Anoxia begets anoxia

Climate change has been shown to prolong water-column stratification, putting lakes at an increased risk of developing bottom-water anoxia. In this project, we will test if the development of bottom-water anoxia is followed by a feedback effect, accelerating hypolimnetic oxygen loss after the first occurrence of end-of-summer anoxia. We predict that this feedback will magnify the effects of climate change and land use on the development of anoxia in lakes around the world. Specifically, we hypothesize that this feedback effect is mediated by sediment nutrient release, with the consequence that its magnitude depends on lake bathymetry (i.e., hypolimnetic volume:sediment ratio). Understanding how the dynamics of hypolimnetic oxygen loss are coupled to trophic condition in a wide range of lakes will help to constrain their role as carbon sinks, and how this role may change in a changing climate.