A 250-year assessment of human impacts on Lake Superior: an updated paleolimnological perspective

A 250-year assessment of human impacts on Lake Superior: an updated paleolimnological perspective

2013-05

To understand environmental conditions in Lake Superior over the last two centuries, we conducted a paleolimnological study on two sediment cores collected in the eastern and western regions of the lake. We examined the diatom community assemblages, trace metals, sediment characteristics, and GIS-reconstructed human land use to evaluate the historical impacts of human activities. During European settlement and agricultural development, there is clear indication the diatom community reorganized due to nutrient enrichment. Trace metal profiles tracked a period of mining and ore processing which temporarily increased metal loads to the lake in the mid- to late-20th century. In recent decades, more oligotrophic diatom species were favored, suggesting nutrient decreases associated with remedial activities. The diatom community has reorganized to be dominated by Cyclotella species, providing evidence that water quality changes are being influenced by atmospheric nitrogen deposition and changes in the lake's physical and chemical processes associated with climate change.

Chraibi, Victoria Lindsay Shaw

University Of Minnesota: Water Resources Science

University of Minnesota

University of Minnesota (Minneapolis, Minnesota)

226

Surface Water
Water Monitoring & Assessment

Diatom
Land use
Nutrient Enrichment
Paleolimnology
Remediation
Water Quality

Lake Superior

2010-2019

Yes

http://hdl.handle.net/11299/157356

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Chraibi, Victoria Lindsay Shaw