The reduction in oxygen levels in rivers poses a severe threat to aquatic ecosystems. Fish and other aquatic species that rely on oxygen-rich environments are at risk of population declines or extinction in affected areas. Additionally, hypoxic conditions can disrupt local fisheries, impacting food security and livelihoods for communities dependent on these resources. The creation of 'dead zones' could also lead to long-term ecological imbalances, further endangering biodiversity and water quality.