Recruitment : increase of the fish in to the stock at the age a fish can be caught
Fish experience Mass Mortality at the early life stage. The magnitude will be less than 1/1000.
The S-R relationship is not clear and sometimes looks like no relationship between them.
S-R models are used for describing ideal relationship
Beverton and Holt Model
MSY will be calculated from S-R curve.
VBGC is often used for describing the fish growth
Weight is converted by the allometric equation.
Instantaneous rate of mortality is used
Total mortality Z is observed from age composition.
Usually Natural Mortality Mis estimated from Empirical Equations
Fishing mortality F is estimated as Z minus M