Abstract:This study presented the catch, size, and distribution pattern of the blue shark by Taiwanese
small-scale tuna longline (STLL) fishery in the North Pacific. Catch estimated was based on the
landing data from the three major fishing ports for STLL fishery. The estimated annual catch of
blue sharks by Taiwanese small-scale tuna longline fisheries ranged from 6983 MT in 2013 to
14707 MT in 2011, with the mean of 11179 MT in 2001-2015. The mean size of females was
219.7 cm TL and that was 220.9 cm TL for males. Juvenile females and males were found in the
equatorial waters but adults were more often found in the subtropical waters. Seasonal variations
in the mean size for both sexes and the smallest mean sizes for both sexes were found in season 2.
The sex ratio was significantly different from 0.5 for every season except season 4.