Overfishing

Overfishing is a situation where one or more fish stocks are reduced below predefined levels of acceptance by fishing activities. More precise definitions are provided in biology and bioeconomics. Biological overfishing occurs when fishing mortality has reached a level where the stock biomass has negative marginal growth (slowing down biomass growth). Economic or bioeconomic overfishing in addition to the biological dynamics takes into consideration the cost of fishing and defines overfishing as a situation of negative marginal growth of resource rent. A more dynamic definition may also include a relevant discount rate and present value of flow of resource rent over all future catches.

Overfishing therefore may be sustainable, but in a non preferable way. Ultimately overfishing may however lead to depletion in cases of subsidised fisheries, low biological growth rates, critical biomass levels, etc.

Examples exist of the outcomes from overfishing in areas like the North Sea, and the Grand Banks on the east coast of North America. The result has been not only disastrous to fish stocks but also to the fishing communities relying on the harvest. Like forestry and hunting, fishery crisis is susceptible to economic interaction between ownership or stewardship and sustainability, or the tragedy of the commons.

The ability for nature to restore the fisheries is also dependent on whether the ecosystems are still in a state to allow fish numbers to build again. Dramatic changes in species composition may establish other equilibrium energy flows which involve other species compositions than before.

The "United Nations Convention on the Law of the Sea" treaty deals with aspects of overfishing in articles 61, 62, and 65.

• Article 61 requires all coastal states to ensure that the maintenance of living resources in their exclusive economic zones is not endangered by over-exploitation. The same article addresses the maintenance or restoration of populations of species above levels at which their reproduction may become seriously threatened.
• Article 62 provides that coastal states: "shall promote the objective of optimum utilization of the living resources in the exclusive economic zone without prejudice to Article 61"
• Article 65 provides generally for the rights of, inter alia, coastal states to prohibit, limit, or regulate the exploitation of marine mammals.

Solutions

Free market environmentalists propose privatization as a solution to overfishing. Daniel K. Benjamin, in Fisheries are Classic Example of the "Tragedy of the Commons", cites research by Grafton, Squires, and Fox to support the idea that privatization can solve the overfishing problem[1]:

According to recent research on the British Columbia halibut fishery, where the commons has been at least partly privatized, substantial ecological and economic benefits have resulted. There is less damage to fish stocks, the fishing is safer, and fewer resources are needed to achieve a given harvest.

See also

• catch and release
• Fisheries management
• World Ocean Day
• World Water Day

External links

• Seafood Watch from Monterey Bay Aquarium
• Overfishing
• Greenpeace
• National Geographic
• Fish Management
• Profiles of numerous websites on several aspects of fish and marine life
• Fishing Crisis
• Newfoundland Crisis
• The Starving Ocean
• Fisheries are Classic Example of the "Tragedy of the Commons"

See also: Overfishing, Bioeconomics, Biology, British Columbia, Catch and release, Depletion, Ecosystem, Exclusive economic zone, Fish stocks