Is aquaculture really an option?

This article analyzes the impact of the introduction of aquaculture on wild fish stocks and consumer utility, taking into account three key components: (1) the dependence of aquaculture on reduction fisheries for the feeding of the farmed species; (2) biological interactions between the wild edible species –the predator– and the wild feed species –the prey–; (3) consumer preferences for wild and farmed fish. Fisheries are in open access while the aquaculture sector is competitive. We show that when biological interactions are moderate, the introduction of aquaculture is beneficial in the long run; it improves consumer utility and alleviates the pressure on the edible fish stock. Results are deeply modified when biological interactions are strong: the stock of edible wild fish is reduced and the introduction of aquaculture may even cause a decrease in consumer utility. Finally, we explore the consequences of an improvement in aquaculture efficiency and of a sensitivity of consumer preferences to the farmed fish diet, in the case where biological interaction are absent.