Winter Oxygen Regimes in Clear and Turbid Shallow Lakes

Abstract

Dissolved oxygen levels in lake water control multiple physical and biological processes. Anoxia is defined as the absence of oxygen, though waters are often considered anoxic when oxygen concentrations fall below 1 g m −3 (Nürnberg, 1995). Anoxia can directly impact aquatic organisms as well as exert control over important chemical reactions. Low oxygen concentrations can lead to fish kills (Greenbank, 1945), with effects on fish community composition (Tonn & Magnuson, 1982) and the food web structure of lakes (Brothers et al., 2014; Carpenter et al., 2001). Anoxia also influences rates of decomposition and nutrient cycling (Burdige, 2007), due in part to the inhibition of aerobic metabolism and a shift to anaerobic metabolism (such as sulfate reduction, denitrification, and methanogenesis). Anaerobic metabolism can also release toxic compounds, such as methane and hydrogen sulfide, into the water column, further affecting some aquatic organisms. Oxygen depletion can occur due to the decomposition of excess organic matter, such as that provided from nutrient enrichment coupled with increased primary production (Gelda & Auer, 1996). This phenomenon is commonly observed in hypoxic/anoxic marine waters near river plumes (

Variability in Ice Cover Does Not Affect Annual Metabolism Estimates in a Small Eutrophic Reservoir

“…Contrary to expectation, we did not observe a shift in NEP across seasons. Unlike previous studies in which NEP shifted from positive to negative between summer and winter (Rabaey et al, 2021), leading to changes in annual…”

“…Journal of Geophysical Research: Biogeosciences 10.1029/2024JG008057 metabolism estimates (Brentrup et al, 2021), FCR exhibited similar NEP year-round (Figure 4c). This consistency across seasons may be potentially due to FCR's short ice cover duration or because it is a human-made reservoir and therefore may exhibit fundamentally different patterns of ecosystem functioning than the naturally-formed lakes examined by Brentrup et al (2021) and Rabaey et al (2021).…”

Whither Winter: The Altered Role of Winter for Freshwaters as the Climate Changes

“…Rabaey et al. (2021) observed similar DO dynamics in these systems in the open water seasons (spring, summer, and fall), while in winter under ice, there were greater oxygen depletion rates in the clear lakes, likely a consequence of degradation of the accumulated plant biomass without ingress from the atmosphere. Coupled with observations that clear lakes have lower N:P ratios than turbid lakes, likely due to increased denitrification (Ginger et al., 2017), it may be that winter provides some “memory” that is manifest throughout the year in these shallow lakes.…”

Under‐Ice Oxygen Depletion and Greenhouse Gas Supersaturation in North Temperate Urban Ponds

“…Microbial respiration under ice consumes autochthonous organic matter accumulated from the previous summer (Meding & Jackson, 2003;Powers et al, 2017). Previous studies have also shown that under-ice dissolved oxygen at the sediment-water interface is inversely related to the Journal of Geophysical Research: Biogeosciences 10.1029/2024JG008120 previous summer's maximum chl a concentration (Finlay et al, 2019;Terry et al, 2017) and macrophyte biomass (Meding & Jackson, 2003;Rabaey et al, 2021) in eutrophic, temperate, shallow lakes. The phytoplankton abundance and diversity can be similar between urban ponds and shallow lakes (Minelgaite et al, 2020) and floating macrophyte coverage can dominate small pond ecosystems (Gee et al, 1997).…”