Document Type


Publication Date



Hexagenia; Water quality


ABSTRACT-Analysis of Hexageniamayfiy 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 mudwater 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 mudwater interface was intolerable to Hexagenia during low flow conditions.

First Page


Last Page


Primo Type




To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.