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Specify the harvest control rule (HCR) used for Rceattle

Source: R/0-build_hcr.R
build_hcr.Rd

Defines the harvest control rule and its associated reference points. The rules are tabulated, with which ones work under predation, in vignette("projections-and-reference-points"); the formulations of the three ramped rules are below.

Usage

build_hcr(
  HCR = 0,
  DynamicHCR = FALSE,
  Ftarget = 0.4,
  Flimit = 0.35,
  Ptarget = 0.4,
  Plimit = 0,
  Alpha = 0.05,
  Pstar = 0.45,
  Sigma = 0.5,
  Fmult = 1,
  HCRorder = 1
)

Arguments

HCR

Harvest control rule, as an integer or string alias: 0/"NoFishing" (no catch, hindcast only), 1/"CMSY" (maximize joint catch, optionally holding depletion at or above Plimit), 2/"ConstantF" (constant input F at Ftarget), 3/"ConstantFSSB" (the F reaching Ftarget percent of SSB0 by the end of the projection), 4/"ConstantFSPR" (constant Fspr, scalable by Fmult following NEFSC), 5/"NPFMC", 6/"PFMC" or 7/"SESSF". Default 0. Only 0, 1, 2, 3 and 6 work in multispecies mode.

DynamicHCR

TRUE/FALSE. Use dynamic rather than static reference points (default FALSE).

Ftarget

Target fishing mortality rate (yr^-1), SPR- or depletion-based, or the input F for projections. For SPR F40%, enter 0.40.

Flimit

Limit fishing mortality rate (yr^-1), SPR- or depletion-based. For SPR F35%, enter 0.35.

Ptarget

Target spawning-stock biomass as a proportion of static or dynamic spawning-stock biomass at F = 0. For B40%, enter 0.40.

Plimit

Limit spawning-stock biomass on the same basis. For B10%, enter 0.10.

Alpha

Parameter used in the NPFMC Tier 3 rule.

Pstar

Quantile for the uncertainty buffer, given Flimit and Sigma.

Sigma

Standard deviation of the normal uncertainty buffer, given Flimit and Pstar.

Fmult

Multiplier on the target F (default 1), scaling it following NEFSC convention.

HCRorder

For multispecies models, the order in which to project fishing (predators first, then prey, for instance).

Value

A list containing the harvest control rule and associated biological reference points.

Details

hcr = 5 or "NPFMC", the North Pacific Fishery Management Council Tier 3 spawner-per-recruit rule: Stock status: \(SB > SB at Ftarget\) $$Fofl = Flimit$$ $$Fuse = Ftarget$$ Stock status: \(Alpha < SB / SB at Ftarget \le 1\) $$Fofl = Flimit * (SB / SB_{Ftarget} - Alpha) / (1 - Alpha)$$ $$Fuse = Ftarget * (SB / SB_{Ftarget} - Alpha) / (1 - Alpha)$$ Stock status: \(SB / SB at Ftarget \le Alpha\) or \(SB < Plimit * SB0\) $$Fofl = 0$$ $$Fuse = 0$$

hcr = 6 or "PFMC", the Pacific Fishery Management Council category 1 40-10 annual catch limit rule (PFMC 2020), using Fspr in single species or the F reaching X% of SSB0 under predation. The uncertainty buffer is qnorm(Pstar, Flimit, Sigma), which equals Flimit + qnorm(Pstar, 0, Sigma) and so sits below Flimit when \(Pstar < 0.5\). The taper runs between \(SB0 * Plimit\) and \(SB0 * Ptarget\), so the 40-10 shape needs Ptarget = 0.40 and Plimit = 0.10; the default Plimit = 0 gives a 40-0 rule. Stock status: \(SB > SB0 * Ptarget\) $$Fofl = Flimit$$ $$Fuse = qnorm(Pstar, Flimit, Sigma)$$ Stock status: \(SB0 * Plimit < SB \le SB0 * Ptarget\) $$Fofl = Flimit$$ $$Fuse = qnorm(Pstar, Flimit, Sigma) * \frac{SB0 * Ptarget * (SB - SB0 * Plimit)}{SB * SB0 * (Ptarget - Plimit)}$$ Stock status: \(SB < SB0 * Plimit\) $$Fofl = 0$$ $$Fuse = 0$$

hcr = 7 or "SESSF", the Southern and Eastern Scalefish and Shark Fishery Tier 1 spawner-per-recruit rule, with F_Limit = F_(20%) and B_Limit = SB_20 (AFMA 2017): Stock status: \(SB > SB0 * Ptarget\) $$Fofl = Flimit$$ $$Fuse = Ftarget$$ Stock status: \(SB0 * Ptarget > SB > SB0 * Plimit\) $$Fofl = Flimit * (SB / (SB0 * Plimit) - 1)$$ $$Fuse = Ftarget * (SB / (SB0 * Plimit) - 1)$$ Stock status: \(SB < SB0 * Plimit\) $$Fofl = 0$$ $$Fuse = 0$$

Examples

# Tier 3 NPFMC control rule: F40% as FABC, F35% as FOFL.
build_hcr(HCR = "NPFMC", DynamicHCR = FALSE, Ftarget = 0.4, Flimit = 0.35)
#> $HCR
#> [1] "NPFMC"
#> 
#> $DynamicHCR
#> [1] FALSE
#> 
#> $Ftarget
#> [1] 0.4
#> 
#> $Flimit
#> [1] 0.35
#> 
#> $Ptarget
#> [1] 0.4
#> 
#> $Plimit
#> [1] 0
#> 
#> $Alpha
#> [1] 0.05
#> 
#> $Pstar
#> [1] 0.45
#> 
#> $Sigma
#> [1] 0.5
#> 
#> $Fmult
#> [1] 1
#> 
#> $HCRorder
#> [1] 1
#> 

# No fishing: the projection a B0 reference point is read from.
build_hcr(HCR = "NoFishing")
#> $HCR
#> [1] "NoFishing"
#> 
#> $DynamicHCR
#> [1] FALSE
#> 
#> $Ftarget
#> [1] 0.4
#> 
#> $Flimit
#> [1] 0.35
#> 
#> $Ptarget
#> [1] 0.4
#> 
#> $Plimit
#> [1] 0
#> 
#> $Alpha
#> [1] 0.05
#> 
#> $Pstar
#> [1] 0.45
#> 
#> $Sigma
#> [1] 0.5
#> 
#> $Fmult
#> [1] 1
#> 
#> $HCRorder
#> [1] 1
#>