Last Updated October 8, 2017

Northern Contaminants Program

Canadian Arctic Contaminants Assessment Report II (2003)

Volume 4: Contaminant Levels, Trends and Effects in the Biological Environment

Full Document


Executive Summary     i

Résumé     v


Part I     1


1 Introduction     3

1.1 Background 3

1.2 Study design 4


2 Pathways and Processes of Delivery of Contaminants to Marine, Freshwater and Terrestrial Ecosystems     7

2.1 Inputs of airborne and seaborne contaminants 7

2.2 Bioaccumulation processes 8


3 Contaminants in Biota — Levels and Spatial Trends     11

3.1 Spatial trends of contaminants in freshwater biota 11

3.1.1 Spatial trends of metals in freshwater fish 11

3.1.1.1 Factors influencing metals in freshwater fish 12

3.1.1.2 Spatial trends of metals in freshwater fish 14

3.1.2 Levels and spatial trends of organochlorines in freshwater fish 17

3.1.3 Levels of new chemicals in freshwater fish 20

3.1.4 Overall assessment of contaminants in freshwater biota 20

3.2 Terrestrial biota — levels and spatial trends 21

3.2.1 Contaminants in caribou and other big game mammals 21

3.2.2 Levels of organochlorines and metals in mammals associated with freshwater 23

3.2.3 Spatial trends of contaminants in waterfowl and game birds 23

3.2.4 Contaminants in plants 25

3.2.5 Local sources of contaminants in the terrestrial environment 26

3.2.6 Overall assessment of contaminants in terrestrial biota 26

3.3 Spatial trends of contaminants in marine biota 27

3.3.1 Contaminants in invertebrates and marine fish 27

3.3.1.1 Metals in invertebrates and fish 28

3.3.1.2 Organochlorines in invertebrates and fish 29

3.3.2 Spatial trends of contaminants in seabirds 32

3.3.2.1 Metals in seabirds 32

3.3.2.2 Organochlorines in seabirds 36

3.3.2.3 New chemicals in seabirds 37

3.3.3 Spatial trends of contaminants in marine mammals 38

3.3.3.1 Levels and spatial trends in metals in marine mammals 39

3.3.3.2 Organochlorines in marine mammals 41

3.3.3.3 New compounds in marine mammals 49

3.3.4 Arctic marine food web studies 52

3.3.4.1 Trophic transfer of metals in marine food webs 53

3.3.4.2 Trophic transfer of organochlorines in marine food webs 54

3.3.4.3 Trophic transfer of new and chiral chemicals in marine food webs 56

3.3.4.4 Trophic transfer of organochlorine metabolites in marine food webs 56

3.3.5 Local sources of contaminants in the marine environment 56

3.3.6 Overall assessment of contaminants in marine biota 58


4 Temporal Trends of Contaminants in Biota      63

4.1 Temporal trends of contaminants in freshwater fish 63

4.1.1 Metals in freshwater fish 64

4.1.2 Organochlorines in freshwater fish 66

4.1.3 Overall assessment of temporal trends of contaminants in freshwater fish 68

4.2 Temporal trends of contaminants in seabirds 69

4.2.1 Conclusions on temporal trends of contaminants in seabirds 70

4.3 Temporal trends of contaminants in marine mammals 71

4.3.1 Organochlorines in marine mammals 71

4.3.2 New chemicals in marine mammals 77

4.3.3 Metals in marine mammals 78

4.3.4 Modelling temporal trends of organochlorines in pinnipeds and cetaceans 81

4.3.5 Overall assessment of temporal trends of contaminants in marine biota 83


5 Biological Effects     87

5.1 Introduction 87

5.2 Effects studies 88

5.2.1 Eider ducks 88

5.2.2 Black guillemot nestlings at Saglek, Labrador 91

5.2.3 Mercury toxicity in beluga 91

5.2.4 Toxicity in polar bears 92

5.3 Comparison of thresholds of biological effects and concentrations observed in Canadian Arctic biota 94

5.3.1 Organochlorine concentrations and threshold levels of effects 94

5.3.2 Metals concentrations and threshold levels of effects 98

5.4 Assessment of biological effects work in Canadian Arctic biota 99


6 Conclusions and Knowledge Gaps, and Recommendations     103

6.1 Conclusions 103

6.1.1 Priority chemicals 103

6.1.2 Spatial trends 103

6.1.3 Temporal trends 104

6.1.4 Biological effects 105

6.2 Knowledge gaps and recommendations 105

6.2.1 Priority chemicals 105

6.2.2 Spatial trends and geographic coverage 106

6.2.3 Temporal trends 107

6.2.4 Biological effects 107


Part II     109


7 Interlaboratory Quality Assurance for the Northern Contaminants Program     111

7.1 Introduction 111

7.2 Background 111

7.3 Interlaboratory comparison studies 113

7.4 Data assessment techniques 113

7.5 Results of the intercomparison studies 114

7.5.1 Toxic heavy metals in sediments 114

7.5.2 Heavy metals and methylmercury in biotic samples 115

7.5.3 Organochlorines and PCBs 117

7.5.4 Toxaphene 121

7.5.5 Radionuclides 123

7.5.6 Stable lead isotopes 123

7.5.7 Organotins 124

7.5.8 Chemicals of emerging concern 125

7.6 Overall analytical data quality within the NCP QA program 125

7.7 Summary and next steps 126


References     129