Paleolimnological data from the St. Louis River Estuary

Action items in the St. Louis River Remedial Action Plan (RAP) required data collection to support removing beneficial use impairments (BUI) to the Area of Concern. It was deemed important to understand remaining impacts in the St. Louis River and western Lake Superior, so a paleolimnological investigation provided an opportunity to reconstruct the algal and geochemical history for approximately the last 300 years. Most importantly, we identified historical temporal and spatial variations in water quality indicators related to eutrophication. Further, wild rice restoration work is part of the habitat restoration effort underway, so the paleolimnological work provided an additional opportunity to assess historical temporal and spatial variations of wild rice. Major goals were to reconstruct the biological (algal load and composition) and geochemical (organic and inorganic) chronology to identify historical temporal and spatial variations in the St. Louis River Estuary in order to better understand the natural and anthropogenic drivers related to beneficial use impairments for the St. Louis River Area of Concern.

This work was funded through a partnership between Minnesota Sea Grant (Research Project R/CE-05-14) and the Minnesota Pollution Control Agency (SWIFT Contract No. 0000000000000000000071178).