For example, the logbook data for the SARLF, like the monitoring data for most other fisheries, are not completely independent, and interdependence among observations can bias estimates of parameters.
There are several reasons why the data from the SARLF may provide a useful measure of the relative abundance of octopus over these spatial and temporal scales.
The higher total catches and catch rates of both lobster and octopus in the SZ, compared to the NZ, probably reflect the more extensive reef habitat and more intense nutrient-enrichment upwelling in this portion of the SARLF (Lewis, 1981).
Because large lobsters can be worth more and produce more eggs than smaller lobsters, the increased mortality rates of large lobsters suggest that the total economic and ecological impacts of octopus predation in the SARLF are greater than indicated by the absolute number of lobsters killed.
Octopus predation of lobsters in traps is a significant problem in the SARLF.