SAMtool (version 1.7.0)

HCR_escapement: Fixed escapement harvest control rule

Description

A simple control rule that allows fishing when the operational control point (OCP) is above some threshold. By default, this function sets the TAC at F = 100% FMSY when spawning depletion > 0.1.

Usage

HCR_escapement(
  Assessment,
  reps = 1,
  OCP_type = "SSB_SSB0",
  OCP_threshold = 0.2,
  Ftarget_type = "FMSY",
  relF_max = 1,
  ...
)

Value

An object of class MSEtool::Rec with the TAC recommendation.

Arguments

Assessment

An object of class Assessment with estimates of FMSY or UMSY and vulnerable biomass in terminal year.

reps

The number of stochastic samples of the TAC recommendation.

OCP_type

The type of operational control points (OCPs) for the harvest control rule used to determine whether there is fishing. By default, use ("SSB_SSB0" for spawning depletion. Other biomass OCPs include "SSB_SSBMSY" for spawning biomass relative to MSY and "SSB_dSSB0", for dynamic depletion (dynamic SSB0 is the historical reconstructed biomass with F = 0). For F-based OCPs, the terminal year fishing mortality relative F01 or Fmax (using yield-per-recruit) or F-SPR% (see SPR_OCP argument) can be used.

OCP_threshold

The value of the OCP above which fishing can occur.

Ftarget_type

The type of F used for the target fishing mortality rate.

relF_max

The relative value of Ftarget if OCP > OCP_treshold.

...

Miscellaneous arguments.

Author

Q. Huynh

Details

The catch advice is calculated using the catch equation of the corresponding assessment. See Assessment@forecast$catch_eq, a function that returns the catch advice for a specified Ftarget.

References

Deroba, J.J. and Bence, J.R. 2008. A review of harvest policies: Understanding relative performance of control rules. Fisheries Research 94:210-223.

See Also

make_MP HCR_ramp

Examples

# create an MP to run in closed-loop MSE (fishes at FMSY when B/B0 > 0.2)
SP_escapement <- make_MP(SP, HCR_escapement)

# The MP which fishes at 75% of FMSY
SP_escapement75 <- make_MP(SP, HCR_escapement, relF_max = 0.75)

# The MP which fishes at FMSY when BMSY > 0.5
SP_BMSY_escapement <- make_MP(SP, HCR_escapement, OCP_type = "SSB_SSBMSY", 
                              OCP_threshold = 0.5, relF_max = 1)

# \donttest{
myOM <- MSEtool::runMSE(MSEtool::testOM, MPs = c("FMSYref", "SP_escapement", "SP_BMSY_escapement"))
# }