Update on task II size sampling based on Japanese tuna fleet operating in Uruguayan EEZ (2009-2011)

Between 2009 and 2011 Japanese-flagged tuna fishing vessels operated in Uruguay with a research fishing licence targeting Thunnus obesus. The fleet operated in Uruguayan jurisdictional waters (EEZ) and adjacent international waters of the Southwestern Atlantic Ocean. The present paper synthetize the information referred to blue shark (Prionace glauca) obtained by the Uruguayan Observer Program on board this fleet. The effort observed was 2,459,825 hooks in 1,060 sets with an observers’ coverage of the fleet of 100%. A total of 9,906 blue sharks were measured with a mean fork length (FL) of 152 cm (range 63-261) in the period 2009-2011. Size class distributions by sex and year are presented.