FSAdata (version 0.3.0)

SnapperHG1: Age (subsample) and length (all fish) of Snapper from two survey locations.

Description

A large sample (not random or proportional) of Snapper (Pagrus auratus) were aged from otoliths, with the remainder of the fish just measured for length. Note that age-20 is actually age 19+.

source

Data re-created from Tables 2, 3, and 5 in Davies, N.M. and C. Walsh. 2002. http://fs.fish.govt.nz/Page.aspx?pk=113&dk=22516{Snapper age and length samples from Kaharoa research trawl surveys KAH8810 and KAH0012 of the Hauraki Gulf.} Final Research Report for Ministry of Fisheries Research Project SNA2000/01. National Institute of Water and Atmospheric Research. [Note that the unaged fish were simulated from Table 5 assuming that the total number of fish was large enough that at least one fish was observed in each cell where a proportion was listed.]

Topic(s)

• Age-length key

concept

'Age-Length Key'

Examples

data(SnapperHG1)
str(SnapperHG1)
head(SnapperHG1)

## Extract one of the sample surveys
sn1 <- subset(SnapperHG1,survey=="KAH8810")

## Extract the aged sample
sn1.aged <- subset(sn1,!is.na(age))
str(sn1.aged)

## Extract the length sample
sn1.length <- subset(sn1,is.na(age))
str(sn1.length)