Chapter 5 Management Procedures

The purpose of an MSE is to compare the performance of alternative management approaches, or Management Procedures to identify the method that is most likely to meet the management objectives for the fishery.

5.1 What is a Management Procedure?

In essence, a Management Procedure is simply a set of rules which define how a fishery will be managed. These rules can range from simple harvest policies to more complex arrangements.

For example, a simple Management Procedure may be a constant catch policy, where the annual total allowable catch (TAC) is set a some fixed value. Alternatively, a more complex Management Procedure may involve multiple data sources, with rules that increase or reduce the TAC in response to trends in one or several indicators.

Management Procedures can differ in data requirements and complexity. However, all Management Procedures have one thing in common. They take fishery information and return a management recommendation.

To be included in an MSE, a Management Procedure must be reproducible and able to be coded in a set of instructions. While fisheries are sometimes managed by expert judgment, it is difficult to reproduce the subjective decision-making process in a computer simulation and include such methods in an MSE.

5.2 Available Management Procedures

All management procedures in DLMtool are objects (actually functions in this case) of class MP. There are a number of MPs built into DLMtool. The avail function can be used to provide a list of MPs that can be included in the MSE:

avail('MP')
##   [1] "AvC"          "AvC_MLL"      "BK"           "BK_CC"        "BK_ML"        "CC1"          "CC2"         
##   [8] "CC3"          "CC4"          "CC5"          "CompSRA"      "CompSRA4010"  "CurC"         "curE"        
##  [15] "curE75"       "DAAC"         "DBSRA"        "DBSRA_40"     "DBSRA4010"    "DCAC"         "DCAC_40"     
##  [22] "DCAC_ML"      "DCAC4010"     "DCACs"        "DD"           "DD4010"       "DDe"          "DDe75"       
##  [29] "DDes"         "DepF"         "DTe40"        "DTe50"        "DynF"         "EtargetLopt"  "Fadapt"      
##  [36] "Fdem"         "Fdem_CC"      "Fdem_ML"      "FMSYref"      "FMSYref50"    "FMSYref75"    "Fratio"      
##  [43] "Fratio_CC"    "Fratio_ML"    "Fratio4010"   "GB_CC"        "GB_slope"     "GB_target"    "Gcontrol"    
##  [50] "HDAAC"        "ICI"          "ICI2"         "Iratio"       "Islope1"      "Islope2"      "Islope3"     
##  [57] "Islope4"      "IT10"         "IT5"          "Itarget1"     "Itarget1_MPA" "Itarget2"     "Itarget3"    
##  [64] "Itarget4"     "ItargetE1"    "ItargetE2"    "ItargetE3"    "ItargetE4"    "ITe10"        "ITe5"        
##  [71] "ITM"          "L95target"    "LBSPR"        "LBSPR_MLL"    "Lratio_BHI"   "Lratio_BHI2"  "Lratio_BHI3" 
##  [78] "LstepCC1"     "LstepCC2"     "LstepCC3"     "LstepCC4"     "LstepCE1"     "LstepCE2"     "Ltarget1"    
##  [85] "Ltarget2"     "Ltarget3"     "Ltarget4"     "LtargetE1"    "LtargetE4"    "matlenlim"    "matlenlim2"  
##  [92] "MCD"          "MCD4010"      "minlenLopt1"  "MRnoreal"     "MRreal"       "NFref"        "Rcontrol"    
##  [99] "Rcontrol2"    "SBT1"         "SBT2"         "slotlim"      "SPmod"        "SPMSY"        "SPslope"     
## [106] "SPSRA"        "SPSRA_ML"     "YPR"          "YPR_CC"       "YPR_ML"       "avgMP"        "TCPUE"       
## [113] "TCPUE_e"      "THC"

As you can see, there are 114 MPs built into the DLMtool.

DLMtool is extensible and it is relatively straightforward to develop your own MPs and include them in the MSE. This is covered in Developing Custom Management Procedures.

5.3 Types of Management Procedure

In previous versions of DLMtool, the MPs were divided into two classes: Output controls which returned a total allowable catch (TAC) and Input controls which allow regulation of fishing effort, size selectivity, or spatial area.

Since DLMtool V5.1 it is possible to include MPs that provide a combination of input and output controls.

All MPs in DLMtool are now class MP, but the MPs are divided into four types: Input which allow regulation offishing effort, size selectivity, or spatial area but not a TAC, Output which return only a TAC recommendation, Mixed which return a combination of one or several input controls and a TAC, and Reference which are MPs that have been designed to be used as reference management procedures (e.g FMSYref which uses perfect information of FMSY and abundance).

The MPtype function can be used to display the type for a particular MP, for example:

MPtype("DCAC")
##     MP   Type Recs
## 1 DCAC Output  TAC

This tells us that DCAC is an Output control MP and returns a management recommendation in the form of a total allowable catch limit (TAC).

Here we list all available MPs:

MPtype(avail('MP'))
##               MP      Type         Recs
## 1           curE     Input          TAE
## 2         curE75     Input          TAE
## 3            DDe     Input          TAE
## 4          DDe75     Input          TAE
## 5           DDes     Input          TAE
## 6          DTe40     Input          TAE
## 7          DTe50     Input          TAE
## 8    EtargetLopt     Input          TAE
## 9      ItargetE1     Input          TAE
## 10     ItargetE2     Input          TAE
## 11     ItargetE3     Input          TAE
## 12     ItargetE4     Input          TAE
## 13         ITe10     Input          TAE
## 14          ITe5     Input          TAE
## 15         LBSPR     Input          TAE
## 16     LBSPR_MLL     Input           SL
## 17      LstepCE1     Input          TAE
## 18      LstepCE2     Input          TAE
## 19     LtargetE1     Input          TAE
## 20     LtargetE4     Input          TAE
## 21     matlenlim     Input           SL
## 22    matlenlim2     Input           SL
## 23   minlenLopt1     Input           SL
## 24      MRnoreal     Input      Spatial
## 25        MRreal     Input      Spatial
## 26       slotlim     Input           SL
## 27       TCPUE_e     Input          TAE
## 28       AvC_MLL     Mixed      TAC, SL
## 29  Itarget1_MPA     Mixed TAC, Spatial
## 30           AvC    Output          TAC
## 31            BK    Output          TAC
## 32         BK_CC    Output          TAC
## 33         BK_ML    Output          TAC
## 34           CC1    Output          TAC
## 35           CC2    Output          TAC
## 36           CC3    Output          TAC
## 37           CC4    Output          TAC
## 38           CC5    Output          TAC
## 39       CompSRA    Output          TAC
## 40   CompSRA4010    Output          TAC
## 41          CurC    Output          TAC
## 42          DAAC    Output          TAC
## 43         DBSRA    Output          TAC
## 44      DBSRA_40    Output          TAC
## 45     DBSRA4010    Output          TAC
## 46          DCAC    Output          TAC
## 47       DCAC_40    Output          TAC
## 48       DCAC_ML    Output          TAC
## 49      DCAC4010    Output          TAC
## 50         DCACs    Output          TAC
## 51            DD    Output          TAC
## 52        DD4010    Output          TAC
## 53          DepF    Output          TAC
## 54          DynF    Output          TAC
## 55        Fadapt    Output          TAC
## 56          Fdem    Output          TAC
## 57       Fdem_CC    Output          TAC
## 58       Fdem_ML    Output          TAC
## 59        Fratio    Output          TAC
## 60     Fratio_CC    Output          TAC
## 61     Fratio_ML    Output          TAC
## 62    Fratio4010    Output          TAC
## 63         GB_CC    Output          TAC
## 64      GB_slope    Output          TAC
## 65     GB_target    Output          TAC
## 66      Gcontrol    Output          TAC
## 67         HDAAC    Output          TAC
## 68           ICI    Output          TAC
## 69          ICI2    Output          TAC
## 70        Iratio    Output          TAC
## 71       Islope1    Output          TAC
## 72       Islope2    Output          TAC
## 73       Islope3    Output          TAC
## 74       Islope4    Output          TAC
## 75          IT10    Output          TAC
## 76           IT5    Output          TAC
## 77      Itarget1    Output          TAC
## 78      Itarget2    Output          TAC
## 79      Itarget3    Output          TAC
## 80      Itarget4    Output          TAC
## 81           ITM    Output          TAC
## 82     L95target    Output          TAC
## 83    Lratio_BHI    Output          TAC
## 84   Lratio_BHI2    Output          TAC
## 85   Lratio_BHI3    Output          TAC
## 86      LstepCC1    Output          TAC
## 87      LstepCC2    Output          TAC
## 88      LstepCC3    Output          TAC
## 89      LstepCC4    Output          TAC
## 90      Ltarget1    Output          TAC
## 91      Ltarget2    Output          TAC
## 92      Ltarget3    Output          TAC
## 93      Ltarget4    Output          TAC
## 94           MCD    Output          TAC
## 95       MCD4010    Output          TAC
## 96      Rcontrol    Output          TAC
## 97     Rcontrol2    Output          TAC
## 98          SBT1    Output          TAC
## 99          SBT2    Output          TAC
## 100        SPmod    Output          TAC
## 101        SPMSY    Output          TAC
## 102      SPslope    Output          TAC
## 103        SPSRA    Output          TAC
## 104     SPSRA_ML    Output          TAC
## 105          YPR    Output          TAC
## 106       YPR_CC    Output          TAC
## 107       YPR_ML    Output          TAC
## 108        avgMP    Output          TAC
## 109        TCPUE    Output          TAC
## 110          THC    Output          TAC
## 111      FMSYref Reference          TAC
## 112    FMSYref50 Reference          TAC
## 113    FMSYref75 Reference          TAC
## 114        NFref Reference          TAC

You can access help documentation for the MPs in the usual fashion, for example:

?DCAC

5.3.1 Input Control MPs

Input controls allow some combination of adjustments to fishing effort, size selectivity, or spatial area.

The available input control MPs are:

avail("Input")
##  [1] "curE"        "curE75"      "DDe"         "DDe75"       "DDes"        "DTe40"       "DTe50"       "EtargetLopt"
##  [9] "ItargetE1"   "ItargetE2"   "ItargetE3"   "ItargetE4"   "ITe10"       "ITe5"        "LBSPR"       "LBSPR_MLL"  
## [17] "LstepCE1"    "LstepCE2"    "LtargetE1"   "LtargetE4"   "matlenlim"   "matlenlim2"  "minlenLopt1" "MRnoreal"   
## [25] "MRreal"      "slotlim"     "TCPUE_e"

Remember, to access help documentation:

?matlenlim

More information on input control MPs can be found in Beyond the Catch Limit.

5.3.2 Output Control MPs

The output control methods in the DLMtool provide a management recommendation in the form of a TAC. Some output controls are stochastic, allowing for uncertainty in the data or input parameters, and return a distribution of recommended TACs.

Output control methods are very common in fisheries management, especially in regions which have a tradition of managing fisheries by regulating the total amount of catch.

The available output controls are:

avail('Output')
##  [1] "AvC"         "BK"          "BK_CC"       "BK_ML"       "CC1"         "CC2"         "CC3"         "CC4"        
##  [9] "CC5"         "CompSRA"     "CompSRA4010" "CurC"        "DAAC"        "DBSRA"       "DBSRA_40"    "DBSRA4010"  
## [17] "DCAC"        "DCAC_40"     "DCAC_ML"     "DCAC4010"    "DCACs"       "DD"          "DD4010"      "DepF"       
## [25] "DynF"        "Fadapt"      "Fdem"        "Fdem_CC"     "Fdem_ML"     "Fratio"      "Fratio_CC"   "Fratio_ML"  
## [33] "Fratio4010"  "GB_CC"       "GB_slope"    "GB_target"   "Gcontrol"    "HDAAC"       "ICI"         "ICI2"       
## [41] "Iratio"      "Islope1"     "Islope2"     "Islope3"     "Islope4"     "IT10"        "IT5"         "Itarget1"   
## [49] "Itarget2"    "Itarget3"    "Itarget4"    "ITM"         "L95target"   "Lratio_BHI"  "Lratio_BHI2" "Lratio_BHI3"
## [57] "LstepCC1"    "LstepCC2"    "LstepCC3"    "LstepCC4"    "Ltarget1"    "Ltarget2"    "Ltarget3"    "Ltarget4"   
## [65] "MCD"         "MCD4010"     "Rcontrol"    "Rcontrol2"   "SBT1"        "SBT2"        "SPmod"       "SPMSY"      
## [73] "SPslope"     "SPSRA"       "SPSRA_ML"    "YPR"         "YPR_CC"      "YPR_ML"      "avgMP"       "TCPUE"      
## [81] "THC"

5.3.3 Mixed MPs

Mixed MPs return a combination of input and output controls. Currently there are only a few mixed MPs in DLMtool, and these were developed simply for demonstration purposes. They may not work very well! See Developing Custom Management Procedures for more information on developing your own mixed MPs. And please share them with us, we’d love to add them to DLMtool!

avail('Mixed')
## [1] "AvC_MLL"      "Itarget1_MPA"

5.3.4 Reference MPs

The final type is the reference MPs. These MPs are not designed to be used in practice, but are useful for providing a reference for comparing for the performance of other MPs. For example, the FMSYref and NFref methods (fishing perfectedly at F[MSY] and no fishing at all) can be useful for framing realistic performance with respect to a set of management objectives.

The available reference MPs are:

avail('Reference')
## [1] "FMSYref"   "FMSYref50" "FMSYref75" "NFref"