YPR {DLMtool}

Yield Per Recruit analysis to get FMSY proxy F01

Description

A simple yield per recruit approximation to FMSY (F01) which is the position of the ascending YPR curve for which dYPR/dF = 0.1(dYPR/d0)

Usage

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

YPR_CC(x, Data, reps = 100, plot = FALSE, Fmin = 0.005)

YPR_ML(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?

Fmin

The minimum fishing mortality rate inferred from the catch-curve analysis

Details

The TAC is calculated as:

\textrm{TAC} = F_{0.1} A

where F_{0.1} is the fishing mortality (F) where the slope of the yield-per-recruit (YPR) curve is 10\

The YPR curve is calculated using an equilibrium age-structured model with life-history and selectivity parameters sampled from the Data object.

The variants of the YPR MP differ in the method to estimate current abundance (see Functions section below). #'

Value

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

Functions

• YPR: Requires an external estimate of abundance.

• YPR_CC: A catch-curve analysis is used to determine recent Z which given M (Mort) gives F and thus abundance = Ct/(1-exp(-F))

• YPR_ML: A mean-length estimate of recent Z is used to infer current abundance.

Required Data

See Data-class for information on the Data object

YPR: Abun, LFS, MaxAge, vbK, vbLinf, vbt0

YPR_CC: CAA, Cat, LFS, MaxAge, vbK, vbLinf, vbt0

YPR_ML: CAL, Cat, LFS, Lbar, Lc, MaxAge, Mort, vbK, vbLinf, vbt0

Rendered Equations

See Online Documentation for correctly rendered equations

Note

Based on the code of Meaghan Bryan

Author(s)

Meaghan Bryan and Tom Carruthers

References

Beverton and Holt. 1954.

Examples

YPR(1, MSEtool::SimulatedData, plot=TRUE)
YPR_CC(1, MSEtool::SimulatedData, plot=TRUE)
YPR_ML(1, MSEtool::SimulatedData, plot=TRUE)