fishmethods (version 1.3-0)

convmort: Conversion of Mortality Rates

Description

Convert instantaneous fishing mortality rate (F) to annual exploitation rate (mu) and vice versa for Type I and II fisheries.

Usage

convmort(value = NULL, fromto = 1, type = 2, M = NULL)

Arguments

value

mortality rate

fromto

conversion direction: 1=from F to mu; 2 = from mu to F. Default is 1.

type

type of fishery following Ricker (1975): 1=Type I; 2=Type II. Default is 2.

M

natural mortality rate (for Type II fishery)

Value

• A vector of the same length as value containing the converted values.

Details

Equations 1.6 and 1.11 of Ricker (1975) are used.

References

Ricker, W. E. 1975. Computation and interpretation of biological statistics of fish populations. Bull. Fish. Res. Board. Can. 191: 382 p.

Examples

convmort(0.3,fromto=1,type=2,M=0.15)