Acknowledgements ................................................ i
Summary ....................................................... iii
1 Introduction and Objectives .................................. 1
1.1 Chemical pollution in freshwater ecosystems ............. 1
1.2 Chemical Risk Assessment ................................ 2
1.3 Predicting the sensitivity of species using
evolutionary concepts ................................... 5
1.4 Large-scale assessment of freshwater ecosystems ......... 6
1.5 Co-occurrence of stressors .............................. 7
1.6 Objectives and structure of the thesis .................. 8
2 Physiological Sensitivity of Freshwater Macroinvertebrates
to Heavy Metals ............................................. 15
2.1 Abstract ............................................... 17
2.2 Introduction ........................................... 17
2.3 Methods ................................................ 19
2.3.1 Database Compilation ............................ 19
2.3.2 Normalization of the toxicity data .............. 21
2.3.3 Calculation of physiological sensitivity to
heavy metals .................................... 22
2.3.4 Statistical Analysis ............................ 22
2.4 Results ................................................ 23
2.4.1 Normalization of the toxicity data .............. 23
2.4.2 Relationship of physiological sensitivity for
different heavy metals .......................... 24
2.4.3 Physiological sensitivity to heavy metals
(Smetal) ........................................ 25
2.5 Discussion ............................................. 32
2.5.1 Similarities in the physiological sensitivity
of heavy metals ................................. 32
2.5.2 Physiological sensitivity to heavy metals
(Smetal) ........................................ 32
2.5.3 Application of physiological sensitivity to
heavy metals in ecological risk assessment ...... 33
3 Evolutionary Patterns and Physicochemical Properties
Explain Macroin-vertebrate Sensitivity to Heavy Metals ...... 39
3.1 Abstract ............................................... 41
3.2 Introduction ........................................... 41
3.3 Methods ................................................ 42
3.3.1 Data Mining ..................................... 42
3.3.2 Construction of the phylogenetic tree ........... 43
3.3.3 Phylogenetic bilinear models .................... 43
3.4 Results ................................................ 47
3.4.1 Sensitivity to heavy metals ..................... 47
3.4.2 Phylogenetic Tree ............................... 48
3.4.3 Bilinear Models ................................. 48
3.5 Discussion ............................................. 49
3.5.1 Influence of inter-species variation ............ 50
3.5.2 Influence of physicochemical properties ......... 50
3.5.3 Influence of molecular information .............. 51
3.5.4 Implications for ecological risk assessment ..... 51
4 Organic Chemicals Jeopardize the Health of Freshwater
Ecosystems on the Continental Scale ......................... 57
4.1 Abstract ............................................... 59
4.2 Introduction ........................................... 59
4.3 Methods ................................................ 60
4.3.1 Data mining ..................................... 60
4.3.2 Threshold selection ............................. 61
4.3.3 Chemical risk calculation ....................... 61
4.3.4 Acute-Risk Chemicals ............................ 62
4.3.5 Temporal Variation .............................. 62
4.3.6 Land Use Practices .............................. 62
4.3.7 Ecological status ............................... 62
4.4 Results and Discussion ................................. 63
4.4.1 Chemical Risk ................................... 63
4.4.2 Contributors to chemical risk ................... 65
4.4.3 Chemical risk and land use ...................... 66
4.4.4 Underestimation of chemical risk ................ 67
4.4.5 Ecological status and the relationship with
chemical risk ................................... 67
4.4.6 Conclusions and prospective ..................... 69
5 How Much do Organic Toxicants Contribute to Multiple
Stress in Fresh-water Ecosystems? ........................... 75
5.1 Abstract ............................................... 77
5.2 Introduction ........................................... 77
5.3 Methods ................................................ 79
5.3.1 General rationale ............................... 79
5.3.2 Stream network including stream typology and
ecoregion ....................................... 79
5.3.3 Stream order .................................... 79
5.3.4 Habitat degradation and risk thresholds ......... 80
5.3.5 Invasive species and risk thresholds ............ 80
5.3.6 Nutrients and risk thresholds ................... 80
5.3.7 Organic toxicants and risk thresholds ........... 81
5.3.8 Combination of data sets ........................ 81
5.3.9 Data analysis ................................... 82
5.4 Results ................................................ 82
5.4.1 Frequency of stressors in the sampling sites
and joint occurrences ........................... 82
5.4.2 Association among stressors and with stream
type and order .................................. 83
5.5 Discussion ............................................. 83
5.5.1 Stressor occurrence and caveats ................. 83
5.5.2 Relevance of stressors and management of
multiple stress ................................. 85
6 General Discussion .......................................... 95
6.1 Tools in ecotoxicology ................................. 95
6.1.1 Sensitivity to heavy metals: Applications and
limitations ..................................... 95
6.1.2 Evolutionary patterns explain sensitivity to
heavy metals .................................... 96
6.2 Likelihood of effects from organic chemicals ........... 97
6.2.1 Effect thresholds ............................... 97
6.2.2 How much complexity is feasible? ................ 97
6.2.3 Minimum Risk from Chemicals ..................... 98
6.2.4 Ecological status of freshwater ................. 98
6.2.5 Multiple stressors in freshwater ................ 99
6.3 Future challenges ..................................... 100
A Supplementary information for: Physiological Sensitivity
of Freshwater Macroinvertebrates to Heavy Metals ........... 107
A.l Supplementary Methods .................................. 107
A.1.1 Normalization of the toxicity data ............. 107
A.2 Supplementary Figures .................................. 108
A.3 Supplementary Tables ................................... 110
В Supplementary information for: Evolutionary Patterns and
Physico-chemical Properties Explain Macroinvertebrate
Sensitivity to Heavy Metals ................................ 119
B.l Supplementary Methods ................................. 119
B.l.l Physicochemical properties ..................... 119
B.2 Supplementary Figures ................................. 121
B.3 Supplementary Tables .................................. 122
С Supplementary information for: Organic chemicals
jeopardize the health of freshwater ecosystems on the
continental scale .......................................... 129
C.l Supplementary Methods ................................. 129
C.l.l Chemical data .................................. 129
C.l.2 Concentrations for acute and chronic exposure .. 130
C.1.3 Toxicity data .................................. 131
C.l.4 Threshold selection for the assessment of
chemical risk .................................. 132
C.l.5 Likelihood definition .......................... 133
C.l.6 Suitability of reported limits of
quantification for chemical risk assessment .... 133
C.l.7 Influence of acute-risk chemicals (ARCs) on
chemical risk .................................. 133
C.2 Supplementary Discussion .............................. 134
C.2.1 Influence of hydrophobic compounds on
chemical risk .................................. 134
C.3 Supplementary Figures ................................. 136
C.4 Supplementary Tables .................................. 140
D Supplementary information for: How Much do Organic
Toxicants Contribute to Multiple Stress in Freshwater
Ecosystems? ................................................ 159
D.l Supplementary Figures ................................. 161
D.2 Supplementary Tables .................................. 165
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