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Separate Biology · Paper 2 · Foundation + Higher · B7

Sustainable fisheries

Key ideas1 of 3

Keep enough breeding fish

A fishery is sustainable when harvesting can continue without driving the stock into long-term decline. Enough fish must survive to reproduce and replace losses. Catching more fish than the population can replace reduces future breeding stock. A large catch in one year does not prove that the stock is healthy. Assess stock surveys, the ages and sizes of fish, and changes over several years.

Net trial: A has 20 mm mesh, retains 70 of 100 juveniles and 80 of 100 mature fish. B has 60 mm mesh, retains 20 of 100 juveniles and 75 of 100 mature fish.

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Practice, downloads and sources

Daily 5 · Exam practice · Revision sheet ↓

Foundation + Higher · B7. Use alongside the shared B7 lessons.

AQA GCSE Biology 8461 · 4.7.5.3. Original notes, questions and diagrams. Models are simplified; teaching data are illustrative.