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“Our waters, our fish, our people”. Mercury contamination in fish resources of two Treaty #3 communities. Research Question. Do our fish still contain high levels of Hg? Is it possible that some fish species in some lakes are clean enough to eat?
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“Our waters, our fish, our people” Mercury contamination in fish resources of two Treaty #3 communities
Research Question • Do our fish still contain high levels of Hg? • Is it possible that some fish species in some lakes are clean enough to eat? • How much fish can we eat without the fear of Hg poisoning? • Can we set up a monitoring program ourselves to check the Hg levels in fish?
7.000 6.000 Ball lake Clay lake 5.000 Garden Indian lake Maynard lake 4.000 Separation Tide lake 3.000 Ball Lake trendline 2.000 1.000 0.000 20 30 40 50 60 70 80 90 length (cm) Walleye
0.600 0.500 Ball lake Clay lake Clay Lake Trendline Garden lake 0.400 Indian lake Maynard lake Separation lake Tide lake 0.300 0.200 0.100 0.000 35 40 45 50 55 60 length (cm) Whitefish
7.000 6.000 Ball lake 5.000 Clay lake Indian lake Maynard lake Separation lake 4.000 Clay Lake Trendline 3.000 2.000 1.000 0.000 15 20 25 30 35 40 45 50 length (cm) Bass
7.000 6.000 Ball lake Clay lake 5.000 Indian lake Garden lake Separation lake 4.000 Tide lake Maynard 3.000 Clay Lake Trendline 2.000 1.000 0.000 30 40 50 60 70 80 90 100 110 length (cm) Northern Pike
Clay Lake Ball Lake Clay Lake Indian Lake Indian Lake Tetu Lake Ball Lake Mercury Contamination in Walleye 18 16 14 Concentraton Hg (ug/g) 12 10 1973 2003 8 6 4 2 0 0 20 40 60 80 100 120 140 160 180 200 distance downstream from Dryden (miles)
Table 20: Average Hg Levels Fishing Popularity of Specific Lakes
Table 20: Average portion size for a fish meal (g/meal) (mean ± SD)
Average Mercury Exposure by Age and Gender Group – Grassy Narrows
Distribution of Mean Hair Mercury Concentrations – Grassy Narrows
Estimated Mercury Exposure and Measured Hair Level - Grassy Narrows
Profile of participants with high Hg intake in Grassy Narrow
RecommendationGrassy Narrow • Currently, there is no problem with high Hg exposure from eating fish • Do not eat fish from Clay and Ball Lake • Promote eating more fish, particularly whitefish up to 5 fish meal per week • Walleye may be limited to 2 fish meal every 3 weeks for those who are concerned.