Three identical boats tested nets with different mesh sizes. Each boat fished for 10 hours at the same time in nearby parts of the same area. The only planned difference was the mesh size.
| Mesh size / mm | Mass of sardines caught / kg | Number of sardines shorter than 20 cm |
|---|---|---|
| 60 | 265 | 142 |
| 80 | 198 | 58 |
| 100 | 126 | 11 |
Give one conclusion about the effect of mesh size on the catch.
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.