Summary
1. Mathematical descriptions of uniform and non- uniform phytoplankton grazing by zooplankton are presented and equations for calculating the dependence of phytoplankton production on rate and rhythm of elimination are deduced.
2. of greatest interest is non-uniform phytoplankton grazing, which is reflected in a sinusoidal curve and is usually found in a baththyplankton ecosystem with migratory consumers
3. Phytoplankton production depends upon the time of grazing; the nearer towards nightfall grazing occurs, the higher is the phytoplankton production.
4. In order to be able to calculate the phytoplankton production and the amount of food consumed under conditions of non-uniform sinusoidal grazing,