The paleolimnological records of Burntside and Shagawa Lakes in
northeastern Minnesota reveal that these two adjacent lakes have been
limnologically distinct for many years prior to the late 19th century
activities of white men that polluted Shagawa Lake. Although both lakes
occur within the same vegetation type and share much of their water, the
diatom stratigraphy of their bottom sediments indicates that Burntside
Lake was less productive in its natural state than Shagawa Lake. The
causes for this natural difference are not clearly known, but differences
in relative size of drainage area and in bedrock geology may be responsible.
Intensive white settlement around Shagawa Lake beginning in 1866
supplied nutrients that increased its productivity and finally supported
the massive blooms of blue-green algae that characterize culturally eutrophic
lakes. Burntside Lake was spared such intensive eutrophication, but its
diatom record shows that nutrients derived from shoreside recreational cabins
and related construction activity are increasing the lake's productivity.
The results of this study show that paleolimnological studies may provide
better comparative information for lake rehabilitation programs than do
biological and chemical analyses of contemporary unpolluted water bodies.
This report is contribution #155 of the Limnological Research Center,
University of Minnesota and was submitted in fulfillment of P.O. 04J1P0-0605
under the sponsorship of the U.S. Environmental Protection Agency.
Bradbury, J. P., & Waddington, J.C.B. (1978). A paleolimnological comparison of Burntside and Shagawa Lakes, Northeastern Minnesota (EPA-600/3-78-004). Corvallis, OR: Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency.
This report describes the results of a paleolimnological comparison of Burntside and Shagawa lakes in northeast Minnesota to determine the historic natural and cultural trophic changes in these lakes. Human settlement, especially mining and shoreline development, have impacted pollen, algael and diatom deposition in the lakes. The study emphasizes the sensitivity of diatom populations to environmental changes, especially from human settlement and activities, and how easily the delicate limnologic balance of a natural lake can be changed. The study documents the early history of Ely, Tower and Soudan due to mining and tourism shortly after the establishment of these towns. No mention is made of human influences prior to that time, nor of Native American settlements.
Note: this is a pdf of a typewritten paper and some pages are unclear and difficult to read.
US Environmental Protection Agency (EPA) report number EPA-600/3-78-004.
Bradbury, J. Platt; Waddington, Jean C B.
A Paleolimnological Comparison of Burntside and Shagawa Lakes, Northeastern Minnesota.
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