637.78
LMHH647.90
LMHM658.02
LMHL668.15
LMMH678.27
LMMM688.40
LMML698.52
LMLH708.64
LMLM718.77
LMLL728.89
LLHH739.01
LLHM749.14
LLHL759.26
LLMH769.38
LLMM779.51
LLML789.63
LLLH799.75
LLLM809.88
LLLL8110.00

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