| 英文摘要 |
This project attempts to realize current status of the Taiwanese jigger fleet operating in the Southwest Atlantic, and to standardize the fishing efforts that had been used in the waters.? In addition, we applied geo-statistic method to estimate annual total biomass, and fit annual abundance index (cpue) with a battery of variables to analyze the reason that might cause annual variation.? In 2009, the fleet caught 56,092 t squid, which account to 26.9% as compared to 2008, indicating a year of low production.? There were 74vessels involved in 2009’s practice, pouring 5930 d v fishing efforts in the SWA waters.? Based on an equilibrium yield of 165,000 t y-1, 2009’s production was low and plunged to a level of 66.0%.? On the other hand, the number of fishing vessel increased 10%, that rendered the catch per vessel downsized to 24.3% (3,114 t v-1 vs. 758 t v-1).? This result exhibited much low landings found in major ports.? Using Kriging volume to represent annual total biomass, we found that in 1999 ＆ 2000 practiced an over-exploitation in high recruitment, and in 2004 under-exploitation was found with low recruitment.? However, the model also estimated that 2007’s production was high but the exploitation was moderate, but 2008 was over-production.? Current (2009) year, the resources has been sufficiently utilized; i.e., production and total biomass are comparable. |