Dynamical systems analysis of a two level trophic food web in the Southern Oceans

A theoretical model developed by Stone describing a two level trophic system in the Ocean is analyzed, for the case in which there is unlimited supply of nutrients. We show that spontaneous oscillations in population numbers are possible, but they do not arise from a Hopf bifurcation. Seasonal forcing of the model is also investigated, and it is shown that resonances can occur, in addition to highly non-linear behaviour including high period oscillations, quasi-periodicity and chaos.