Increased Methylmercury Contamination in Fish in Newly Formed Freshwater Reservoirs

  • R. E. Hecky
  • D. J. Ramsey
  • R. A. Bodaly
  • N. E. Strange
Part of the Rochester Series on Environmental Toxicity book series (RSET)


The formation of major new hydroelectric reservoirs in northern Canada in the last two decades was invariably followed by increased methylmercury concentrations in fish. Concentrations in piscivorous fish exceeded marketing limits and often approached mercury concentrations (>5 μg g−1 wet weight) in muscle formerly associated only with industrial mercury pollution. Experimental manipulations of large enclosures demonstrated that terrestrial vegetation and organic soils caused increased net methylation of mercury and bioaccumulation of methylmercury at low total mercury concentrations in water (1–2 ng L−1) and sediment (0.1–1.0 μg g−1 dry weight). Total mercury concentrations per se in water or sediments did not predict mercury concentrations in fish. Enhancement of microbial methylation relative to demethylation can be demonstrated in these new reservoirs and in reservoirs up to 60 years of age. Disruption of the natural microbially mediated mercury cycle accounts for the elevated Hg concentrations in fish, and indications are that it will be a persistent problem in boreal reservoirs. The reservoir experience emphasizes the critical role of microbial activity in mercury cycling. In natural lakes of the boreal forest, water temperaturc seems to be a critical variable controlling net mercury methylation by microbial activity.


Mercury Concentration Yellow Perch Mercury Methylation Total Mercury Concentration Mercury Uptake 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Abernathy, A. R. and Cumbie, P.M., 1977. Mercury accumulation by largemouth bass (Micropterus salmoides) in recently impounded reservoirs. Bull. Environ. Contain. Toxicol. 17:595–602.CrossRefGoogle Scholar
  2. Berman, M. and Bartha, R., 1986. Levels of chemical versus biological methylation of mercury in sediments. Bull. Environ. Contam. Toxicol. 36:402–404.CrossRefGoogle Scholar
  3. Bloom, N. S. and Watras, C. J., 1989. Observations of methylmerjcury in precipitation. Sci. Total Environ. 87/88:199–207.CrossRefGoogle Scholar
  4. Bodaly, R. A., Hecky, R. E. and Fudge, R. J. P., 1984. Increases in fish mercury levels in lakes flooded by the Churchill River diversion, northern Manitoba. Can. J. Fish. Aquat. Sci. 41:682–691.CrossRefGoogle Scholar
  5. Bodaly, R. A. and Hecky, R. E., 1979. Post-impoundment increases in fish mercury levels in the Southern Indian Lake reservoir. Manitoba Can. Fish Mar. Serv. Manuscr. Rep. 1531:iv+15 p.Google Scholar
  6. Bodaly, R. A., Strange, N. E., Hecky, R. E., Fudge, R. J. P. and Anema, C., 1987. Mercury content of soil, lake sediment, net plankton, vegetation, and forage fish in the area of the Churchill River diversion, Manitoba, 1981–82. Can. Data Rep. of Fish. Aquat. Sci. 610:iv+33 p.Google Scholar
  7. Canada-Manitoba Mercury Agreement. 1987. Summary Report. Canada Manitoba Agreement on the Study and Monitoring of Mercury in the Churchill River Diversion. Winnipeg, Canada.Google Scholar
  8. D’Itri, F. M., 1972. The Environmental Mercury Problem, The Chemical Rubber Co., Cleveland, Ohio.Google Scholar
  9. Fitzgerald, W. F. and Watras, C. J., 1989. Mercury in surficial waters of rural Wisconsin lakes. Sci. Total Environ. 87/88:223–232.CrossRefGoogle Scholar
  10. Furukawa, K., Suzuki, T. and Tonomura, K., 1969. Decomposition of organic mercurial compounds by mercury-resistant bacteria. Agric. Biol. Chem. 33:128–130.CrossRefGoogle Scholar
  11. Furutani, A. and Rudd, J. M. W., 1980. Measurement of mercury methylation in lake water and sediment samples. Appl. Environ. Microbiol. 40:770–776.PubMedGoogle Scholar
  12. Hecky, R. E., 1987. Methylmercury contamination in northern Canada. Northern Perspectives 15(3):8–9.Google Scholar
  13. Hecky, R. E., Bodaly, R. A., Ramsey, D. J., Ramlal, P. S. and Strange, N. E., 1987b. Evolution of limnological conditions, microbial methylation of mercury and mercury concentrations in fish in reservoirs of northern Manitoba, Canada-Manitoba Agreement on the Study and Monitoring of Mercury in the Churchill River diversion. Summary Report. Appendix 3:53 p. + 5 appendices.Google Scholar
  14. Hecky, R. E., Bodaly, R. A., Strange, N. E., Ramsey, D. J., Anema, C. and Fudge, R. J. R, 1987a. Mercury bioaccumulation in yellow perch in limnocorrals simulating the effects of reservoir formation. Can. Data Rep. Fish Aquat. Sci. 628:v+158 p.Google Scholar
  15. Hecky, R. E., Newbury, R. W., Bodaly, R. A., Patalas, K. and Rosenberg, D. M., 1984. Environmental impact prediction and assessment: the Southern Indian Lake experience. Can. J. Fish Aquat. Sci. 41:720–732.CrossRefGoogle Scholar
  16. Jensen, S. and Jernelov, A., 1969. Biological methylation of mercury in aquatic organisms. Nature (London) 223:753–754.CrossRefGoogle Scholar
  17. Joensuu, O. I., 1971. Fossil fuels as a source of mercury pollution. Science 172:1027–1028.PubMedCrossRefGoogle Scholar
  18. Newbury, R. W., McCullough, G. K. and Hecky, R. E., 1984. The Southern Indian Lake impoundment and Churchill River diverison. Can. J. Fish Aquat. Sci. 41:548–557.CrossRefGoogle Scholar
  19. Ramlal, P. S., Rudd, J. W. M. and Hecky, R. E., 1986. Methods of measuring specific rates of mercury methylation and degradado and their uses in determining factors controling net rates of mercury methylation. Appl. Environ. Microbiol. 51:110–114.PubMedGoogle Scholar
  20. Ramlal, P. S., Anema, C., Furutani, A., Hecky, R. E. and Rudd, J. W. M., 1987. Mercury methylation and demethylation studies at Southern Indian Lake, Manitoba: 1981–1983. Can. Tech. Rep. Fish Aquat. Sci., 1490:v+35 p.Google Scholar
  21. Ramsey, D. M., 1990a. Experimental studies of mercury dynamics in the Churchill River diversion, Manitoba. Collection Environment et Geologie, 9:147–173.Google Scholar
  22. Ramsey, D. M., 1990b. Measurements of methylation balance in Southern Indian Lake, Granville Lake, and Stephens Lake, Manitoba, 1989. Northern Flood Agreement Federal Environmental Monitoring Program Rep. (in press).Google Scholar
  23. Robinson, J.B., and Tuovinen, O.H., 1984. Mechanisms of microbial resistance and detoxification of mercury and organomercury compuonds: physiological, biochemical, and genetic analyses. Microbiol. Reviews 48:95–124.Google Scholar
  24. Rodgers, D.W. and Beamish, F.W., 1981. Uptake of waterborne methylmercury by rainbow trout (Salmo gairdneri) in relation to oxygen consumption and methylmercury concentration. Can. J. Fish Aquat. Sci. 38:1309–1315.CrossRefGoogle Scholar
  25. Rodgers, D.W. and Beamish, F.W., 1982. Dynamics of dietary methylmercury in rainbow trout (Salmo gairdneri), Aquat. Toxicol. 2:271–290.CrossRefGoogle Scholar
  26. Rodgers, D.W. and Beamish, F. W., 1983. Water quality modifies uptake of waterborne methylmercury by rainbow trout (Salmo gairdneri). Can. J. Fish Aquat. Sci. 40:824–828.CrossRefGoogle Scholar
  27. Rudd, J.W.M., Furtani, A. and Turner, M., 1980. Mercury methylation by fish intestinal contents. Appl. Environ. Microbiol. 40(4):777–782.PubMedGoogle Scholar
  28. Rudd, J.W.M., Turner, M.A., Furutani, A., Swick, A. and Townsend, B.E., 1983. A synthesis of recent research with a view towards mercury amelioration. Can. J. Fish Aquat. Sci. 40:2206–2217.CrossRefGoogle Scholar
  29. Wiener, J.G., Fitzgerald, W.F., Watras, CJ. and Rada, R.G., 1990. Partitioning and bioavailability of mercury in an experimentally acidified lake. Environ. Toxicol. Chem. 9:909–918.CrossRefGoogle Scholar
  30. Winfrey, M.R. and Rudd, J.W.M., 1990. Environmental factors affecting the formation of methylmercury in low pH lakes: a review. Environ. Contam. Toxicol. 9:853–869.Google Scholar
  31. Wright, D.R. and Hamilton, R.D., 1982. Release of methylmercury from sediments: effects of mercury concentration, low temperature, and nutrient addition. Can. J. Fish Aquat. Sci. 39:1459–1466.CrossRefGoogle Scholar
  32. Xun, L., Cambell, N.E.R., and Rudd, J.W.M., 1987. Measurements of specific rates of net methylmercury production in the water column and surface sediments of acidified and circumneutral lakes. Can. J. Fish Aquat. Sci. 44:750–757.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 1991

Authors and Affiliations

  • R. E. Hecky
    • 1
  • D. J. Ramsey
    • 1
    • 2
  • R. A. Bodaly
    • 1
  • N. E. Strange
    • 1
  1. 1.Department of Fisheries and OceansCentral and Arctic RegionWinnipegCanada
  2. 2.Agassiz North AssociatesWinnipegCanada

Personalised recommendations