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Essay written by Calvin R. Fremling in a pamphlet of unrelated work including drawings and an essay about poetry. Summary: "...the meandering Mississippi of yesteryear has been transformed by man into a narrow, channelized, polluted, sinuous ditch from St. Louis to the Gulf of Mexico. Early channelization projects on the Upper Mississippi have been overshadowed by the impoundment projects of the 1930's. The navigation dams, from Minneapolis to St. Louis, have made the old free-flowing Mississippi into a series of large, well-fertilized, silted lakes, through which an appreciable current still flows. The main stream is punctuated by navigation structures which provide large surface areas for habitation by certain invertebrates. In areas where pollution is not severe, man has temporarily increased the carrying capacity of the Upper Mississippi River for burrowing mayflies, hydropsychid caddisflies and most species of river fish. He has lowered the carrying capacity of the river for clams. Extreme pollution in the Twin Cities area has transformed the river into an open sewer as far south as Hastings. Man's continued abuse of the watershed, the attendant elevation of the flood plain, and constriction of the flood plain will increase the severity of future floods." Reprinted from Mississippi River - Illinois Waterway 12 Foot Channel Study Phase 1 Report, U. S. Army Engineer Division. September 1972, Revised May 1973. 20 pages. Part of the Cal R. Fremling Collection.

Publication Date


Item Type





Winona, Minnesota


Biologists; Mississippi River; Mississippi River Ecology; Pollution


Special Collections-Library



Rights Management

Requests to reproduce this image must be granted by the Winona County Historical Society.

Contributing Institution

Winona County History Center

Master File Format


Fiscal Sponsor

This project has been financed in part with funds provided by the State of Minnesota from the Arts and Cultural Heritage Fund through the Minnesota Historical Society.

Scanning Responsibility

Northern Micrographics

Date Digital

2019-06-24 00:00

Metadata Creation Responsibility

Anna Gaffey

Unique Identifier


The Impact of Man on the Ecology of the Mississippi River



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