agesurvcl {fishmethods}

Age-Based Survival and Mortality Estimators for Cluster Sampling

Description

Calculates the survival and mortality estimators of Jensen (1996) where net hauls are treated as samples

Usage

agesurvcl(age = NULL, group = NULL, full = NULL, last = NULL)

Arguments

age

the vector of ages. Each row represents the age of an individual.

group

the vector containing variable used to identify the sampling unit (e.g., haul). Identifier can be numeric or character.

full

the fully-recruited age.

last

the maximum age to include in the calculation. If not specified, the oldest age is used.

Details

The individual age data are tabulated and subsetted based on full and last. The calculations follow Jensen(1996). If only two ages are present, a warning message is generated.

Value

Matrix containing estimates of annual mortality (a), annual survival (S), and instantaneous total mortality (Z) and associated standard errors.

Author(s)

Gary A. Nelson, Massachusetts Division of Marine Fisheries [e-mail]

References

Jensen, A. L. 1996. Ratio estimation of mortality using catch curves. Fisheries Research 27: 61-67.

See Also

agesurv

Examples

data(Jensen)
agesurvcl(age=Jensen$age,group=Jensen$group,full=0)