| dc.description.abstract | A survey design for estimating the length distribution of harvested southern rock lobsters (Jasus edwardsii)
was developed for the South Australian fishery. Experimental sampling was carried out by volunteer fishers in spring
1996 and autumn 1997 to test three proposed survey designs. A variance components analysis indicated that it would
be more efficient to sample one pot per trip from all trips rather than the previous design of sampling multiple pots
from a few trips. The variation among licenses (fishers) accounts for most of the remaining sample variance. Onboard
research sampling by scientists, who in the past measured from all pots on selected trips, was shown to be the least efficient
design option in comparison with volunteer sampling by fishers. A sampling protocol where fishers measure one
to three pots per trip has been adopted by the South Australian rock lobster fishers. Estimators, based on a three-level
sampling hierarchy of pot, day, and license, are presented for estimating the mean and sample variance of the numbers
harvested overall and within each length category. | en |
