Preparing for the Year of the Skate: proposed information collection and tagging protocol for skates

Skates are an important bycatch of the toothfish fishery in the CCAMLR area and have been identified as priority taxa for which assessments of status are required (e.g., SC-CCAMLR XXIII 2004, paragraphs 4.172, 4.177 and 4.199). While Dunn et al. (2007) and Agnew et al. (2007) have developed preliminary assessment models for skates, they also highlighted that further information was required before a full assessment can be carried out. In 2007, CCAMLR-SAM-WG recommended (CCAMLR XXVI WG-SAM paragraph 8.10) a review of data requirements and a “Year of the Skate” for 2008–09 whereby data collection effort on bycatch will be concentrated on skate species in that year in order to inform a full skate assessment.
This paper discusses improvements to the fishery derived data that may be required to better inform an assessment of Ross Sea skates. We propose options for the appropriate collection of such data from the fishery and a revised skate tagging protocol. These changes could be piloted in the 2007–08 season by all or a subset of vessels fishing in the Ross Sea. The results from the pilot study may be useful to inform modifications to data collection systems that would be required in 2008–09, for the “Year of the Skate”. Note that we do not consider other information requirements such as determining biological parameters.