NEMP funded a workshop at Charles Sturt University in Wagga Wagga in November 1997 to examine recent research into the limitations to phytoplankton growth that arise from nutrient limitation. In particular, there had been increasing evidence that nitrogen could in some circumstances be as important a limiting nutrient as phosphorus. If true, this finding could have important management implications. The main aim of the meeting was to review the current state of knowledge regarding the relative importance of different nutrients and variations in the light environment in controlling phytoplankton population dynamics in freshwaters. The outcome was to be a summary of current knowledge written in plain English for managers.