The article discusses the processes and patterns of oceanic nutrient limitation, focusing on how nutrient availability affects marine microbial activity and primary production. It highlights that nitrogen is a limiting factor in much of the surface low-latitude ocean, while iron limits productivity in regions with enhanced subsurface nutrient supply, such as the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins, and other micronutrients may also co-limit phytoplankton. The study emphasizes the importance of understanding nutrient stoichiometry and variability in nutrient supply and biological demand to predict the impacts of anthropogenic changes on oceanic nutrient biogeochemistry. It also discusses the role of nutrient limitation in the carbon cycle, noting that changes in nutrient cycles can influence atmospheric carbon dioxide concentrations and climate feedbacks. The article outlines the current understanding of nutrient limitation regimes in the modern ocean, identifying high-macronutrient, iron-limited systems and nitrogen-limited systems. It also addresses the potential for future changes in nutrient availability due to anthropogenic activities, including changes in nutrient demand, increased external nutrient inputs, and altered ocean circulation patterns. The study concludes that a comprehensive understanding of nutrient limitation is essential for predicting future changes in oceanic biogeochemistry and the carbon cycle.The article discusses the processes and patterns of oceanic nutrient limitation, focusing on how nutrient availability affects marine microbial activity and primary production. It highlights that nitrogen is a limiting factor in much of the surface low-latitude ocean, while iron limits productivity in regions with enhanced subsurface nutrient supply, such as the Southern Ocean and the eastern equatorial Pacific. Phosphorus, vitamins, and other micronutrients may also co-limit phytoplankton. The study emphasizes the importance of understanding nutrient stoichiometry and variability in nutrient supply and biological demand to predict the impacts of anthropogenic changes on oceanic nutrient biogeochemistry. It also discusses the role of nutrient limitation in the carbon cycle, noting that changes in nutrient cycles can influence atmospheric carbon dioxide concentrations and climate feedbacks. The article outlines the current understanding of nutrient limitation regimes in the modern ocean, identifying high-macronutrient, iron-limited systems and nitrogen-limited systems. It also addresses the potential for future changes in nutrient availability due to anthropogenic activities, including changes in nutrient demand, increased external nutrient inputs, and altered ocean circulation patterns. The study concludes that a comprehensive understanding of nutrient limitation is essential for predicting future changes in oceanic biogeochemistry and the carbon cycle.