Testing the MULTIFAN-CL assessment model using simulated tuna fisheries data

Data sets similar to those available on yellowfin tuna (Thunnus albacares) fisheries of the western and central Pacific ocean (WCPO) were generated by numerical simulations, and then analyzed with a recently developed statistical catch-at-age model (MULTIFAN-CL) to assess its performance under different conditions concerning data availability, observation errors, and fishery complexity. Given a 37-year time series of catch, standardized fishing effort, catch length frequencies, all stratified by period, region and fishery, MULTICAN-CL provided estimates of several population and fishery parameters that were relatively close to the simulated values. The least biased estimates were obtained with more informative data sets obtained from more complex fishery scenarios with greater spatial stratification. For such cases, estimates of some precautionary reference points were within +/- 12% of the simulated values. Additional tests are proposed assess the effects of alternative sources of information and different errors on the accuracy of various estimates and reference points computed with this model. (C) 2004 Elsevier B.V. All rights reserved.