Sustainable Yield

How many fish can we take?

An interactive lesson with 6 steps, about 5 minutes: you predict, drag and solve, with instant feedback on every answer. It runs in your browser and needs JavaScript.

What you’ll learn

• Logistic growth is fastest at half the carrying capacity.
• Maximum sustainable yield $= rK/4$.
• Catches above it make stocks collapse, as happened to the Grand Banks cod.

Steps

1. Growth that peaks in the middle
2. Maximum sustainable yield
3. Too few to recover
4. Fish a fraction instead
5. The danger line
6. The Grand Banks