How overfishing can improve fishery production

Overfishing is generally believed to drive collapses of ecosystems and fisheries. However, overfishing can unintentionally cultivate ecosystems to improve the productivity of some species, even while ecosystems are degraded.... [ view full abstract ]

Overfishing is generally believed to drive collapses of ecosystems and fisheries. However, overfishing can unintentionally cultivate ecosystems to improve the productivity of some species, even while ecosystems are degraded. We reviewed known cases of unintended cultivation to identify common causes and consequences for fisheries. We found two common ecological drivers of cultivation: trophic release of prey species by overfishing of predators, and habitat change. Several ecological, economic and social conditions have to align for unintended cultivation to occur. These conditions include, strong top-down control of predators by prey, high value prey species and the capacity of fisheries to switch target species. In the short-term, restoration of ecosystems toward their ‘pristine’ or historical state may threaten fisheries that depend on high value ‘cultivated’ species. Thus, unintended cultivation may create conflicts between fisheries and efforts to restore ecosystems toward their past states. However, in the long-term, restoring ecosystems may benefit fisheries by providing diverse and stable harvest opportunities. Greater appreciation and identification of cultivation effects is necessary for ecosystem management to find compatible goals for fisheries and conservation.