Overfishing is the removal of a species of fish from a body of water at a rate greater than that the species can replenish its population naturally, resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any size, such as ponds, wetlands, rivers, lakes, or oceans, and can result in resource depletion, reduced biological growth rates, and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself.
Overfishing is a global problem that can impact entire ecosystems. It can change the size of fish remaining, as well as how they reproduce and the speed at which they mature. When too many fish are taken out of the ocean, it creates an imbalance that can erode the food web and lead to a loss of biodiversity. Overfishing is closely tied to bycatch, which is the capture of unwanted sea life while fishing for a different species. This, too, is a serious marine threat that causes the needless loss of billions of fish, along with hundreds of thousands of sea turtles and cetaceans.
Overfishing can also have significant economic impacts. Billions of people rely on fish for protein, and fishing is the principal livelihood for millions of people around the world. Overfishing can lead to the collapse of fish stocks, which can be devastating for fishing communities that rely on the harvest.
Factors that drive overfishing include rising consumption, climate change, and illegal, unreported, and unregulated (IUU) fishing. Rising consumption of aquatic foods (farmed and wild) is rising twice as fast as the global population. Increases in ocean temperatures change the migratory routes of fish stocks, causing them to move away from traditional fishing grounds. Overfishing occurs when fisheries continue to catch at the same level even though some of their target species have moved to new grounds. Illegal, unreported, and unregulated fishing involves catching fish without abiding by governmental and international regulations, for example, in protected zones, or not reporting part of the catches.
To prevent overfishing, it is important to manage fisheries sustainably. This can involve setting catch limits, reducing bycatch, and implementing fishing gear modifications that reduce the impact on non-target species. It is also important to reduce subsidies provided to the fishing industry to offset the costs of doing business, which can lead to overcapacity of fishing vessels and skewing of production costs so that fishing operations continue when they would otherwise not make economic sense.
