This paper presents a simple dynamic model dealing with the management of a
marine renewable resource. But instead of studying the ecological and econ
omic interactions in terms of equilibrium or optimal control, we pay much a
ttention to the viability of the system or, in a symmetric way, to crisis s
ituations. These viability/crisis situations are defined by a set of econom
ic and biological state constraints. The analytical study focuses on the co
mpatibility between the state constraints and the controlled dynamics. Usin
g the mathematical concept of viability kernel, we reveal the situations an
d, if possible, management options to guarantee a perennial system. Going f
urther, we define 'overexploitation' indicators by the time of crisis funct
ion. In particular, we point out irreversible overexploitation configuratio
ns related to the resource extinction. (C) 2001 Elsevier Science B.V. All r
ights reserved.