Sustainable resources: forests and fish stocksSpec 20.4.1, 20.4.2, 20.4.5, 20.4.6
In short
A sustainable resource is a resource which is produced as rapidly as it is removed from the environment so that it does not run out. Forests are conserved by education, protected areas, quotas and replanting. Fish stocks are conserved by education, closed seasons, protected areas, controlled net types and mesh size, quotas and monitoring of populations.
- Sustainable resource
- A resource which is produced as rapidly as it is removed from the environment so that it does not run out.
Some resources can be conserved and managed sustainably. Two examples are forests and fish stocks.
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanConserving forests
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels mean| Method | How it helps |
|---|---|
| Education | People learn why forests matter, so they use wood carefully and support protection |
| Protected areas | Laws stop trees being felled in national parks and reserves, so habitats and species are kept |
| Quotas | Limits on how many trees can be cut, so wood is removed no faster than it grows back |
| Replanting | New trees are planted to replace those felled, so forest cover is maintained |
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanConserving fish stocks
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels mean| Method | How it helps |
|---|---|
| Education | Fishers and consumers learn about overfishing and choose sustainable fish |
| Closed seasons | Fishing is banned during the breeding season, so fish can reproduce |
| Protected areas | Fishing is banned in some areas so populations can recover |
| Controlled net types and mesh size | Larger mesh lets young fish escape, so they can grow and breed; nets that catch other species by accident are banned |
| Quotas | Limits on the mass or number of fish that can be caught, so they are not removed faster than they reproduce |
| Monitoring | Fish populations are counted regularly so that quotas can be adjusted |
Supplement (what this means)
Supplement: only for the Extended papers (2 and 4). Core students can skip it. What the labels meanExam tip:
Say how each method helps: 'larger mesh size lets young fish escape so they can breed later', not just 'larger mesh size'.
Written and checked against the Cambridge IGCSE Biology (0610) specification · Updated October 2026