The article discusses the dynamics and distribution of natural and human-caused hypoxia in marine ecosystems. Hypoxia, defined as water masses with dissolved oxygen levels below 2 mg/L or 30% saturation, can form naturally due to processes like photosynthetic carbon production and microbial respiration, especially in areas with extended water residence times, minimal ventilation, and high carbon production. However, human activities, particularly increased nutrient loading, have accelerated hypoxia in many coastal areas, leading to the formation of "dead zones." These zones are more prevalent in regions with high population density and nutrient export from watersheds. Global climate change further complicates the situation by enhancing stratification and increasing freshwater discharge, exacerbating hypoxia. The article highlights the need for long-term, broad-scale efforts to reduce nutrient loads to mitigate the impacts of hypoxia on ecosystems and fisheries.The article discusses the dynamics and distribution of natural and human-caused hypoxia in marine ecosystems. Hypoxia, defined as water masses with dissolved oxygen levels below 2 mg/L or 30% saturation, can form naturally due to processes like photosynthetic carbon production and microbial respiration, especially in areas with extended water residence times, minimal ventilation, and high carbon production. However, human activities, particularly increased nutrient loading, have accelerated hypoxia in many coastal areas, leading to the formation of "dead zones." These zones are more prevalent in regions with high population density and nutrient export from watersheds. Global climate change further complicates the situation by enhancing stratification and increasing freshwater discharge, exacerbating hypoxia. The article highlights the need for long-term, broad-scale efforts to reduce nutrient loads to mitigate the impacts of hypoxia on ecosystems and fisheries.