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IV. C. Future Research Needs 



Some of the research needs for the western Pacific yellowfin tuna 

 include necessary data for stock assessment purposes: 



1) The magnitude and size composition of the large Philippine 

 surface catch of yellowfin in recent years should be accurately estimated 

 and historical catches documented. 



2) The problem of double reporting of catches should be resolved. 



3) Estimates of misidentified or unidentified yellowfin tuna in 

 the catches are needed. 



4) Size-composition data are needed from all the fisheries, 

 particularly the surface fisheries. 



5) Yield/recruit estimates are needed for stock assessment and 

 for production model analyses (which include surface catch and effort 

 data) . 



6) Effects of competition between surface and longline fisheries 

 should be further examined. 



7) The extent of mixing between fish available to surface and 

 longline gears should be examined. 



8) Additional estimates of the growth of yellowfin tuna in the 

 western Pacific are needed. 



IV.C.l. Suggested Approach and Methods 



1) Cooperative arrangements should be made with foreign 

 countries for the collection of yellowfin tuna fishery statistics, 

 particularly those from the Phill ippines. 



2) The extent of mixing between fish available to 

 surface and longline gears could be assessed by means of tagging 

 experiments. 



IV. D. Status of SWFC Data Base 



The data on catch, catch-per-effort, and length frequencies needed 

 for assessment studies on yellowfin in the Pacific are either inadequate or 

 are lacking and should therefore be secured. In particular, the large 



