LstepCE1 | R Documentation |
A management procedure that incrementally adjusts the total allowable effort (TAE) according to the mean length of recent catches.
LstepCE1( x, Data, reps = 100, plot = FALSE, yrsmth = 5, stepsz = 0.05, llim = c(0.96, 0.98, 1.05) ) LstepCE2( x, Data, reps = 100, plot = FALSE, yrsmth = 5, stepsz = 0.1, llim = c(0.96, 0.98, 1.05) )
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? |
yrsmth |
Years over which to calculate trend in mean length. |
stepsz |
Parameter controlling the size of update increment in effort. |
llim |
A vector of length reference points that determine the conditions for increasing, maintaining or reducing the effort. |
The TAE is calculated as:
\textrm{TAE} = ≤ft\{\begin{array}{ll} \textrm{TAE}^* - 2 S\textrm{TAE}^* & \textrm{if } r < 0.96 \\ \textrm{TAE}^* - S \textrm{TAE}^* & \textrm{if } r < 0.98 \\ \textrm{TAE}^* & \textrm{if } > 1.058 \\ \end{array}\right.
where \textrm{TAE}^* is effort in the previous year, S is
step-size determined by stepsz
,
and r is the ratio of L_\textrm{recent} and L_\textrm{ave}
which are mean length over the most recent yrsmth
years and 2 x yrsmth
historical
years respectively.
The conditions are specified in the llim
argument to the function.
An object of class Rec-class
with the TAE slot(s) populated
LstepCE1
: The least biologically precautionary effort-based MP.
LstepCE2
: Step size is increased to 0.1
See Data-class
for information on the Data
object
LstepCE1
: LHYear, ML, MPeff, Year
See Online Documentation for correctly rendered equations
T. Carruthers
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
LstepCC1
LstepCE1(1, Data=MSEtool::SimulatedData, plot=TRUE) LstepCE2(1, Data=MSEtool::SimulatedData, plot=TRUE)
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.