Abstract: The results I will present come from joint works and work-in-progress with Silvia Faggian (University of Venice) and Giuseppe Freni (University of Naples "Parthenope").

After a review of the literature on strategic competition in theoretical spatial distributed natural resources ("fishes") models, a class of linear models on networks will be discussed and some general ecological questions will be rephrased in this framework. Two specific questions will be addressed then:

(i) when, in a two-country context, can the creation of reserves and the introduction of property rights be effective in terms of reduction of overexploitation of the resource and aggregate welfare?
(ii) where, in a more general context, can be more efficient to build a reserve?