| 英文摘要 |
The aims of this project include (1) studying on age and growth of albacore in South Pacific (2) CPUE standardization and conversion between length and age for albacore caught by Taiwanese longliners in Indian. About the age and growth, the age character and length-frequency data were used to determine the age and growth of albacore in south Pacific in this study. The growth parameters have been estimated by using length frequency analysis in 2009. In this year, a total of 50 spines which their ring-radius were measured and 5 otoliths’ daily rings were counted. The age characters have been collecting continuously. About the CPUE standardization, the factors including year, quarter, subarea, bycatch, and interaction between quarter and subarea were used to standardize the CPUEs of albacore caught by Taiwan longliners in Indian for 1980-2008 from Generalized Linear Model (GLM). The yearly CPUE trend of Indian albacore thus obtained indicated that the values of CPUEs have decreased rapidly from early 1980s to 1990 while the values between 1991 and 2005 were decreased moderate and the values of standardized CPUE varied between 2.4 and 1.4. However, the CPUE reached the historic lowest value in 2006 but was steady to 2008. About the conversion between length and age, the VBGEs described in Huang et al.(1990) and Lee and Liu (1992) were used with Knife-edge cutting method to convert the? length composition into age composition. The results indicate that the majority of age caught by Taiwanese longliners in Indian are from age 4 to age 9 based on VBGE mentioned in Huang et al.(1990), while the majority of age are from age 3 to age 8 based on VBGE mentioned in Lee and Liu (1992). |
