REPORT OF THE STANDING COMMITTEE ON RESEARCH ... - Iccat

ICCAT REPORT 2008-2009 (I)Appendix 5WORK PLANS OF THE SPECIES GROUPS FOR 2009Tropical Tunas Species Work Plan for 2009An understanding of natural mortality, growth, stock structure and movement is of fundamental importance inconducting stock assessments. Recent analyses conducted by the Tropical Tunas Species Group have confirmedthe sensitivity of current models to such basic biological parameters. The Group places a high priority on theimproved quantification of these factors.Tag-recapture studies are an important tool in addressing these biological questions. Recent projects have greatlyexpanded the available ICCAT tagging database for tropical tunas. The Tropical Tunas Species Group proposesthat a workshop be held in 2009 to jointly analyze these data. The Secretariat should make the current tropicaltunas tagging database available to national scientists early in 2009, for the purpose of providing an opportunityto conduct preliminary analyses in preparation for this workshop, including full validation and correction of thetagging database.The Species Group also recommends data-mining efforts by the ICCAT Secretariat and national scientists torecover tagging data available for the period 1970-1980. These data were used in the past for scientific analysesof tropical species, but they are not currently available in the ICCAT database.Albacore Work PlanOverviewIn July 2007 the assessment of both North and South Atlantic albacore stocks was carried out. The assessment ofthe North Atlantic stock indicated that the stock is overfished. This result indicates a need to continue monitoringthe catch rates (standardized CPUEs) for all the major fleets exploiting this stock, mainly the surface fisheriesrelative abundance indices. Furthermore, uncertainty on some biological parameters (growth and reproductivebiology) should be studied further for both the North stock and the South stock. Moreover, abiotic variablesaffecting the distribution of immature and adult albacore in the Atlantic shall be investigated, as well as themarket price as an indicator of the catch trend.The basic input data according to statistical requirements and the need to obtain fishery independent data havebeen pointed out as a way to discern if the status of the stock corresponds to the analyses performed using onlyfishery dependent data.As for the Mediterranean stock, basic information of Task I and Task II data from the fisheries is incomplete andbiological information of the stock is still poor.The 2007 Commission meeting resumed in Recommendation 07-02 to conduct an assessment of the North stockin 2009.North stock schedule for tasks to be done prior to the assessment session in 2009Data (Task I and Task II) up to 2007 will be analyzed for assessment of the status of stock and shall be availableby May 15, 2009. In this way the Secretariat will proceed to update (2005-2007) the sampling data base neededfor Multifan-CL modeling by May 30 and circulate it among national scientists. Likewise the catch-at-size(CAS) updated from 1975-2007 and the conversion for this time period of catch-at-size (CAS) into catch-at-age(CAA) will be finalized by June 30.This schedule of tasks will allow updating the assessment with both VPA-Adapt and Multifan-CL models.Standardized CPUE series for all the main surface and longline fleets exploiting the North will be available byJune 30, 2009.190