ABSTRACT
The chapter presents the applications of a set of equations describing the seasonal distribution of phytoplankton to the analysis of eutrophication problems in various locations. The general principle of conservation of mass is the basis which is used to formulate equations of the various constituents of importance in the analysis of the eutrophication problem, the essential element of which is the dynamic behavior of phytoplankton. The basic constituents of the analysis are the nutrients, phytoplankton and the zooplankton, for each of which an equation is developed. The analysis of phytoplankton growth in lake systems which are characterized by significant vertical stratification is the main purpose of this section. In natural waters there is a stepwise transformation from organic nitrogen to ammonia, nitrite and nitrate, yielding nutrients for phytoplankton growth.
