`LstepCE1.Rd`

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. |

An object of class `Rec-class`

with the TAE slot(s) populated

The TAE is calculated as:
$$\textrm{TAE} =
\left\{\begin{array}{ll}
\textrm{TAE}^* - 2 S\textrm{TAE}^* & \textrm{if } r < 0.96 \\
\textrm{TAE}^* - S \textrm{TAE}^* & \textrm{if } r < 0.98 \\
\textrm{TAE}^* & \textrm{if } > 1.058 \\
\end{array}\right.
$$
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.

`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

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

T. Carruthers

#> Effort #> 1#> Effort #> 1