DLMtool (version 5.3.1)

ITM: Index Target based on natural mortality rate

Description

An index target MP where the TAC is modified according to current index levels (mean index over last number of years determined by natural mortality (M)) relative to a target level.

Usage

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

Arguments

x

A position in a data-limited methods data object

Data

A data-limited methods 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

Required Data

See '>Data for information on the Data object

ITM: Ind, Iref, MPrec, Mort

Rendered Equations

See Online Documentation for correctly rendered equations

Details

The TAC is caluclated as: $$\textrm{TAC}_y = \textrm{TAC}_{y-1} \delta I$$ where \(\delta I\) is the ratio of the mean index over \(4\frac{1}{M}^{1/4}\) years to the reference index (Data@Iref).

The maximum fractional change in TAC is determined by \(mc\), defined as \(mc = \textrm{max}\left(\frac{5 + 25M}{100}, 0.2\right)\)

Examples

# NOT RUN {
ITM(1, Data=DLMtool::SimulatedData, plot=TRUE)
# }