In the summer of 2022, a significant fish die-off occurred in the Oder River, affecting both German and Polish sections, resulting in hundreds of tons of dead fish and harm to other species like snails, worms, and mussels. Researchers at the Helmholtz Center for Environmental Research (UFZ) and EOMAP combined European Sentinel data with Planet SuperDove satellite imagery to conduct detailed water quality analysis, revealing a clear link between salt discharges and toxic algae proliferation.