The World Summit on Sustainable Development (Johannesburg, 2002)
encouraged the application of the ecosystem approach by 2010.
We propose a framework that deals jointly with i) ecosystem dynamics,
ii) conflicting issues of production and preservation and
iii) robustness with respect to dynamics uncertainties.
More specifically, we define robust viability kernels as initial
species biomasses such at least one appropriate harvesting
minimal production and preservation levels for all times, whatever the
uncertainties. We apply our approach to the anchovy--hake couple in the Peruvian
upwelling ecosystem. We comment on the management implications of
comparing robust viability kernels with and without uncertainties.