Estimating the level of illegal fishing using simulated scaling methods on detected activity

At its 2003 meeting, WG-FSA recommended that investigations be undertaken to determine whether the method for estimating catches from illegal, unregulated or unreported (IUU) fishing developed by Agnew and Kirkwood (2002) for Subarea 48.3 could be applied to other CCAMLR areas (SC-CAMLR-XXII, Annex 5, paragraph 3.18).
The results of these simulations suggest that more information on IUU fleet dynamics, particularly evasion tactics, will be necessary to devise an observation strategy for estimating the number of IUU fishing days, particularly for areas where patrolling may be relatively infrequent or prone to evasion. Also, the assessment method may need to be refined to take these issues into account.
An important consideration for the future will be the inevitable tension for fishery patrol vessels between detecting IUU activity, thereby estimating the number of IUU fishing days, and deterring such activity. For assessment purposes, this highlights a general problem that the method of observation has a strong effect on the behaviour of the system (of the illegal fishing cruises). It may be necessary to develop other forms of observations to facilitate this task.