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Global Consequences of Overfishing

Overfishing is a global problem with many serious social, economic and environmental implications. Everyday, billions of people around the world rely on fish and seafood as a direct source of nutrition and a means of income. Now, more than ever before, our oceans are under pressure to meet the needs of growing populations in developing countries and a growing appetite for fish and seafood in developed nations.

Advances in fishing equipment and methods and increasingly large vessels have made it possible for commercial fishing operations to capture more fish, further from home, than ever before. This access is putting increasing pressure on fish stocks and also having an effect on the ability of smaller-scale fishing operations to make a living from fishing. Illegal, unreported and unregulated fishing is also a major contributor to declining fish stocks and marine habitat destruction.

The global consequences of overfishing have been the focus of much scrutiny in recent years by scientists, economists and policy makers and this important work continues. While there is much more to be learned about the long-term effects of overfishing, there is ample evidence to support taking a precautionary approach and to ensuring that entire ecosystems, and not just individual fish stocks, are considered when it comes to fisheries management.
Overfishing refers to:

  • A rate or level of fishing that is not sustainable, i.e. that hampers the rebuilding or recovery of a fish stock.

Economic and Social Effects

Despite having one of the most regulated fisheries in the world, Canada has not been immune to the effects of overfishing. The collapse of the Atlantic Canadian cod fishery in the 1990s is one of the most commonly cited examples in the world of overfishing and its economic, social and cultural implications.

Since the collapse of the cod, and resulting cod fishing moratorium, which has been in place since 1992, other fisheries, such as lobster and shrimp, have provided alternatives for some fish harvesters, however, many harvesters were forced to give up fishing—and a way of life passed down from generation to generation—altogether. Thousands of individuals have left the fishery for work in other trades or professions, and in many cases, other parts of the country.

Today, overfishing remains a threat to the social and economic welfare of many countries, but none more so than in developing island states. Fishing is not only an important facet of these economies, in many cases it is a central element in the traditional diet of its citizens. In many African and South Asian coastal nations, fish may account for as much as 50 per cent of protein in a typical diet. The decline of fish stocks in coastal waters as the result of overfishing and illegal fishing activities is making this important resource much less accessible for some of the world’s poorest citizens.

Environmental Effects

There is also growing evidence that the increased volume of fishing activity worldwide is having a very serious effect on the health of the oceans as a whole. When commercially valuable species are overexploited, other species and habitat that share the same ecosystem are affected.

For example, recent studies suggest that overfishing of large shark species has had a ripple effect in the shark’s food chain, increasing the number of species, such as rays, that are usual prey for large sharks, which result in declining stocks of smaller fish and shellfish favoured by these species.

In addition to harvesting large amounts of fish and seafood to sell, large-scale fishing operations catch and often unintentionally kill untargeted marine life, including juvenile fish, corals and other bottom-feeding organisms, sharks, whales, sea turtles, and birds. Killing these unintended species can have significant effects on marine ecosystems.
Based on new information about the dynamics of marine ecosystems, more and more countries and regional fisheries management organizations (RFMOs) are adopting an ecosystem-based approach to the management of fish stocks.