Understanding groundwater-river exchanges is crucial for issues related to water quality and ecosystem health, as these exchanges partly determine river metabolism (related to respiration and primary production). River metabolism also depends on CO2 degassing to the atmosphere and biological responses, and it is especially important for small streams (Strahler order 1 to 3) where the groundwater-river interface can vary significantly in time and space. At the river reach scale, metabolism is (…)

Continuous and long-term measurement of the partial pressure of dissolved CO₂ (pCO₂) in aquatic environments—rivers, lakes, or groundwater—is essential to improve the quantification of carbon fluxes, particularly outgassing, but also ecosystem metabolism, as a complement to dissolved oxygen measurements.
Over the past decade, several developments have emerged, notably infrared sensors coupled with extraction systems—either passive, using gas measurement in a headspace behind a membrane, or (…)

Improving the understanding of the biogeochemical functioning of aquatic ecosystems aims to accurately quantify the spatial and temporal dynamics of ecosystem metabolism. This metabolism is closely linked to water flows and mixing from various sources, gas exchange with the atmosphere, and biological responses. In particular, dissolved gas tracers are used to identify where, when, and how different stages of water movement occur within hydrosystems. These dissolved gases originate from (…)