Mercury in Fish from Northeastern Minnesota Lakes: Historical Trends, Environmental Correlates, and Potential Sources
Swain EB and Helwig DD. 1989. Mercury in Fish from Northeastern Minnesota Lakes: Historical Trends, Environmental Correlates, and Potential Sources. Journal of the Minnesota Academy of Science. 55:p. 103-109
Discussion of recent research on mercury accumulation in fish. Indicates that mercury concentration in predators such as walleye and northern pike is statistically correlated with local water chemistry factors such as pH, dissolved organic matter, and alkalinity; and variation in mercury input among lakes is fairly small because the source of the mercury is the atmosphere, rather than geological sources. These two results can be reconciled by the observation that local environmental factors control the methylation of mercury, and that only methyl mercury accumulates in the food chain. Therefore, it is the local biological, chemical and physical factors that have produced the current variation in fish mercury concentration among lakes. Also notes that mercury concentrations in fish from low-alkalinity lakes have been increasing at a rate of 3-5 percent per year over the past 50 years. Comparable increases in sedimentary mercury accumulation rates (about 2 percent per year) have been observed.
- Type
- Journal Article
- Authors
- Swain, E; Helwig, D
- Units
- APIS , ARD , ISRO , SACN , VOYA
- Keywords
- Aquatic Sciences, ARD_Park-Air-Info_Collection, Contaminants, Deposition, Fish, Management, Mercury, Mercury (Hg), Plan, Pollution, St. Croix National Scenic Riverway Minnesota-Wisconsin, Toxics, Water Quality