fishmethods (version 1.4-0)

catchsurvey: Catch-Survey Analysis

Description

This function applies the catch-survey analysis method of Collie and Kruse (1998) for estimating abundance from catch and survey indices of relative abundance

Usage

catchsurvey(year = NULL, catch = NULL, recr = NULL, post = NULL, M = NULL,
 T = NULL, phi = NULL, w = 1, initial = c(NA,NA,NA),uprn = NA, graph = TRUE)

Arguments

year

vector containing the time series of numeric year labels.

catch

vector containing the time series of catch (landings) data.

recr

vector containing the time series of survey indices for recruit individuals.

post

vector containing the time series of survey indices for post-recruit individuals.

M

instantaneous natural mortality rate. Assumed constant throughout time series

T

proportion of year between survey and fishery.

phi

relative recruit catchability.

w

recruit sum of squares weight.

initial

initial recruit estimate,initial postrecruit estimate in year 1, and initial catchability estimate.

uprn

the upper bound for the recruit and postrecruit estimates.

graph

logical indicating whether observed versus predicted recruit and post-recruit indices, total abundance and fishing mortality should be plotted. Default=TRUE.

Value

• List containing the estimate of catchability, predicted recruit index by year (rest), estimate of recruit abundance (R), predicted post-recruit index by year (nest), post-recruit abundance (N), total abundance (TA: R+N), total instantaneous mortality (Z), and fishing mortality (Fmort)

Details

Details of the model are given in Collie and Kruse (1998).

References

Collie JS and GH Kruse 1998. Estimating king crab (Paralithodes camtschaticus) abundance from commercial catch and research survey data. In: Jamieson GS, Campbell A, eds. Proceedings of the North Pacific Symposium on Invertebrate Stock Assessment and Management. Can Spec Publ Fish Aquat Sci. 125; p 73-83. See also Collie JS and MP Sissenwine. 1983. Estimating population size from relative abundance data measured with error. Can J Fish Aquat Sci. 40:1871-1879.

Examples

## Example take a bit of time to run
  data(nshrimp)
   catchsurvey(year=nshrimp$year,catch=nshrimp$C,recr=nshrimp$r,post=nshrimp$n,M=0.25,T=0.5,phi=0.9,w=1,
       initial=c(500,500,0.7),uprn=10000)