SCIENCE TALK Environmental Controls on the Conversion of Nutrients to Chlorophyll in Global Lakes

Prof. Roohollah Noori will present research on how anthropogenic inputs of nitrogen and phosphorus to lakes have increased worldwide, leading to higher phytoplankton chlorophyll concentrations at many sites, with implications for biodiversity and human use of lake resources. However, the conversion of nutrients to chlorophyll varies substantially among lakes, posing challenges for effective water quality management. Drawing on a rich global dataset, this Science Talk will explore how the relationship between chlorophyll-a (Chla), nitrogen, phosphorus, and inferred nutrient limitation is shaped by climate, catchment conditions, hydrology, and lake characteristics. The Science Talk will highlight how nutrient limitation differs across lake trophic states and depths, and examine the key environmental drivers influencing nutrient–chlorophyll dynamics, including water clarity, thermal region, elevation, depth, and watershed characteristics. By providing new insights into the environmental controls of global lake eutrophication, this Science Talk will contribute to a better understanding of the processes driving phytoplankton growth and support lake managers and policy-makers in mitigating widespread eutrophication.