A Harvest Control Rule using B/BMSY and F/FMSY to adjust TAC or TAE.
HCR_FB(Brel, Frel, Bpow = 2, Bgrad = 1, Fpow = 1, Fgrad = 1)
improper fraction: an estimate of Biomass relative to BMSY
improper fraction: an estimate of Fishing mortality rate relative to FMSY
non-negative real number: controls the shape of the biomass adjustment, when zero there is no adjustment
non-negative real number: controls the gradient of the biomass adjustment
non-negative real number: controls the adjustment speed relative to F/FMSY. When set to 1, next recommendation is FMSY. When less than 1 next recommendation is between current F and FMSY.
improper fraction: target Fishing rate relative to FMSY
a TAC or TAE adjustment factor.
Made up for this package
res <- 100 Frel <- seq(1/2, 2, length.out = res) Brel <- seq(0.05, 2, length.out=res) adj <- array(HCR_FB(Brel[rep(1:res, res)], Frel[rep(1:res, each = res)], Bpow = 2, Bgrad = 1, Fpow = 1, Fgrad = 0.75), c(res, res)) contour(Brel, Frel, adj, nlevels = 20, xlab = "B/BMSY", ylab = "F/FMSY", main = "FBsurface TAC adjustment factor") abline(h = 1, col = 'red', lty = 2) abline(v = 1, col = 'red', lty = 2) legend('topright', c("Bpow = 2", "Bgrad = 1", "Fpow = 1", "Fgrad = 0.75"), text.col = 'blue')