CCAMLR measures regulating the tagging of Dissostichus species, metrics used to assess vessel tagging performance, the potential for some anomalous results, and general recommendations on tagging; a view from the hauling room

The background to the current CCAMLR toothfish tagging programme is reviewed and recent performance measures implemented by CCAMLR to control and monitor the tagging of toothfish (Dissostichus species) in exploratory fisheries carried out within the Convention Area are described.  Following the first season of implementation we describe several circumstances which will cause anomalies in the tag overlap statistic used to monitor tagging performance.  These relate to differences in the length distribution of Dissostichus species within the assessed management division (ASD) or changes in the tagging rate within sub areas of the assessed ASD.  The current level of two tonnes of Dissostichus catch triggering the requirement to achieve a tag overlap statistic of 60% or more for upcoming season as specified in Annex 41-01/C is evaluated by means of simple simulations.  The results of this analysis indicate that at low levels of tagging, equating to between 2 and 10 t of Dissostichus catch, there is a strong likelihood that a breach of the Measure would occur.  We make recommendations from a user perspective on other aspects of toothfish tagging such as crew participation in the process, tag colour, training, and clarification of the controlling measures. We also recommend that the CCAMLR tagging protocol be updated and translated.