Surveys show that the number of mackerel in a fishing area has fallen. Boats are then allowed to catch fewer mackerel.
Why could this change help the mackerel stock increase?
The remaining mackerel breed at a faster rate than they did before
Young mackerel can escape through the nets and grow before being caught
More adult mackerel survive to breed, so more young mackerel are produced
Mackerel from nearby areas move in to take the place of those caught
87 exam-style questions on AQA GCSE Biology 7.5 Food production, covering 7.5.1 Factors affecting food security, 7.5.2 Farming techniques, 7.5.3 Sustainable fisheries, and 7.5.4 Role of biotechnology. Each one has a worked solution and a mark scheme showing where the marks go.