ricker {MQMF}

ricker one version of the Ricker stock recruitment

Description

ricker implements the Ricker stock recruitment equation where R = aBexp(-bxB), R is the recruitment, a and b are the parameters and B is the spawning biomass. a is recruits-per-spawner at low stock levels, and b relates to the decline in recruitment as spawning biomass increases.

Usage

ricker(p, B)

Arguments

p

a vector of length two of the a and b parameters

B

a vector, possibly of length 1, of spawning biomass levels

Value

a vector of length = to B of predicted recruitments

Examples

  B <- 1:10000
  rec <- ricker(c(10,0.0002),B)
  oldpar <- par(no.readonly=TRUE)
  plot1(B,rec,xlab="SpB",ylab="Recruitment",lwd=2)
  par(oldpar)