The intensification of lake anoxia poses significant risks to aquatic ecosystems and human water security. Prolonged oxygen depletion in lake hypolimnia can lead to biodiversity loss, increased greenhouse gas emissions, and higher costs for water treatment. Eutrophic lakes, which are nutrient-rich, are particularly vulnerable, with up to 90% projected to experience anoxic conditions by 2099 under severe warming scenarios. Even oligotrophic lakes, typically more resilient, are expected to see a rise in hypoxia and anoxia rates. These changes threaten cold-water fish species and disrupt ecological balance, with cascading effects on fisheries, water quality, and ecosystem services.