Spatio-temporal variations in lateral and atmospheric carbon fluxes from the Danube Delta

The Danube Delta, a mosaic of ponds, channels, and wetlands, is a significant source of atmospheric carbon emissions. A two-year study found that the delta emits approximately 65 GgC yr⁻¹ of CO₂ and CH₄, with small channels contributing disproportionately to these emissions due to their high flux rates. While lakes can act as CO₂ sinks in summer, they are major emitters of methane (CH₄). The study also estimated that the delta exports about 160 ± 280 GgC yr⁻¹ of carbon to the Black Sea, a relatively small increase compared to the upstream river catchment but with a notably higher carbon yield per unit area. Researchers quantified these fluxes through monthly field campaigns at 19 sites, providing the first seasonally resolved estimates of freshwater carbon emissions in the delta.

Maier, M.-S., Teodoru, C. R., & Wehrli, B. (2021). Spatio-temporal variations in lateral and atmospheric carbon fluxes from the Danube Delta. Biogeosciences, 18(4), 1417–1437. https://doi.org/10.5194/bg-18-1417-2021