1. Maximum Sustainable Yield

2. Sustainable Yield Sustainable Yield: Maximum Sustainable Yield:
The natural income that can be exploited each year without depleting the original stock or its potential for replenishment.
Maximum Sustainable Yield:
The highest amount that can be taken without depleting stock
How many fish, and of what size can be taken in any year?

3. Carrying Capacity Depends on 3 things for a species:
1) the species reproductive strategy
2) how long individuals live
3) resources available in habitat/ecosystem
Calculating Sustainable Yield
Each year new individuals enter a population, and some leave
If entering is greater than leaving, that amount can be harvested and is the maximum sustainable yield
SY = (annual growth and recruitment) – (annual death and emigration)

4. Harvesting the Maximum Sustainable Yield
Usually still leads to population decline because…
Predictions aren’t always accurate
Disease may strike or something else unaccounted for
Sex ratios may get thrown off

5. Optimal Sustainable Yield
Requires less effort
Maximizes the revenue to cost ratio
Much greater safety margin
May still impact population size
Fishing quotas usually set as a percentage of OSY per fleet per year.
It is a weight, not a number of fish