The life of a lake is a dynamic journey of ecological succession. It begins in a clear, nutrient-poor oligotrophic state, progresses through a moderately productive mesotrophic phase to a highly productive eutrophic peak, and finally ends as a sediment-filled, low-productivity dystrophic bog.

While this represents a natural progression influenced by geology and climate, the pace and trajectory can be dramatically altered by human activity. Cultural eutrophication from pollution and land development can cause a lake to age prematurely, transforming it in decades rather than millennia. Therefore, understanding the processes that control primary productivity is not merely an academic exercise. It is the critical knowledge needed to manage our aquatic environments—to enhance their bounty where needed, and to protect their pristine clarity for the benefit of all mankind.