Paired O 2 –CO 2 measurements provide emergent insights into aquatic ecosystem function

Scientific Significance Statement Metabolic stoichiometry predicts that dissolved oxygen (O 2 ) and carbon dioxide (CO 2 ) in aquatic ecosystems should covary inversely; however, field observations often diverge from theoretical expectations. Here, we propose a suite of metrics describing this O 2 and CO 2 decoupling and introduce a conceptual framework for interpreting these metrics within aquatic ecosystems. Within this framework, we interpret cross‐system patterns of high‐frequency O 2 and CO 2 measurements in 11 northern lakes and extract emergent insights into the metabolic behavior and the simultaneous roles of chemical and physical forcing in shaping ecosystem processes. This approach leverages the power of high‐frequency paired O 2 –CO 2 measurements, and yields a novel, integrative aquatic system typology which can also be applicable more broadly to streams and rivers, wetlands and marine systems.