Sustainable fisheries — AQA GCSE Biology
Test yourself on Sustainable fisheries with AQA GCSE practice questions.
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Sustainable fisheries explained
Fish stocks are populations of fish that are harvested for food.
Read the full explanation
They are declining because humans catch fish faster than the populations can reproduce. Modern fishing fleets use sonar, large nets and factory ships, so they can locate and remove huge numbers of fish in a short time. As the breeding population shrinks, fewer young fish are produced, so the stock falls further. This is unsustainable because the ocean cannot replace the fish as quickly as they are removed. For example, if a cod population is reduced below the level needed for successful spawning, recruitment of young cod falls and the stock may not recover for many years. Understanding this decline is the first step towards managing fisheries sustainably.
Your focus
- State that fish stocks in the oceans are declining.
- Explain why overfishing causes fish stocks to fall.
- Describe how a reduced breeding population leads to fewer young fish.
Sustainable fisheries exam tips
Marking Points
- State that fish stocks are populations of fish that are caught for food and that their numbers are falling.
- Explain that the rate of fishing exceeds the rate at which fish populations can reproduce.
- Describe how improved technology, such as sonar and large factory ships, increases the number of fish caught.
- Explain that a reduced breeding population produces fewer offspring, so the stock continues to decline.
- Recognise that the decline is unsustainable because fish are being removed faster than they can be replaced.
Examiner Tips
- 💡Use the phrase ‘caught faster than they can reproduce’ to make the cause of decline clear.
- 💡Link the decline to human demand for food and advances in fishing technology.
- 💡When describing a consequence, refer to the breeding population and the number of young fish produced.
Common Mistakes
- Thinking that fish stocks decline only because of pollution; the main cause is overfishing, where fish are caught faster than they can breed.
- Confusing a fish stock with the total number of all fish species in the ocean; a stock is a particular population that is fished.
- Assuming that fish populations can always recover quickly; if the breeding population becomes too small, recovery may take many years or may not happen.