EtargetLopt {DLMtool} R Documentation

## Effort Target Optimum Length

### Description

This MP adjusts effort limit based on the ratio of recent mean length (over last yrsmth years) and a target length defined as L_{\textrm{opt}}. Effort MP: adjust effort up/down if mean length above/below Ltarget

### Usage

EtargetLopt(x, Data, reps = 100, plot = FALSE, yrsmth = 3, buffer = 0.1)


### 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? yrsmth Number of years to calculate average length buffer Parameter controlling the fraction of calculated effor - acts as a precautionary buffer

### Details

The TAE is calculated as:

\textrm{TAE}_y = \textrm{TAE}_{y-1} ≤ft((1-\textrm{buffer}) (w + (1-w)r) \right)

where \textrm{buffer} is specified in argument buffer, w is fixed at 0.5, and:

r = \frac{L_{\textrm{recent}}}{L_{\textrm{opt}}}

where L_{\textrm{recent}}is mean length over last yrmsth years, and:

L_{\textrm{opt}} = \frac{L_∞ W_b}{\frac{M}{K} + W_b }

where L_∞ is von Bertalanffy asymptotic length, W_b is exponent of the length-weight relationship, M is natural mortality, and K is von Bertalanffy growth coefficient.#'

### Value

An object of class Rec-class with the TAE slot(s) populated

### Required Data

See Data-class for information on the Data object

EtargetLopt: ML, MPeff, Mort, vbK, vbLinf, wlb

### Rendered Equations

See Online Documentation for correctly rendered equations

HF Geromont

### Examples

EtargetLopt(1, MSEtool::SimulatedData, plot=TRUE)


[Package DLMtool version 6.0.2 Index]