Bifurcation Analysis of a Marine Food Chain

Bifurcation theory and dynamical systems
techniques were used to analyze the joint effect of
contaminants and nutrient loading on population
dynamics of marine food chains. Contaminant
toxicity is assumed to alter mortality of some species
with a sigmoidal dose-response relationship. A
generic effect of pollutants is to delay transitions to
complex dynamical states towards higher nutrient
load values, but more counterintuitive consequences
arising from indirect effects are described.
In particular, the top predator seems to be the
species more affected by pollutants, even when
contaminant is toxic only to lower trophic levels