| 英文摘要 |
For swordfish in the Indian Ocean, the results of this study indicated that the current (2008) spawning biomass was about 40-50% of initial level and was about twice as MSY level. Even for the most pessimistic results, the fishery exploitation was below the MSY level and the spawning biomass was higher than the MSY level.??
??? For swordfish in the Atlantic Ocean, the CPUEs of the swordfish in the northern Atlantic Ocean were relative stable before 1990s but gradually decreased after 1995. The CPUE trend of the swordfish in the southern Atlantic Ocean was similar to that in the northern Atlantic Ocean, but it was relatively stable after 2000. Based on the stock assessment results, the estimates of fishing exploitation rate and spawning biomass for northern and southern Atlantic Ocean have been archived MSY levels.??? For southern bluefin tuna, the CPUEs obviously decreased in 2002, remained stable for two years, increased in 2006, and were stable thereafter. There was no obvious CPUE trend for fish older than 10 years. The CPUEs for fish of ages 6-9 slightly increased in 2006 and 2007. The CPUEs for young fish obviously increased in 2006 and 2007, especially for the fish of age 3-5 years and their CPUEs were about triple of those before 2006. However, the CPUEs for young fish substantially decreased thereafter. |