Paleolimnology of the Lake of the Woods southern basin: continued water quality degradation despite lower nutrient influx

ABSTRACTReavie ED, Edlund MB, Andresen NA, Engstrom DR, Leavitt PR, Schottler S, Cai M. 2017. Paleolimnology of the Lake of the Woods southern basin: Continued water quality degradation despite lower nutrient influx. Lake Reserv Manage. 00:00–00.Despite decades of reduced nutrient inputs, Lake of the Woods, a large, shallow boreal lake on the US-Canadian border, shows little evidence of water quality improvements in the pelagic system. Here we analyzed sediments from 6 sites in the southern basin for diverse biogeochemical (loss-on-ignition, biogenic silica, pigments) and microfossil (diatoms, chrysophytes) remains to reconstruct the environmental history of the lake. Our objectives were to quantify the magnitude and direction of historical trophic change and evaluate reasons for an apparent lack of basin recovery following documented nutrient diversion. Evidence came from fossil indicator profiles and comparisons of these long-term trends with historical land use and monitoring data. Results indicate maj...