Surplus Production Stock Reduction Analysis
SPSRA.Rd
A surplus production equivalent of DB-SRA that uses a demographically derived prior for intrinsic rate of increase (McAllister method, below)
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-class
with the TAC
slot populated with a numeric vector of length reps
Details
The TAC is calculated as: $$\textrm{TAC} = K D \frac{r}{2}$$ where \(K\) is estimated unfished biomass, \(D\) is depletion, and \(r\) is the estimated intrinsic rate of increase.
Like all SRA methods, this MP requires a time-series of catch extending from the beginning of exploitation.
Functions
SPSRA
: Base version. Requires an estimate of current depletionSPSRA_ML
: Variant that uses a mean-length mortality estimator to obtain a prior for current stock depletion.
Required Data
See Data-class
for information on the Data
object
SPSRA
: Cat, Dep, FMSY_M, L50, MaxAge, Mort, steep, vbK, vbLinf, vbt0, wla, wlb
SPSRA_ML
: CAL, Cat, Dep, FMSY_M, L50, Lbar, Lc, MaxAge, Mort, Year, steep, vbK, vbLinf, vbt0, wla, wlb
Rendered Equations
See Online Documentation for correctly rendered equations
References
McAllister, M.K., Pikitch, E.K., and Babcock, E.A. 2001. Using demographic methods to construct Bayesian priors for the intrinsic rate of increase in the Schaefer model and implications for stock rebuilding. Can. J. Fish. Aquat. Sci. 58: 1871-1890.
Examples
SPSRA(1, MSEtool::SimulatedData, plot=TRUE)
#> TAC (median)
#> 1106.57
SPSRA_ML(1, MSEtool::SimulatedData, plot=TRUE)
#> TAC (median)
#> 4005.328