CatDyn (version 1.1-1)

M.Hoenig: Estimate natural mortality rate from longevity data

Description

Using the empirical regression parameters obtained by Prof. John M. Hoenig and the longevity provided with max.age, estimate the natural mortality rate and its standard error from application of the delta method.

Usage

M.Hoenig(max.age, time.step)

Arguments

max.age

Numeric, longevity in years.

time.step

Character, either day, week, or month, the desired unit of the estimate.

Value

A length 2 numeric vector with estimated natural mortality and its standard error.

Details

This function can be used to obtain a good initial value for natural mortality rate to be input in the exploratory or statistical feet of a catch dynamics model, at the time step in which the model will be run.

References

Hoening, J.M. 2005. Empirical use of longevity data to estimate mortality rates. SEDAR33-RD17. SEDAR, North Charleston, SC. 8 pp.

Examples

# NOT RUN {
max.age <- 5.8
time.step <- "day"
M.Hoenig(max.age,time.step)
# }