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Mercury in Wild Mink of the Lower Great Lakes Basin, Canada, 1998-2006

www.ec.gc.ca. Mercury in Wild Mink of the Lower Great Lakes Basin, Canada, 1998-2006. P.A. Martin, T.V. McDaniel, & K.D. Hughes , Environment Canada, Burlington ON. American Mink – A Great Lakes Sentinel.

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Mercury in Wild Mink of the Lower Great Lakes Basin, Canada, 1998-2006

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  1. www.ec.gc.ca Mercury in Wild Mink of the Lower Great Lakes Basin, Canada, 1998-2006 P.A. Martin, T.V. McDaniel, & K.D. Hughes, Environment Canada, Burlington ON

  2. American Mink – A Great Lakes Sentinel • wide geographic distribution & captured in sufficient numbers (NA: 400-700k/yr, est. 10 million population) • restricted linear home range (1-5km) • Prey generalist, but ~50% diet is fish (bioaccumulate aquatic pollutants) • Sensitive to many pollutants, especially methylmercury (MeHg), MeHg-related effects (biochemistry, lesions, behavior) similar to other wildlife and humans • declines in wild mink populations associated with MeHg pollution • studied in nature and the laboratory

  3. Mercury in Mink Liver (n=156)13 Great Lakes Basin Sites, 1998-2006 -Blue bars = shoreline animals (<8km) -Green = inland ref (8-40km) -[Hg] highest in marsh environments - Plotted N/W to S/E (trend?)

  4. Total Mercury & % Methylmercury in Mink Liver -MeHg in 51/156 -confirm previous results

  5. Total Mercury & Selenium in Mink Liver -strong correlation -confirm previous results

  6. Total Mercury & Selenium - Mink Age -canine dental cementum = 3 age classes -youngest had lowest Hg (confirm some past works)

  7. Conclusions – Pt1 • Significant variation in hepatic total mercury levels found among Great Lakes mink with the highest mean levels in mink trapped in locations associated with marsh environments. • Unclear relative influences of mercury sources derived from marshes, which can be natural sites of mercury methylation particularly following flooding (impoundments) as well possible industrial sources. • Total mercury negatively related to % methylmercury and positively related to selenium, consistent with increasing demethylation of methylmercury with increasing total mercury concentrations.

  8. Conclusions– Pt2 • Total mercury levels in mink are consistently below 25 µg/g ww threshold associated with overt mercury toxicity. • A significant age effect was found for both mercury and selenium. • Mercury levels were unrelated to rates infestation with internal parasites.

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