Sustainable Fisheries (AQA GCSE Biology): Revision Notes

7.5.3 Sustainable Fisheries

Key Issues:

• Overfishing: When fish are harvested at a rate that exceeds the ability of populations to replenish, it leads to a decline in fish numbers, threatening the survival of some species.
• Population Thresholds: To prevent species from becoming endangered or extinct, fish populations must be maintained above a certain level. This ensures there are enough mature individuals to continue breeding and sustain the population.

Measures for Sustainable Fishing:

1. Net Size Regulations:

• Larger Net Sizes: Regulations require the use of larger mesh sizes in fishing nets. This allows smaller, juvenile fish to escape, giving them the chance to grow to maturity and reproduce, helping to sustain fish populations.

2. Fishing Quotas:

• Catch Limits: Fishing quotas are set to restrict the amount of a specific species that can be caught in a particular area and time period. These quotas are designed to prevent overfishing by ensuring that only a sustainable number of fish are removed from the ocean.