Incremental Index Target MP - Effort-Based — ItargetE1 • DLMtool Functions

A management procedure that incrementally adjusts the fishing effort to reach a target CPUE / relative abundance index

Usage

ItargetE1(x, Data, reps = 100, plot = FALSE, yrsmth = 5, Imulti = 1.5)

ItargetE2(x, Data, reps = 100, plot = FALSE, yrsmth = 5, Imulti = 2)

ItargetE3(x, Data, reps = 100, plot = FALSE, yrsmth = 5, Imulti = 2.5)

ItargetE4(x, Data, reps = 100, plot = FALSE, yrsmth = 5, Imulti = 2.5)

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?
yrsmth: Years over which the average index is calculated.
Imulti: Parameter controlling how much larger target CPUE / index is compared with recent levels.

Value

An object of class Rec-class with the TAE slot(s) populated

Details

Four index/CPUE target MPs proposed by Geromont and Butterworth 2014.

The TAE is calculated as: If $I_\textrm{recent} \geq I_0$: $$\textrm{TAE}_y = 0.5 \textrm{TAE}_{y-1} \left[1+ \left( \frac{I_{\textrm{recent}} - I_0}{I_{\textrm{target}} - I_0} \right)\right]$$

else: $$\textrm{TAE}_y= 0.5 \textrm{TAE}_{y-1} \left( \frac{I_{\textrm{recent}}}{I_0}^2 \right)$$

where $I_0$ is $0.8 I_{\textrm{ave}}$ (the average index over the 2 x yrsmth years prior to the projection period), $I_\textrm{recent}$ is the average index over the past yrsmth years, and $I_\textrm{target}$ is Imulti times $I_{\textrm{ave}}$.

Functions

ItargetE1: The less precautionary TAE-based MP
ItargetE2: Increasing biologically precautionary TAE-based MP
ItargetE3: Increasing biologically precautionary TAE-based MP
ItargetE4: The most biologically precautionary TAE-based MP

Required Data

See Data-class for information on the Data object

ItargetE1: Ind, LHYear, MPeff, Year

Rendered Equations

See Online Documentation for correctly rendered equations

References

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. 72, 251-261. doi:10.1093/icesjms/fst232

Author

T. Carruthers

Examples

ItargetE1(1, MSEtool::Atlantic_mackerel, plot=TRUE)

#> Effort 
#>   0.85 
ItargetE2(1, MSEtool::Atlantic_mackerel, plot=TRUE)

#> Effort 
#>   0.85 
ItargetE3(1, MSEtool::Atlantic_mackerel, plot=TRUE)
#> Effort 
#>   0.85 
ItargetE4(1, MSEtool::Atlantic_mackerel, plot=TRUE)

#> Effort 
#>   0.85

Incremental Index Target MP - Effort-Based