NOAA Arctic Report Card 2025 : Rusting Rivers

Terrestrial and aquatic ecosystems of the Arctic are undergoing rapid change due to the impacts of a changing climate and ecosystem disturbances. One climate-driven disturbance, permafrost thaw, is altering watershed hydrology and biogeochemical cycles (e.g., carbon cycling), with implications for coastal waters and marine ecosystems. Recent ground-based, aerial, and satellite observations from remote watersheds of northern Alaska indicate that hundreds of streams and rivers have shifted from pristine, clear water to an orange “rusting” condition, with many sites changing over the past decade (O’Donnell et al. 2024). This abrupt change appears to be an unanticipated consequence of permafrost thaw in the Arctic, and represents an emergent risk to water quality and aquatic life (Miner et al. 2021).