Commercial boats catch one species of fish in a large lake. A manager tested two annual quotas, each limiting the mass of fish that could be caught. The same number of boats fished in each trial. The starting fish stock was 4000 tonnes in both trials. Each trial lasted three years, and there were no other management changes.
| Annual quota in tonnes | Mean annual mass caught in tonnes | Fish stock mass after three years in tonnes |
|---|---|---|
| 600 | 580 | 4600 |
| 1000 | 970 | 3200 |
Evaluate which annual quota should be used. Use information from the table and explain how the choice could affect the fishery in the future.
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.