Details

Autor(en) / Beteiligte

• Lewis, Abigail S. L.
• Lau, Maximilian P.
• Jane, Stephen F.
• Rose, Kevin C.
• Be'eri‐Shlevin, Yaron
• Burnet, Sarah H.
• Clayer, François
• Feuchtmayr, Heidrun
• Grossart, Hans‐Peter
• Howard, Dexter W.
• Mariash, Heather
• Delgado Martin, Jordi
• North, Rebecca L.
• Oleksy, Isabella
• Pilla, Rachel M.
• Smagula, Amy P.
• Sommaruga, Ruben
• Steiner, Sara E.
• Verburg, Piet
• Wain, Danielle
• Weyhenmeyer, Gesa A.
• Carey, Cayelan C.

Titel

Anoxia begets anoxia: A positive feedback to the deoxygenation of temperate lakes

Ist Teil von

• Global change biology, 2024-01, Vol.30 (1), p.e17046-n/a

Ort / Verlag

England: Blackwell Publishing Ltd

Erscheinungsjahr

2024

Link zum Volltext

Quelle

Wiley Blackwell Single Titles

Beschreibungen/Notizen

• Declining oxygen concentrations in the deep waters of lakes worldwide pose a pressing environmental and societal challenge. Existing theory suggests that low deep‐water dissolved oxygen (DO) concentrations could trigger a positive feedback through which anoxia (i.e., very low DO) during a given summer begets increasingly severe occurrences of anoxia in following summers. Specifically, anoxic conditions can promote nutrient release from sediments, thereby stimulating phytoplankton growth, and subsequent phytoplankton decomposition can fuel heterotrophic respiration, resulting in increased spatial extent and duration of anoxia. However, while the individual relationships in this feedback are well established, to our knowledge, there has not been a systematic analysis within or across lakes that simultaneously demonstrates all of the mechanisms necessary to produce a positive feedback that reinforces anoxia. Here, we compiled data from 656 widespread temperate lakes and reservoirs to analyze the proposed anoxia begets anoxia feedback. Lakes in the dataset span a broad range of surface area (1–126,909 ha), maximum depth (6–370 m), and morphometry, with a median time‐series duration of 30 years at each lake. Using linear mixed models, we found support for each of the positive feedback relationships between anoxia, phosphorus concentrations, chlorophyll a concentrations, and oxygen demand across the 656‐lake dataset. Likewise, we found further support for these relationships by analyzing time‐series data from individual lakes. Our results indicate that the strength of these feedback relationships may vary with lake‐specific characteristics: For example, we found that surface phosphorus concentrations were more positively associated with chlorophyll a in high‐phosphorus lakes, and oxygen demand had a stronger influence on the extent of anoxia in deep lakes. Taken together, these results support the existence of a positive feedback that could magnify the effects of climate change and other anthropogenic pressures driving the development of anoxia in lakes around the world. Declining oxygen concentrations in the deep waters of lakes worldwide pose pressing environmental and societal challenges. Existing theory suggests that deep‐water anoxia (very low dissolved oxygen) could drive a positive feedback, begetting increasingly severe occurrences of anoxia in following summers. Here, we analyzed the anoxia begets anoxia (ABA) feedback across 656 widespread temperate lakes. We found support for all relationships, with the strength of the feedback varying with lake‐specific characteristics (e.g., size, residence time). Ultimately, the ABA feedback could magnify the effects of climate change and other anthropogenic pressures driving the development of anoxia in lakes around the world.