Uniform grazing. = This is continuous grazing of phytoplankton. During a 24 h day, grazing rate varies very little. In this case, as well as in the case of non-uniform grazing, such factors as reproduction, mortality and grazing, influence the variations in the phytoplankton standing stock. This process is therefore described in the form of the same differential equation with the only difference that grazing rate qh is a constant value. = in this case, mortality of phytoplankton is proportional to the standing stock. Integrating the expression(11) we obtain =Knowing Ba, Bi, k and k, we may determine