DLMtool (version 5.2)

YPR: 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 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?

Fmin

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

Value

An object of class Rec 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 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, CAL_bins, Cat, LFS, MaxAge, Mort, vbK, vbLinf, vbt0

Rendered Equations

See Online Documentation for correctly rendered equations

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% of the slope at the origin, and A is an estimate of current abundance.

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). #'

References

Beverton and Holt. 1954.

Examples

# NOT RUN {
YPR(1, DLMtool::SimulatedData, plot=TRUE)
YPR_CC(1, DLMtool::SimulatedData, plot=TRUE)
YPR_ML(1, DLMtool::SimulatedData, plot=TRUE) 
# }