Overfishing explained

Overfishing is a major global challenge that threatens ocean wildlife, livelihoods and seafood for future generations.

What is overfishing and why is it a problem?

When too many fish are caught and there are not enough adults to breed and sustain a healthy population, the stock is overfished.

In the early 90s, the impact of overfishing was increasingly a concern, culminating in the devastating collapse of Canada’s Grand Banks cod fishery in 1992. Over 35,000 fishers and plant workers from more than 400 coastal communities lost their jobs. 

This event was one of the catalysts for the creation of the MSC and the MSC Fisheries Standard - now the most globally recognised standard for sustainable, well-managed fisheries. 

What are the effects of overfishing?

When overfishing happens, populations of fish decline. The main effects of overfishing can be:

  • Fish stocks collapse and can take decades to recover threatening livelihoods, communities and food security
  • The price of fish can increase as supply falls and demand continues to increase
  • Fishing can become harder and less efficient 
  • When one fish is removed from an ecosystem it can lead to an ecosystem collapse
  • Protein demand shifts to other parts of the ocean or land placing pressure on other food systems

What is the main cause of overfishing?

When too many boats chase too few fish, there can be an overfishing situation. This can be due to short term profit or because of a lack of data and foresight. If we don't know how many fish there are and how much is being taken, it is very difficult to know how healthy a fish stock is. Illegal and unreported fishing is one reason for this.

The main causes of overfishing include:

  • Taking fish at a rate that is faster than they can reproduce
  • Not knowing how many fish have been taken such as illegal, unreported or unregulated fishing
  • Taking juvenile fish that haven't yet reproduced
  • Short-termism - being too focused on short term profits and not thinking about the future

Any kind of fishing can contribute to overfishing. Often overfishing is associated with commercial fishing but it can also be due to other forms of fishing such as recreational fishing.

How illegal fishing contributes to overfishing

Illegal, unregulated and unreported (IUU) fishing contributes to the problem of overfishing. It can take place without concern for the environment or the strict regulations on fishing quotas. 

Estimated to be worth US$10-23.5 billion annually, IUU fishing threatens the sustainability of fish populations, ecosystems and the livelihoods of those who fish legitimately.

The MSC program helps to drive out IUU fishing by disqualifying fisheries if they systematically engage in IUU fishing, or where IUU fishing by others is having a negative impact on the sustainability of the overall fishery. 

Patagonian toothfish (or Chilean seabass) is a good example of how fisheries are driving out IUU. For many years, uncontrolled IUU fishing was contributing to the decline of this high-value species.

Today, decisive action by six major toothfish fisheries – representing over 50% of world populations – has virtually eliminated IUU in the Southern Ocean. This has led to a significant recovery of the stocks and contributed to MSC certification of the fisheries. 

Find out more about toothfish


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Illegal fishing


Solutions to overfishing

Solutions to overfishing include:

The Marine Stewardship Council set standards for sustainable fishing and traceability within the seafood supply chain.

When you shop for seafood, look for the MSC blue fish tick label. This means seafood can be traced back to an MSC certified sustainable fishery.

MSC certified sustainable seafood

Find out more about practical solutions to tackle overfishing.

Your guide to sustainable seafood

Your guide to sustainable seafood

Find out where to buy, what to look for and the questions to ask.

Learn more

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Our approach

Our approach

Our approach means everyone can play a part in that future while enjoying seafood, not avoiding it.

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Our collective impact

Our collective impact

For more than 20 years fisheries, scientists, consumers and industry have been part of a collective effort to make sure our oceans are fished sustainably.

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What is sustainable fishing?

What is sustainable fishing?

Sustainable fishing means leaving enough fish in the ocean, respecting habitats and ensuring people who depend on fishing can maintain their livelihoods.

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