Harvest Last Emailed Lecture

Question 1

Difference between Maximum sustained yield and optimum yield

Answer 1

1. Economics favor taking less than MSY.
2. Do we really know what is going on with B, D, K, DD, Vital rights, inherently lots of variables to take into account.

Optimum yield is more practical because MSY is an elusive concept

Question 2

Ratchet effect

Answer 2

continual overexploitation of a population. Continual ratcheting down on population until is collapses

Question 3

Examples of ratchet effect

Answer 3

Canadian atlantic cod and USA King crab

Question 4

Ludwig’s ratchet

Answer 4

for a fluctuating resource, continuing economic investment and ecological optimism fuel positive feedback that ratchet ups harvest rate to unsustainable levels and causes the eventual collapse.

Question 5

How to avoid harvest collapse?

Answer 5

2 strategies:

1. Implement management that minimizes chance of extinction
2. No-take zones. Take regulate outside zone but no take acts as a safe zone

Question 6

ways to manage stocks (3)

Answer 6

unchanging quota, constant removal rate, and threshold population