In this study, we consider the effects of impulsive copper contamination of the phytoplankton−zooplankton dynamics. We use the model on interactions between algae and Daphnia with deterministic and stochastic impulse copper contamination. In low environmental copper concentration (Cucst < 4.4μgL−1) our analysis show that, deterministic and stochastic pulses may promote the persistence of Daphnia and algae populations unlike the absence of pulses. We show that deterministic and stochastic pulses accelerate deficiency and toxicity processes, leading to the extinction of all populations, in high (Cucst > 28μgL−1) minimal of copper concentrations. In intermediate concentrations, deterministic and stochastic pulses may transform population dynamics in complex oscillations. Bifurcation diagram was computed to illustrate the different type observed dynamics in an environment with pulses of contamination. Depending on minimum copper concentration in the environment, this bifurcation diagram highlighted, the resilience or the regime shifts of the system in occurrence of pulse contamination. Our study may contribute to the prevalence of underestimation of extinction risk or population regime shifts from random fluctuations of pollution in real