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Article by Calvin R. Fremling regarding mayflies as river toxicity and water quality monitors. Fremling is credited as "professor in the Department of Biology at Winona State University, Winona, MN." Abstract: "Analysis of Hexagenia mayfly distribution patterns has proven to be a simple, inexpensive method of monitoring water quality in the Upper Mississippi River. Burrowing Hexagenia nymphs live at the mud-water interface intimately associated with organically enriched sediments that have a strong affinity for contaminants. By their presence or absence in silted habitats, they assess the synergistic effects of hypoxia, toxins, and other stresses throughout the year. Adults are large and easily collected, providing inexpensive water quality monitoring on a river so large that comprehensive chemical, physical, and biological analyses are not logistically feasible or affordable. Pollution abatement in metropolitan Minneapolis-St. Paul allowed a recurrence of Hexagenia in formerly denuded areas of Pool 2 and Lake Pepin during the early 1980s, but the drought of 1988 caused a population crash in both areas, demonstrating that the environment at the mud-water interface was intolerable to Hexagenia during low flow conditions." Article originally from Journal of the Minnesota Academy of Science, volume 55, number 1, 1989. Part of the Cal R. Fremling Collection.
Biologists; Mayflies; Pollution; Upper Mississippi River
Fremling, Cal R., "Hexagenia mayflies: biological monitors of water quality in the Upper Mississippi River" (1989). Cal Fremling Papers. 33.
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Winona County History Center-Armory Museum