
TY  - JOUR
A1  - Stevens, JD 
T1  - Blue and Mako Shark by-catch in the Japanese Longline Fishery off South-eastern Australia
JF  - Marine and Freshwater Research
JO  - Mar. Freshwater Res.
Y1  - 1992
VL  - 43
IS  - 1
SP  - 227
EP  - 236
KW  - 
UR  - https://doi.org/10.1071/MF9920227 
N2  - During the last 10 years, up to 70 Japanese longline vessels have fished Tasmanian waters  of the Australian Fishing Zone each season, targeting bluefin tuna (Thunnus maccoyii).  The average seasonal fishing effort in Tasmanian waters is about 3.3 million hooks,  and data from observers suggests that, this results in a by-catch of some 34 000 blue sharks  (Prionace glauca) each year, representing a weight of about 275 tonnes. In the last few years,  fishing effort has increased as the catch rates of southern bluefin tuna have declined. The sharks  are discarded after removal of the fins. The actual number of blue sharks hooked is much higher  than 34000 because many are released by either shaking or cutting them off the line, although  they are often damaged in the process. The majority of blue sharks caught are immature or  adolescent females. Smaller numbers of shortfin mako sharks (Isurus oxyrinchus) are also  caught and retained both for their fins and their meat. Tasmanian waters represent only one area  of the Australian Fishing Zone fished by Japanese longliners. 
ER  -

