SPMSY {DLMtool} | R Documentation |
An MP that uses Martell and Froese (2012) method for estimating MSY to determine the OFL. Since their approach estimates stock trajectories based on catches and a rule for intrinsic rate of increase it also returns depletion. Given their surplus production model predicts K, r and depletion it is straight forward to calculate the OFL based on the Schaefer productivity curve.
SPMSY(x, Data, reps = 100, plot = FALSE)
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? |
The TAC is calculated as:
\textrm{TAC} = D K \frac{r}{2}
where D is depletion, K is unfished biomass, and r is intrinsic rate of increasase, all estimated internally by the method based on trends in the catch data and life-history information.
Requires the assumption that catch is proportional to abundance, and a catch time-series from the beginning of exploitation.
Occasionally the rule that limits r and K ranges does not allow r-K pairs to be found that lead to the depletion inferred by the catch trajectories. In this case this method widens the search.
An object of class Rec-class
with the TAC
slot populated with a numeric vector of length reps
See Data-class
for information on the Data
object
SPMSY
: Cat, L50, MaxAge, vbK, vbLinf, vbt0
See Online Documentation for correctly rendered equations
T. Carruthers
Martell, S. and Froese, R. 2012. A simple method for estimating MSY from catch and resilience. Fish and Fisheries. DOI: 10.1111/j.1467-2979.2012.00485.x
Other Surplus production MPs:
Fadapt()
,
Rcontrol()
,
SPSRA()
,
SPmod()
,
SPslope()
SPMSY(1, Data=MSEtool::SimulatedData, plot=TRUE)