Key considerations for planning a large-scale krill survey

Article II of the Convention requires the Commission to maintain harvested populations above levels that ensure stable recruitment. WG-EMM is currently developing candidate feedback management (FBM) approaches for the krill stock in subareas 48.1 to 48.4. These approaches include some which adjust fishing (catch, effort, location or timing) based on information about stock size. Thus CCAMLR needs reliable indicators of krill stock size at appropriate spatial scales. It is likely that future FBM approaches will require regular information on krill stock size at relatively fine spatial scales (subarea or less). However, periodic large-scale surveys (comparable to the CCAMLR 2000 synoptic survey) might also play a role in the future management of the krill fishery. Such surveys provide an indication of krill biomass at the larger scale which is robust to uncertainties about krill flux. Current constraints on research funding suggest that coordinated mobilization of multiple research vessels, as in 2000, is now unlikely. However, future large-scale surveys may be possible with the engagement of the fishing industry. We recommend that any such large scale surveys should be coordinated through CCAMLR’s scientific working groups. We identify the key components of a large-scale survey and the key technical and resource issues that must be addressed. We suggest that CCAMLR’s working groups should establish a process for addressing these issues if these groups consider that large-scale surveys are likely to be important in the future management of the krill fishery. The design of the CCAMLR 2000 survey might be a useful basis for designing future surveys, subject to a review which should be the first task in preparing for a future survey.