We present a model of a multispecies fishery, and we show the following. (i) Consumer
preferences for seafood diversity can trigger a sequential collapse of fish stocks under openaccess
fishery. (ii) The stronger the preferences are for diversity, the higher is the need for
coordinated multispecies regulation. (iii) Second-best optimal management of only one (or a
few) species is less strict than socially optimal management of the same species. (iv) Myopic
regulation of one species, ignoring spillovers to other species, can cause depletion of other
stocks that would not be depleted under open access.