  Some monospecies age class models, as well as specific multi-species models
(with so-called technical interactions), exhibit useful monotonicity
properties. This paper deals with discrete time monotone bioeconomics dynamics
in the presence of state and control constraints. In practice, these latter
"acceptable configurations" represent production and preservation requirements
to be satisfied for all time, and they also possess monotonicity properties. A
state $x$ is said to belong to the viability kernel if there exists a
trajectory, of states and controls, starting from $x$ and satisfying the
constraints. Under monotonicity assumptions, we present upper and lower
estimates of the viability kernel. This helps delineating domains where a
viable management is possible. Numerical examples, in the context of fisheries
management, for the Chilean sea bass (\emph{Dissostichus eleginoides}) and
Alfonsino (\emph{Beryx splendens}) are given.
