Paper 1 structured question: Management of the harvesting of marine species
Method
Method to Investigate Mesh Size Effect
1. Select three different mesh sizes: small, medium, and large. 2. Use identical fishing nets with these mesh sizes in the same fishing area. 3. Conduct fishing sessions of equal duration for each net. 4. Count and record the number of juvenile fish caught in each net. 5. Repeat the experiment three times for each mesh size to ensure reliability.
| Mesh Size | Number of Juvenile Fish Caught |
|---|---|
| Small | |
| Medium | |
| Large |
- a[1]
Identify the independent variable in this investigation.
Aim for approximately 1 distinct marking point.
- b[1]
Identify the dependent variable in this investigation.
Aim for approximately 1 distinct marking point.
- c[2]
Suggest one control variable that should be kept constant in this investigation and explain why.
Aim for approximately 2 distinct marking points.
- d[2]
Explain why repeating the experiment three times improves the reliability of the results.
Aim for approximately 2 distinct marking points.
