Spawning biomass per recruit, by origin and destination region

The age-and-region projection behind Get_Det_Recruitment's Beverton-Holt and Ricker curves: one recruit per origin region is projected through every age, season and the plus-group, unfished and fished. This depends only on mortality, selectivity and movement, never on R0, spawning biomass or the current year, so a caller that holds those fixed across years (as the annual cycle does; see det_rec_args in Simulate_Pop_Static) should build this once and pass it back into Get_Det_Recruitment as sbpr_table, rather than paying for this projection again on every year it is otherwise identical.

Usage

Get_SBPR_Table(
  rec_dd,
  rec_region_prop,
  rec_seas_prop,
  n_pop,
  n_regions,
  n_ages,
  n_fish_fleets,
  WAA,
  MatAA,
  natmort,
  Movement,
  sgl_seas_spawning_movement,
  do_recruits_move,
  t_spawn,
  init_F,
  dmr,
  fish_sel,
  ret_sel,
  n_seas,
  spawn_seas,
  seasdur,
  sexratio_f,
  Mrate = NULL,
  move_timing = 0,
  expm_nsub = 0
)

Arguments

rec_dd

Integer. 0 = density dependence within each population or region, 1 = shared across regions, valid only when n_pop = 1.

rec_region_prop

Matrix (n_pop × n_regions) of the proportion of recruitment allocated to each region.

rec_seas_prop

Matrix (n_pop × n_seas) of seasonal recruitment proportions. Must be zero before spawn_seas when rec_lag = 0.

n_pop

Number of populations.

n_regions

Number of spatial regions.

n_ages

Number of age classes (including the plus group).

n_fish_fleets

Integer. Number of fishery fleets.

WAA

Array (n_pop × n_regions × n_seas × n_ages) of weight-at-age.

MatAA

Array (n_pop × n_regions × n_seas × n_ages) of maturity-at-age.

natmort

Array (n_pop × n_regions × n_seas × n_ages) of natural mortality, a rate per year in each season.

Movement

Array (n_pop × origin × destination × n_seas × n_ages) of seasonal movement probabilities.

sgl_seas_spawning_movement

Array (n_pop × origin × destination × n_ages) of spawning movement when a single season is used and n_pop > 1.

do_recruits_move

Indicator for whether recruits move in their first year.

t_spawn

Fraction of the spawning season that occurs before spawning.

init_F

Array (n_regions × n_seas × n_fish_fleets) of initial fishing mortality.

dmr

Array (n_regions × n_seas × n_fish_fleets) of initial (first year) discard mortality.

fish_sel

Array (n_pop × n_regions × n_seas × n_ages × n_fish_fleets) of total fishery selectivity.

ret_sel

Array (n_pop × n_regions × n_seas × n_ages × n_fish_fleets) of retained fishery selectivity.

n_seas

Number of seasons per year.

spawn_seas

Season index in which spawning occurs.

seasdur

Numeric vector (n_seas) of seasonal durations as fractions of a year.

sexratio_f

Matrix (n_pop × n_regions) of female recruitment proportions.

Value

List of phi0 and phiF, the unfished and fished spawning biomass per recruit at R0 = 1: a [pop x region] matrix under rec_dd = 0, a scalar under rec_dd = 1. Get_Det_Recruitment recovers S0/SF by scaling these by R0.