A working session to provide guidance on estimating the bycatch of rare-event species, particularly seabirds and marine mammals, was convened at the AFSC on 22 June 2009. Participants included representatives from the AFSC the NMFS Alaska Regional Office; the Northwest, Pacific Islands, Southwest, and Northeast Fisheries Science Centers; and the University of Washington.
The day's focus was to advise the AFSC on how to provide annual estimates of bird and mammal bycatch. Discussions noted mandated reporting requirements and general needs of end-users. Presentations were provided on coverage and observer sampling methods, the Alaska Region Catch Accounting System, and current bycatch estimation and modeling efforts in the Pacific Islands and Northeast Atlantic areas.
Participants noted that there was a strong dichotomy between an automated annual system where one would use ratio estimators, versus a more sophisticated system that would require much more analysis and examination of the data with respect to frequency of observations of no seabird or marine mammal bycatch. Having an estimation procedure that is well documented and repeatable was noted as a priority.
A report is being developed that will describe the day's efforts in more detail and will provide a list of recommendations. Generally, the AFSC plans to work with the Alaska Region's Catch Accounting System to support the annual production of seabird bycatch estimates while also looking into longer-term comparative modeling exercises to evaluate the effectiveness of this ratio-estimator based approach.
