The Working Group on Improving the use of Survey Data for Assessment and Ad-vice (WGISDAA) met at Le centre Ifremer Atlantique à Nantes, France, 21–23 January 2014, under the Co-Chairmanship of David Reid, Ireland, and Stephen Smith, Cana-da. In addition there were four participants from the following ICES countries; Den-mark, England, France, and Portugal. The timing and location of this meeting was set to coincide with the annual meeting of the Working Group on Integrating Surveys for the Ecosystem Approach (WGISUR) to facilitate joint sessions on providing guidance on the adaptation of existing surveys to provide ecosystem data (see agenda item 1 below).
The meeting had three agenda items for discussion.
1 ) Evaluate the potential impacts of adding ecosystem data collection activi-ties on surveys currently collecting abundance indices in terms of changes to the precision of the fish stock estimates. Work to be done in separate and joint sessions with WGISUR.
2 ) Future of WGISDAA
3 ) Evaluate the new survey Ifremer is planning for ICES area VIIde
One of the anticipated impacts of adding more ecosystem data collection to cruises collecting data for fish abundance indices is a decrease in the number of tows or tran-sects devoted to this latter purpose. In turn, the impact in the reduction of tows for abundance indices is expected to be reflected in a decrease in the precision (or in-crease in CV) for the abundance estimates. Three case studies were presented for surveys where estimates of CV were available to evaluate the impacts of reducing the number of tows. The impacts were case specific and depended upon spatial distribu-tion and current sampling levels. Impacts on non-target species and other infor-mation collected on the survey also need to be considered. Survey design changes to mitigate losses of precision for the current design were also discussed. The potential for using the additional environmental data as covariates to improve precision esti-mates for the fish estimation in the survey should be explored. In the end, the most important issue may be the impact of reduced precision for the abundance indices on the stock assessment advice. A recently published study was presented that evaluat-ed changes in survey sampling levels on stock assessment model results and showed that while there was a predictable change in precision of the model results, there could also be changes in trend and stock status. Most ICES surveys do not provide CVs nor do ICES assessments currently include survey CVs in their models and therefore it will be difficult to evaluate the impacts of reductions in survey tows on abundance indices and stock assessment model results.
This was the third annual meeting of this working group and it was also the most poorly attended of all of the meetings. Past reports of this working group have com-mented on the difficulty in soliciting agenda items and associated researchers for meetings and this meeting was no exception. While a number of working groups had identified potential agenda items in their annual recommendations in autumn of 2013, there did not seem to be anyone available from the working groups to present information on the items and explain the request. We believe that the original reason for creating WGISDAA still exists and that it is worthwhile to encourage other WGs to look to our working group to deal with issues concerning survey data and stock assessments. A number of approaches to improve the interaction with other working groups were discussed such as replacing the annual meeting with periodic work-shops focusing on a particular set of issues, or forming a crises team that can be called in an ad hoc basis. No matter how the meetings are scheduled, WGISDAA will con-sider requests from the survey and assessment working groups but there must be enough lead time and commitment on everyone’s part to work on solutions to the questions raised before the meeting and to participate in the review meeting. . De-fault involvement in Benchmark working groups would be an initial first step. Chairs of these working groups and ICES staff should identify any issues relating to the use of the fishery-independent data sources and refer these to WGISDAA. The scale, quantity, timing and workload of such requests would have to be considered, but priorities could be established and the work of WGISDAA focused on that basis. We would suggest that this could be the primary route for referral, however, we could also suggest a further avenue of approach directly to survey or assessment EG to identify this type of issue BEFORE it reaches the level of the benchmark.
Ifremer’s plans for a new survey series in the western English Channel (CAMANOC) were presented for information only to the working group.