For growth and age study, some tunas received an injection of Oxy-TetraCycline (OTC) an antibiotic commonly used for this type of study. To differentiate them from the normal tagged tunas that bear one or two yellow dart tags, a white tag was used on these fish. Altogether, 5,944 tuna have received a white tag or 3.5 % of the total. The species composition of the OTC tagged tuna is given in table 3 and figure 5c. We put more emphasis on YFT and BET because 1) they are our priority species and 2) otolith reading of SKJ has not proven yet their efficiency for estimating the age. We used two different tag sizes: 11.5 and 14.5 m. Only 496 tuna were OTC tagged with 11.5 cm tags and 5488 with 14.5 cm tags. The smaller tags also have a smaller diameter: about 1 mm instead of 2 mm for the longer ones which might make them less easy to spot at recovery.