| 英文摘要 |
The main tasks of this project are : (1) to use various methods to distinguish the fishing data targeted at albacore from targeted nonealbacore species and to use GLM model to standardize the Taiwanese distant long line fisheries effort statistics in the north Atlantic to obtain more correct CPUE trend; (2) to convert, based on age and growth equation, on Taiwanese CAS (catch at size) into CAA (catch in age) of Taiwanese albacore harvested in the North Atlantic; (3) to use ASPM to assess the albacore resource condition. The results indicated (1) the effort distribution for hook per basket of Taiwanese logbook data indicated two modes, and the most effort was separately found in 9-10 and 16-17 hooks; the bigger catch rate of albacore was obtained by 6-13 hooks; (2) to remove the effect of target species, the Taiwanese long-line logbook data identified as albacore targeting (less than 16 hooks per basket) from 1999 to 2012 were used here and shown that the yearly-standardized CPUE continuously increased up to 2004, thereafter, it remained relative stable (2005-2009), and then further increased during 2010-2011; (3) the main age of Taiwanese catch of albacore got bigger from 1981 to 2010; the main age of Taiwanese catch was 5-8 from 1981 to 1997, the one was 6-10 from 1999 to 2006, and the one was 7-11 from 2007 to 2010 . In general, albacore caught in area 32 is bigger than caught from area 31. The majority of Taiwanese catch of albacore is greater than age 3 in area 31 and is greater than age 4 in area 32; (4) the averages of last five year results obtained from ASPM for MSY,、BCUR /BMSY and FCUR/FMSY are 34500 ton, 0.952 and 0.61, respectively, and we agree the conclusion for Stock Conditions of Albacore Resource in the North Atlantic Ocean from ICCAT (2013) that the stock is slightly overfished, but is no longer undergoing overfishing. |
