LtargetE1.Rd
A management procedure that incrementally adjusts the TAE to reach a target mean length in catches.
LtargetE1(x, Data, reps = 100, plot = FALSE, yrsmth = 5, xL = 1.05)
LtargetE4(x, Data, reps = 100, plot = FALSE, yrsmth = 5, xL = 1.15)
A position in the data object
A data object
The number of stochastic samples of the MP recommendation(s)
Logical. Show the plot?
Years over which to calculate mean length
Parameter controlling the magnitude of the target mean length of catches relative to average length in catches.
An object of class Rec-class
with the TAE slot(s) populated
Four target length MPs proposed by Geromont and Butterworth 2014. Tested by Carruthers et al. 2015.
The TAE is calculated as:
If \(L_\textrm{recent} \geq L_0\): $$\textrm{TAE} = 0.5 \textrm{TAE}^* \left[1+\left(\frac{L_\textrm{recent}-L_0}{L_\textrm{target}-L_0}\right)\right] $$
else: $$\textrm{TAE} = 0.5 \textrm{TAE}^* \left[\frac{L_\textrm{recent}}{L_0}^2\right] $$
where \(\textrm{TAE}^*\) is the effort in the previous year,
\(L_\textrm{recent}\) is mean length in last yrmsth
years, \(L_0\) is (except for L95target
) 0.9 average catch in the last
2 x yrsmth
historical (pre-projection years) (\(L_\textrm{ave}\)), and \(L_\textrm{target}\) is
(except for L95target
) xL
\(L_\textrm{ave}\).
LtargetE1
: The least biologically precautionary TAE-based MP.
LtargetE4
: The xL
argument is increased to 1.15.
See Online Documentation for correctly rendered equations
Carruthers et al. 2015. Performance evaluation of simple management procedures. ICES J. Mar Sci. 73, 464-482.
Geromont, H.F., Butterworth, D.S. 2014. Generic management procedures for data-poor fisheries; forecasting with few data. ICES J. Mar. Sci. doi:10.1093/icesjms/fst232
Other Length target MPs:
Lratio_BHI()
,
Ltarget1()
LtargetE1(1, Data=MSEtool::SimulatedData, plot=TRUE)
#> Effort
#> 0.85
LtargetE4(1, Data=MSEtool::SimulatedData, plot=TRUE)
#> Effort
#> 0.85