abdat {MQMF}

abdat A list of fishery data for blacklip abalone

Description

A dataset of fishery data for blacklip abalone (Haliotis rubra) from part of the Tasmanian west coast for the years 1985 - 2008. It contains a data.frame containing the year, the catch, and the standardized CPUE from four statistical blocks of Tasmania's west coast combined. In particular, it can be used when fitting a surplus production model. Workable initial parameter values, before log-transformation might be: r= 0.4, K=9400, Binit=3400, sigma=0.05 for the Schaefer version, while these also work for the Fox model one could more efficiently use r=0.3, K=12000, Binit=4000, sigma=0.05.

Format

A data.frame of three columns

year

the annual year in which the catches occurred

catch

the reported landed catch in tonnes, to the nearest kilogram

cpue

the standardized catch-per-unit-effort for this dive fishery

Subjects

• Surplus Production Modelling, Schaefer and Fox models

• Model fitting using maximum likelihood

• Uncertainty examples

Source

Catch data from Mundy, C. and J. McAllister (2019) Tasmanian abalone fishery assessment 2018, Institute for Marine and Antarctic Studies, University of Tasmania, 190p. ISBN: 978-1-925646-46-7. The cpue data is an unpublished early attempt at standardizing the cpue data with respect to month, block, and diver. Many more details are now included in such analyses.

Examples

 data(abdat)
 print(abdat)
 oldpar <- par(no.readonly=TRUE)
 plot(abdat$year,abdat$cpue, type="l",xlab="year",ylab="CPUE",
      panel.first=grid())
 points(abdat$year,abdat$cpue,pch=16,cex=1.2)
 par(oldpar)