Age-Composition Stock-Reduction Analysis

A stock reduction analysis (SRA) model is fitted to the age-composition from the last 3 years (or less if fewer data are available)

CompSRA(x, Data, reps = 100, plot = FALSE)

CompSRA4010(x, Data, reps = 100, plot = FALSE)

Arguments

x	A position in the data object
Data	A data object
reps	The number of stochastic samples of the MP recommendation(s)
plot	Logical. Show the plot?

Value

An object of class Rec with the TAC slot populated with a numeric vector of length reps

Details

A stock reduction analysis (SRA) model is fitted to the age-composition from the last 3 years (or less if fewer data are available) assuming a constant total mortality rate (Z) and used to estimate current stock depletion (D), \(F_\textrm{MSY}\), and stock abundance (A).

Abundance is estimated in the SRA. \(F_{\textrm{MSY}}\) is calculated assuming knife-edge vulnerability at the age of full selection.

The TAC is calculated as \(F_\textrm{MSY} A\). CompSRA4010 uses a 40-10 harvest control rule to reduce TAC at low biomass.

Functions

• CompSRA: TAC is FMSY x Abundance

• CompSRA4010: With a 40-10 control rule based on estimated depletion

Required Data

See Data for information on the Data object

CompSRA: CAA, Cat, L50, LFC, LFS, MaxAge, Mort, steep, vbK, vbLinf, vbt0, wla, wlb

CompSRA4010: CAA, Cat, L50, LFC, LFS, MaxAge, Mort, steep, vbK, vbLinf, vbt0, wla, wlb

Rendered Equations

See Online Documentation for correctly rendered equations

Examples

if (FALSE) {
CompSRA(1, DLMtool::SimulatedData, plot=TRUE)
}

CompSRA4010(1, DLMtool::SimulatedData, plot=TRUE)
#> TAC (median) 
#>      6733.58