Calculate F%SPR: the fishing mortality that reduces the spawning biomass per recruit (SBR) to X % of those without fishing (SPR0).

Calcu_SPR_X calculates F%SPR (the fishing mortality that reduce the spawning biomass per recruit (SBR) to X % of those without fishing (SPR0)).

Usage

Calcu_SPR_X(x, M, Sel, w, g, A = 6, F_max = 2)

Arguments

x

The proportion (X) to calculate F% SPR. This parameter should be provided as a proportion (i.e. within the range from 0 to 1). Defalut is 0.2.

M

A vector of natural mortality rate at age a. The length should be A+1.

Sel

A vector of selectivity at age a. The length should be A+1.

w

A vector of weight at age a. The length should be A+1.

g

A vector of maturity at age a. The length should be A+1.

A

Plus group age. Default is 6.

F_max

This value should be large enough so that the true F%SPR value be included (otherwise a warning message appears). Defalut is 1.

Value

A value of F% SPR.