Discretion rather than rules in multiple-species fisheries

This paper evaluates the bioeconomic performance of individual fishing quota (IFQ) regulations in multiple-species fisheries. In our model, a manager chooses the aggregate quotas under uncertainty over the true stock abundances of two jointly-harvested fish species. Fishers conduct harvest operations under full knowledge of the species-specific productivities of fishing gear. We derive the profit maximizing fishing mortality and economic rent outcomes implemented by fishers under various regulatory designs. We compare bioeconomic performance of an IFQ regulation with discretion over the mix of harvested species against an IFQ regulation that bans at-sea discarding. Both regulations eliminate discards. Discretion allows closer alignment between fisher implemented outcomes and those that maximize long term expected fishery value. Incorporating discretion into regulatory designs provides new prospects for improving fisheries management.