Mercury and Fish in the Adirondack Lakes

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Mercury and Fish in the Adirondack Lakes
Jason Dittman Dr. Charles Driscoll Syracuse
University
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Background

• Regional Fish Survey 1992-93
• - 26 lakes in the Adirondacks.
• - Fish and water column Hg sampling.

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1992-1993 Results
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Fish Hg Concentrations 1992-1993
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Summary of 1992-1993 Study

• Elevated concentrations of fish Hg
• As pH declined, Hg increased
• 34 of perch exceeded 0.3 ug/g level
• 96 of the lakes exceed 0.3 ug/g level
• DOC plays a complex role
• Other factors such as pH, Al, redox conditions,
  fish age, and food source

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Anthropogenic U.S. Hg emissions
Source www.epa.gov/mercury.com
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2005-2006

• Resurvey original 26 Lakes
• Water column Hg ancillary.
• Fish yellow perch (Perca flavescens)
• 3. Zooplankton Clarkson University

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Study Objectives

1. Evaluate changes in water column and fish mercury
   (Hg) concentrations from 1992-2006.
2. Evaluate potential mechanisms contributing to
   observed changes from 1992-2006.
3. Compare water column and fish Hg concentrations
   across a gradient of lakes.

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Water Chemistry
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Yellow Perch (Perca flavescens)
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Fish Analysis Methods
Dermal Punch
Plug of Fish Tissue
Direct Hg Analyzer
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2005-2006 Survey

• Worked completed to date
• All 26 lakes have been resurveyed.
• Water chemistry analysis complete.
• Fish tissue analysis in progress
• 1200 fish

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Conclusion

• The acid-base status of lakes surveyed has
  improved over the past decade.
• Water column HgT MeHg has decreased since
  1992.
• Fish Hg has declined since 1992.
• - degree of decline is lake dependent
  (geochemical characteristics).
• A better picture of the actual response will be
  gained by including 2006 fish data.

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Future Work

• Selection of 6 lakes for intensive study
• Mercury Cycling Model for Headwater Drainage
  Lakes(MCM-HD) model

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Acknowledgements

• Field work
• Adirondack Lake Survey Corporation
• Laboratory work
• Mario Montesdeoca
• Ed Mason
• Colin Fuss
• Sharon Quimby

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References

• Driscoll, C.T, Yan, C., Schofield, C.L., Muson,
  R., Holsapple, J. 1994. The Mercury Cycle and
  Fish in the Adirondack Lakes. Environ. Sci.
  Technol. Vol. 28 136A -143A.
• Driscoll, C.T., Blette, V., Yan, C., Schofield,
  C.L., Munson, R., and Holsapple, J. 1995. The
  role of dissolved organic carbon in the chemistry
  and bioavailability of mercury in remote
  Adirondack lakes. Water Air Soil Pollution 80
  499-508.
• U.S. Environmental Protection Agency mercury
  website www.epa.gov/mercury.