Hidden oxygen depletion mechanisms: are there implications for lake management strategies?

Session: Oxygen Cycling and Hypoxia: Processes, Impacts, and Management

Soren Brothers, Utah State University, [email protected]
Paul Sibley, University of Guelph, School of Environmental Sciences, [email protected]

Abstract

Lake water quality management strategies to avoid hypoxia are often designed with one prime mechanism in mind: namely, high nutrient loading leads to high phytoplankton productivity, which boosts sediment and/or hypolimnetic respiration rates to the point of hypoxia. While nutrient loading is an important driver of hypoxia, oxygen concentrations in lakes can be influenced by other direct and indirect factors, including changes in benthic algal primary production and dissolved organic carbon dynamics. We present research on the Laurentian Great Lakes, as well as findings from smaller eutrophic lakes, to examine whether such “hidden” alternative oxygen depletion mechanisms may be necessary for lake managers to consider in efforts to address hypoxia, especially in the context of accelerating climate change.